Merge main into #2268; import both layers_or and popup_options, drop main's now-unreachable post-duplicate end_edit (the PR ends the edit first), adapt tests to main's kept empty Type-tool layer (f262e39c6)

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
2026-10-31 07:38:24 +00:00 · 2026-10-30 10:23:03 +07:00
commit c1c6e048f4
@@ -28,8 +28,8 @@ permissions:

 jobs:
  windows-arm64:
-    # Immutable supporting workflow revision until the new install contract lands upstream.
-    uses: storytold/craft-common-actions/.github/workflows/windows-arm64.yml@8bb4e5ab95443171104ad88113fe1ef9b0e5ce3f
+    # Intentionally tracked at @main (not SHA-pinned) so org-wide CI improvements, security fixes, and build optimizations propagate without PR churn across all craftapp repos.
+    uses: storytold/craft-common-actions/.github/workflows/windows-arm64.yml@main
    with:
      app-name: effectcraft
      app-dir: EffectCraft
@@ -144,3 +144,8 @@ as PhotoCraft does with `cargo xtask corpus`.
  GitHub profiles). Never hand-edit `contributors.json`.
 - Maintainers refresh the stats with `python3 ../../craftrules/scripts/contributors.py .` (it also
  re-verifies who wrote each `people.toml` entry; `--check` only verifies).
+
+## CI workflows
+- Workflows in `.github/workflows/` call the shared workflows in [`storytold/craft-common-actions`](https://github.com/storytold/craft-common-actions) at `@main`, with their inputs and secrets. No other jobs: if no shared workflow does what's needed, it doesn't go here.
+- Don't add or change CI in a feature or fix PR. If the existing workflows can't build or test a change, link an existing craft-common-actions issue or PR, or open a new issue, or a PR only for a small fix that is safe for every app and does not increase CI time.
+- Some workflow files here still run their own jobs. Don't add to them. Moving a job into craft-common-actions is its own task, never part of another PR, and the job stays here until a shared workflow runs it.
@@ -89,6 +89,8 @@ Screenshots of EffectCraft itself, rendered headlessly, showing only procedurall
  `crates/engine/presets/transitions.json` (sidecar `.attribution`).
 - Backgrounds animation presets (23: drifting gradients, fog, cloud and smoke, plasma and magma, cells and crystals, scrolling grids
  and checks, pulse rings, bokeh, light sweep): `crates/engine/presets/backgrounds.json` (sidecar `.attribution`).
+- Behaviors animation presets (22: wiggle, shake, float, orbit, bounce, drift, pendulum, spin, pulse, heartbeat, blink, strobe, flicker):
+  `crates/engine/presets/behaviors.json` (sidecar `.attribution`).
 - Sample scripts (File ▸ Scripts) and ScriptUI panel: `crates/engine/scripts/Rename Layers.jsx`,
  `crates/engine/scripts/Sort Layers by In Point.jsx`, `crates/engine/scripts/Create Null at Selected Layers.jsx`,
  `crates/engine/scripts/Render Queue Batch.jsx`, `crates/engine/scripts/ScriptUI Panels/Layer Tools.jsx`
@@ -30,3 +30,8 @@ EffectCraft is a clean-room, open-source, pure-Rust motion graphics and visual e
 - For UI work, **look at the result**. Headless (no window, works while the user is busy on the machine): `cargo run -p effectcraft-ui-egui --example snapshot -- --out ui.png --step '{"method":"engine.execute","params":{"command":"layer.select","params":{"layers":["#2"]}}}'` (steps are control-channel requests; `--script steps.jsonl`; `{"method":"snap","params":{"path":…}}` for intermediate shots). Or drive the live app via the control channel and take `ui.screenshot` (needs the window visible on screen).
 - After Effects reference: drive AE via ExtendScript (`osascript -e 'tell application "Adobe After Effects 2026" to DoScriptFile "x.jsx"'`) and capture only AE's window (`screencapture -l <windowid>`); keep captures in `plan/aftereffects/ref/` (gitignored), never commit them, never capture the Home screen.
 - Parallel agents: separate git worktrees and `CARGO_TARGET_DIR=target/agent-<name>`; keep every `Cargo.toml` valid (the `crates/*` glob).
+
+## CI workflows
+- Workflows in `.github/workflows/` call the shared workflows in [`storytold/craft-common-actions`](https://github.com/storytold/craft-common-actions) at `@main`, with their inputs and secrets. No other jobs: if no shared workflow does what's needed, it doesn't go here.
+- Don't add or change CI in a feature or fix PR. If the existing workflows can't build or test a change, link an existing craft-common-actions issue or PR, or open a new issue, or a PR only for a small fix that is safe for every app and does not increase CI time.
+- Some workflow files here still run their own jobs. Don't add to them. Moving a job into craft-common-actions is its own task, never part of another PR, and the job stays here until a shared workflow runs it.
@@ -7,12 +7,75 @@ work apply to everyone, people and AI agents alike, and they are not negotiable.

 You need [Rust](https://rustup.rs/) 1.95 or newer.

+On Linux the desktop app plays preview sound through `cpal`, so the build needs a usable ALSA
+pkg-config package: an `alsa.pc` that pkg-config can find, naming the linkable ALSA runtime
+library (usually `libasound.so.2`). `alsa-sys` runs pkg-config at build time; it does not compile
+ALSA's headers. Without a usable package the build fails at link time with an unrelated-looking
+error; `cargo xtask ci` probes pkg-config up front and names the package:
+
+```sh
+sudo dnf install alsa-lib-devel        # Fedora
+sudo apt install libasound2-dev        # Debian / Ubuntu
+sudo pacman -S alsa-lib                # Arch
+```
+
+If you cannot install the package, point `PKG_CONFIG_PATH` at a directory holding an `alsa.pc`
+whose `Libs` line names your system's `libasound` (usually `libasound.so.2`); every CI run needs
+that variable set.
+
 ```sh
 cargo run -p effectcraft -- --demo       # the desktop app, with the demo project
 cargo test --workspace
 cargo xtask ci                           # what every commit must pass
 ```

+The default `dev` profile keeps debug info to line tables: builds are fast and panics/backtraces
+still name the file and line, but a debugger cannot show local variables. For an interactive
+debugger session use the `dev-full` profile, which is the same build with full debug info:
+
+```sh
+cargo run --profile dev-full -p effectcraft -- --demo
+```
+
+### Windows
+
+The MSVC toolchain, rustup's default on Windows, is what the releases use: with the Visual Studio
+C++ build tools installed, the commands above work as they are.
+
+The GNU toolchain (`x86_64-pc-windows-gnu`) needs a current mingw-w64 GCC and binutils first on
+`PATH`. They provide the linker and the Windows import libraries, such as `libshlwapi.a` for
+opening links from the app. With MSYS2:
+
+```powershell
+C:\msys64\usr\bin\pacman.exe -S --needed mingw-w64-x86_64-gcc
+$env:PATH = "C:\msys64\mingw64\bin;$env:PATH"
+cargo +stable-x86_64-pc-windows-gnu run -p effectcraft -- --demo
+```
+
+An older MinGW earlier on `PATH` can break the build: CodeBlocks' GCC 8.1 fails to link
+`boa_engine` ([#1882](https://github.com/storytold/effectcraft/issues/1882)).
+
+Rust's bundled LLD and self-contained libraries don't include every import library EffectCraft
+needs, so on their own they stop with `unable to find library` for `-lshlwapi`, `-lktmw32`,
+`-lpropsys` and `-lversion` ([#1886](https://github.com/storytold/effectcraft/issues/1886)). To
+link that way, copy those four from mingw-w64 into a folder of its own and add that folder to the
+search path in your own Cargo config (`%USERPROFILE%\.cargo\config.toml`). Don't add all of
+mingw-w64's `lib` folder: its C runtime clashes with Rust's bundled one
+(`undefined symbol: DllEntryPoint`).
+
+```powershell
+New-Item -ItemType Directory -Force C:\gnu-import-libs
+foreach ($lib in "shlwapi", "ktmw32", "propsys", "version") {
+    Copy-Item "C:\msys64\mingw64\lib\lib$lib.a" C:\gnu-import-libs\
+}
+```
+
+```toml
+[target.x86_64-pc-windows-gnu]
+linker = "rust-lld"
+rustflags = ["-C", "link-self-contained=yes", "-L", "native=C:/gnu-import-libs"]
+```
+
 ## Ground rules

 - **Clean room.** Work from After Effects' public documentation and its observable behaviour only.
@@ -1454,6 +1454,7 @@ dependencies = [
 "kurbo",
 "log",
 "rayon",
+ "same-file",
 "serde",
 "serde_json",
 "thiserror 2.0.21",
@@ -1623,6 +1624,7 @@ name = "effectcraft-media"
 version = "0.18.0"
 dependencies = [
 "craft-docpath",
+ "effectcraft-color",
 "effectcraft-model",
 "effectcraft-pdf",
 "effectcraft-project",
@@ -1632,18 +1634,20 @@ dependencies = [
 "effectcraft-svg",
 "effectcraft-time",
 "exr",
+ "filmcraft-aac",
 "filmcraft-codecs",
 "filmcraft-color",
 "filmcraft-frame",
 "filmcraft-isobmff",
+ "filmcraft-matroska",
 "filmcraft-media",
+ "filmcraft-mpegts",
 "filmcraft-time",
 "gif",
 "image",
 "log",
 "rayon",
 "serde_json",
- "symphonia",
 "thiserror 2.0.21",
 ]

@@ -1653,6 +1657,7 @@ version = "0.18.0"
 dependencies = [
 "effectcraft-geom",
 "image",
+ "log",
 "miniz_oxide 0.9.1",
 "serde",
 "serde_json",
@@ -2244,8 +2249,8 @@ dependencies = [

 [[package]]
 name = "filmcraft-aac"
-version = "0.1.1"
-source = "git+https://github.com/storytold/filmcraft?rev=2c5ba7a72619935f0481f99d59409e0d1844b234#2c5ba7a72619935f0481f99d59409e0d1844b234"
+version = "0.8.0"
+source = "git+https://github.com/storytold/filmcraft?rev=09aaf9bf15d510eda1c413c0ccabb1d7e08b41c5#09aaf9bf15d510eda1c413c0ccabb1d7e08b41c5"
 dependencies = [
 "filmcraft-bitstream",
 "thiserror 2.0.21",
@@ -2253,40 +2258,57 @@ dependencies = [

 [[package]]
 name = "filmcraft-ac3"
-version = "0.1.1"
-source = "git+https://github.com/storytold/filmcraft?rev=2c5ba7a72619935f0481f99d59409e0d1844b234#2c5ba7a72619935f0481f99d59409e0d1844b234"
+version = "0.8.0"
+source = "git+https://github.com/storytold/filmcraft?rev=09aaf9bf15d510eda1c413c0ccabb1d7e08b41c5#09aaf9bf15d510eda1c413c0ccabb1d7e08b41c5"
 dependencies = [
 "thiserror 2.0.21",
 ]

 [[package]]
-name = "filmcraft-av1"
-version = "0.1.1"
-source = "git+https://github.com/storytold/filmcraft?rev=2c5ba7a72619935f0481f99d59409e0d1844b234#2c5ba7a72619935f0481f99d59409e0d1844b234"
+name = "filmcraft-apv"
+version = "0.8.0"
+source = "git+https://github.com/storytold/filmcraft?rev=09aaf9bf15d510eda1c413c0ccabb1d7e08b41c5#09aaf9bf15d510eda1c413c0ccabb1d7e08b41c5"
 dependencies = [
 "filmcraft-bitstream",
 "rayon",
 "thiserror 2.0.21",
 ]

+[[package]]
+name = "filmcraft-av1"
+version = "0.8.0"
+source = "git+https://github.com/storytold/filmcraft?rev=09aaf9bf15d510eda1c413c0ccabb1d7e08b41c5#09aaf9bf15d510eda1c413c0ccabb1d7e08b41c5"
+dependencies = [
+ "filmcraft-bitstream",
+ "rayon",
+ "thiserror 2.0.21",
+]
+
+[[package]]
+name = "filmcraft-avi"
+version = "0.8.0"
+source = "git+https://github.com/storytold/filmcraft?rev=09aaf9bf15d510eda1c413c0ccabb1d7e08b41c5#09aaf9bf15d510eda1c413c0ccabb1d7e08b41c5"
+
 [[package]]
 name = "filmcraft-bitstream"
-version = "0.1.1"
-source = "git+https://github.com/storytold/filmcraft?rev=2c5ba7a72619935f0481f99d59409e0d1844b234#2c5ba7a72619935f0481f99d59409e0d1844b234"
+version = "0.8.0"
+source = "git+https://github.com/storytold/filmcraft?rev=09aaf9bf15d510eda1c413c0ccabb1d7e08b41c5#09aaf9bf15d510eda1c413c0ccabb1d7e08b41c5"

 [[package]]
 name = "filmcraft-cfb"
-version = "0.1.1"
-source = "git+https://github.com/storytold/filmcraft?rev=2c5ba7a72619935f0481f99d59409e0d1844b234#2c5ba7a72619935f0481f99d59409e0d1844b234"
+version = "0.8.0"
+source = "git+https://github.com/storytold/filmcraft?rev=09aaf9bf15d510eda1c413c0ccabb1d7e08b41c5#09aaf9bf15d510eda1c413c0ccabb1d7e08b41c5"

 [[package]]
 name = "filmcraft-codecs"
-version = "0.1.1"
-source = "git+https://github.com/storytold/filmcraft?rev=2c5ba7a72619935f0481f99d59409e0d1844b234#2c5ba7a72619935f0481f99d59409e0d1844b234"
+version = "0.8.0"
+source = "git+https://github.com/storytold/filmcraft?rev=09aaf9bf15d510eda1c413c0ccabb1d7e08b41c5#09aaf9bf15d510eda1c413c0ccabb1d7e08b41c5"
 dependencies = [
 "filmcraft-aac",
 "filmcraft-ac3",
+ "filmcraft-apv",
 "filmcraft-av1",
+ "filmcraft-avi",
 "filmcraft-bitstream",
 "filmcraft-color",
 "filmcraft-dnx",
@@ -2296,6 +2318,7 @@ dependencies = [
 "filmcraft-isobmff",
 "filmcraft-matroska",
 "filmcraft-media",
+ "filmcraft-mpa",
 "filmcraft-mpeg2v",
 "filmcraft-mpegts",
 "filmcraft-mxf",
@@ -2303,9 +2326,11 @@ dependencies = [
 "filmcraft-opus",
 "filmcraft-prores",
 "filmcraft-time",
+ "filmcraft-vp8",
 "filmcraft-vp9",
 "image",
 "log",
+ "rayon",
 "symphonia",
 "thiserror 2.0.21",
 "web-time",
@@ -2313,16 +2338,25 @@ dependencies = [

 [[package]]
 name = "filmcraft-color"
-version = "0.1.1"
-source = "git+https://github.com/storytold/filmcraft?rev=2c5ba7a72619935f0481f99d59409e0d1844b234#2c5ba7a72619935f0481f99d59409e0d1844b234"
+version = "0.8.0"
+source = "git+https://github.com/storytold/filmcraft?rev=09aaf9bf15d510eda1c413c0ccabb1d7e08b41c5#09aaf9bf15d510eda1c413c0ccabb1d7e08b41c5"
 dependencies = [
 "serde",
 ]

+[[package]]
+name = "filmcraft-dng"
+version = "0.8.0"
+source = "git+https://github.com/storytold/filmcraft?rev=09aaf9bf15d510eda1c413c0ccabb1d7e08b41c5#09aaf9bf15d510eda1c413c0ccabb1d7e08b41c5"
+dependencies = [
+ "rayon",
+ "thiserror 2.0.21",
+]
+
 [[package]]
 name = "filmcraft-dnx"
-version = "0.1.1"
-source = "git+https://github.com/storytold/filmcraft?rev=2c5ba7a72619935f0481f99d59409e0d1844b234#2c5ba7a72619935f0481f99d59409e0d1844b234"
+version = "0.8.0"
+source = "git+https://github.com/storytold/filmcraft?rev=09aaf9bf15d510eda1c413c0ccabb1d7e08b41c5#09aaf9bf15d510eda1c413c0ccabb1d7e08b41c5"
 dependencies = [
 "filmcraft-bitstream",
 "rayon",
@@ -2331,8 +2365,8 @@ dependencies = [

 [[package]]
 name = "filmcraft-frame"
-version = "0.1.1"
-source = "git+https://github.com/storytold/filmcraft?rev=2c5ba7a72619935f0481f99d59409e0d1844b234#2c5ba7a72619935f0481f99d59409e0d1844b234"
+version = "0.8.0"
+source = "git+https://github.com/storytold/filmcraft?rev=09aaf9bf15d510eda1c413c0ccabb1d7e08b41c5#09aaf9bf15d510eda1c413c0ccabb1d7e08b41c5"
 dependencies = [
 "filmcraft-color",
 "filmcraft-time",
@@ -2342,16 +2376,16 @@ dependencies = [

 [[package]]
 name = "filmcraft-geom"
-version = "0.1.1"
-source = "git+https://github.com/storytold/filmcraft?rev=2c5ba7a72619935f0481f99d59409e0d1844b234#2c5ba7a72619935f0481f99d59409e0d1844b234"
+version = "0.8.0"
+source = "git+https://github.com/storytold/filmcraft?rev=09aaf9bf15d510eda1c413c0ccabb1d7e08b41c5#09aaf9bf15d510eda1c413c0ccabb1d7e08b41c5"
 dependencies = [
 "serde",
 ]

 [[package]]
 name = "filmcraft-h264"
-version = "0.1.1"
-source = "git+https://github.com/storytold/filmcraft?rev=2c5ba7a72619935f0481f99d59409e0d1844b234#2c5ba7a72619935f0481f99d59409e0d1844b234"
+version = "0.8.0"
+source = "git+https://github.com/storytold/filmcraft?rev=09aaf9bf15d510eda1c413c0ccabb1d7e08b41c5#09aaf9bf15d510eda1c413c0ccabb1d7e08b41c5"
 dependencies = [
 "filmcraft-bitstream",
 "rayon",
@@ -2360,8 +2394,8 @@ dependencies = [

 [[package]]
 name = "filmcraft-h264enc"
-version = "0.1.1"
-source = "git+https://github.com/storytold/filmcraft?rev=2c5ba7a72619935f0481f99d59409e0d1844b234#2c5ba7a72619935f0481f99d59409e0d1844b234"
+version = "0.8.0"
+source = "git+https://github.com/storytold/filmcraft?rev=09aaf9bf15d510eda1c413c0ccabb1d7e08b41c5#09aaf9bf15d510eda1c413c0ccabb1d7e08b41c5"
 dependencies = [
 "filmcraft-bitstream",
 "rayon",
@@ -2370,8 +2404,8 @@ dependencies = [

 [[package]]
 name = "filmcraft-hevc"
-version = "0.1.1"
-source = "git+https://github.com/storytold/filmcraft?rev=2c5ba7a72619935f0481f99d59409e0d1844b234#2c5ba7a72619935f0481f99d59409e0d1844b234"
+version = "0.8.0"
+source = "git+https://github.com/storytold/filmcraft?rev=09aaf9bf15d510eda1c413c0ccabb1d7e08b41c5#09aaf9bf15d510eda1c413c0ccabb1d7e08b41c5"
 dependencies = [
 "filmcraft-bitstream",
 "rayon",
@@ -2380,8 +2414,8 @@ dependencies = [

 [[package]]
 name = "filmcraft-interchange"
-version = "0.1.1"
-source = "git+https://github.com/storytold/filmcraft?rev=2c5ba7a72619935f0481f99d59409e0d1844b234#2c5ba7a72619935f0481f99d59409e0d1844b234"
+version = "0.8.0"
+source = "git+https://github.com/storytold/filmcraft?rev=09aaf9bf15d510eda1c413c0ccabb1d7e08b41c5#09aaf9bf15d510eda1c413c0ccabb1d7e08b41c5"
 dependencies = [
 "filmcraft-cfb",
 "filmcraft-color",
@@ -2397,8 +2431,8 @@ dependencies = [

 [[package]]
 name = "filmcraft-isobmff"
-version = "0.1.1"
-source = "git+https://github.com/storytold/filmcraft?rev=2c5ba7a72619935f0481f99d59409e0d1844b234#2c5ba7a72619935f0481f99d59409e0d1844b234"
+version = "0.8.0"
+source = "git+https://github.com/storytold/filmcraft?rev=09aaf9bf15d510eda1c413c0ccabb1d7e08b41c5#09aaf9bf15d510eda1c413c0ccabb1d7e08b41c5"
 dependencies = [
 "filmcraft-bitstream",
 "thiserror 2.0.21",
@@ -2406,15 +2440,16 @@ dependencies = [

 [[package]]
 name = "filmcraft-matroska"
-version = "0.1.1"
-source = "git+https://github.com/storytold/filmcraft?rev=2c5ba7a72619935f0481f99d59409e0d1844b234#2c5ba7a72619935f0481f99d59409e0d1844b234"
+version = "0.8.0"
+source = "git+https://github.com/storytold/filmcraft?rev=09aaf9bf15d510eda1c413c0ccabb1d7e08b41c5#09aaf9bf15d510eda1c413c0ccabb1d7e08b41c5"

 [[package]]
 name = "filmcraft-media"
-version = "0.1.1"
-source = "git+https://github.com/storytold/filmcraft?rev=2c5ba7a72619935f0481f99d59409e0d1844b234#2c5ba7a72619935f0481f99d59409e0d1844b234"
+version = "0.8.0"
+source = "git+https://github.com/storytold/filmcraft?rev=09aaf9bf15d510eda1c413c0ccabb1d7e08b41c5#09aaf9bf15d510eda1c413c0ccabb1d7e08b41c5"
 dependencies = [
 "filmcraft-color",
+ "filmcraft-dng",
 "filmcraft-frame",
 "filmcraft-time",
 "image",
@@ -2423,10 +2458,19 @@ dependencies = [
 "thiserror 2.0.21",
 ]

+[[package]]
+name = "filmcraft-mpa"
+version = "0.8.0"
+source = "git+https://github.com/storytold/filmcraft?rev=09aaf9bf15d510eda1c413c0ccabb1d7e08b41c5#09aaf9bf15d510eda1c413c0ccabb1d7e08b41c5"
+dependencies = [
+ "filmcraft-bitstream",
+ "thiserror 2.0.21",
+]
+
 [[package]]
 name = "filmcraft-mpeg2v"
-version = "0.1.1"
-source = "git+https://github.com/storytold/filmcraft?rev=2c5ba7a72619935f0481f99d59409e0d1844b234#2c5ba7a72619935f0481f99d59409e0d1844b234"
+version = "0.8.0"
+source = "git+https://github.com/storytold/filmcraft?rev=09aaf9bf15d510eda1c413c0ccabb1d7e08b41c5#09aaf9bf15d510eda1c413c0ccabb1d7e08b41c5"
 dependencies = [
 "rayon",
 "thiserror 2.0.21",
@@ -2434,31 +2478,31 @@ dependencies = [

 [[package]]
 name = "filmcraft-mpegts"
-version = "0.1.1"
-source = "git+https://github.com/storytold/filmcraft?rev=2c5ba7a72619935f0481f99d59409e0d1844b234#2c5ba7a72619935f0481f99d59409e0d1844b234"
+version = "0.8.0"
+source = "git+https://github.com/storytold/filmcraft?rev=09aaf9bf15d510eda1c413c0ccabb1d7e08b41c5#09aaf9bf15d510eda1c413c0ccabb1d7e08b41c5"
 dependencies = [
 "thiserror 2.0.21",
 ]

 [[package]]
 name = "filmcraft-mxf"
-version = "0.1.1"
-source = "git+https://github.com/storytold/filmcraft?rev=2c5ba7a72619935f0481f99d59409e0d1844b234#2c5ba7a72619935f0481f99d59409e0d1844b234"
+version = "0.8.0"
+source = "git+https://github.com/storytold/filmcraft?rev=09aaf9bf15d510eda1c413c0ccabb1d7e08b41c5#09aaf9bf15d510eda1c413c0ccabb1d7e08b41c5"

 [[package]]
 name = "filmcraft-ogg"
-version = "0.1.1"
-source = "git+https://github.com/storytold/filmcraft?rev=2c5ba7a72619935f0481f99d59409e0d1844b234#2c5ba7a72619935f0481f99d59409e0d1844b234"
+version = "0.8.0"
+source = "git+https://github.com/storytold/filmcraft?rev=09aaf9bf15d510eda1c413c0ccabb1d7e08b41c5#09aaf9bf15d510eda1c413c0ccabb1d7e08b41c5"

 [[package]]
 name = "filmcraft-opus"
-version = "0.1.1"
-source = "git+https://github.com/storytold/filmcraft?rev=2c5ba7a72619935f0481f99d59409e0d1844b234#2c5ba7a72619935f0481f99d59409e0d1844b234"
+version = "0.8.0"
+source = "git+https://github.com/storytold/filmcraft?rev=09aaf9bf15d510eda1c413c0ccabb1d7e08b41c5#09aaf9bf15d510eda1c413c0ccabb1d7e08b41c5"

 [[package]]
 name = "filmcraft-project"
-version = "0.1.1"
-source = "git+https://github.com/storytold/filmcraft?rev=2c5ba7a72619935f0481f99d59409e0d1844b234#2c5ba7a72619935f0481f99d59409e0d1844b234"
+version = "0.8.0"
+source = "git+https://github.com/storytold/filmcraft?rev=09aaf9bf15d510eda1c413c0ccabb1d7e08b41c5#09aaf9bf15d510eda1c413c0ccabb1d7e08b41c5"
 dependencies = [
 "filmcraft-color",
 "filmcraft-geom",
@@ -2471,8 +2515,8 @@ dependencies = [

 [[package]]
 name = "filmcraft-prores"
-version = "0.1.1"
-source = "git+https://github.com/storytold/filmcraft?rev=2c5ba7a72619935f0481f99d59409e0d1844b234#2c5ba7a72619935f0481f99d59409e0d1844b234"
+version = "0.8.0"
+source = "git+https://github.com/storytold/filmcraft?rev=09aaf9bf15d510eda1c413c0ccabb1d7e08b41c5#09aaf9bf15d510eda1c413c0ccabb1d7e08b41c5"
 dependencies = [
 "filmcraft-bitstream",
 "rayon",
@@ -2481,16 +2525,24 @@ dependencies = [

 [[package]]
 name = "filmcraft-time"
-version = "0.1.1"
-source = "git+https://github.com/storytold/filmcraft?rev=2c5ba7a72619935f0481f99d59409e0d1844b234#2c5ba7a72619935f0481f99d59409e0d1844b234"
+version = "0.8.0"
+source = "git+https://github.com/storytold/filmcraft?rev=09aaf9bf15d510eda1c413c0ccabb1d7e08b41c5#09aaf9bf15d510eda1c413c0ccabb1d7e08b41c5"
 dependencies = [
 "serde",
 ]

+[[package]]
+name = "filmcraft-vp8"
+version = "0.8.0"
+source = "git+https://github.com/storytold/filmcraft?rev=09aaf9bf15d510eda1c413c0ccabb1d7e08b41c5#09aaf9bf15d510eda1c413c0ccabb1d7e08b41c5"
+dependencies = [
+ "thiserror 2.0.21",
+]
+
 [[package]]
 name = "filmcraft-vp9"
-version = "0.1.1"
-source = "git+https://github.com/storytold/filmcraft?rev=2c5ba7a72619935f0481f99d59409e0d1844b234#2c5ba7a72619935f0481f99d59409e0d1844b234"
+version = "0.8.0"
+source = "git+https://github.com/storytold/filmcraft?rev=09aaf9bf15d510eda1c413c0ccabb1d7e08b41c5#09aaf9bf15d510eda1c413c0ccabb1d7e08b41c5"
 dependencies = [
 "filmcraft-bitstream",
 "rayon",
@@ -4241,7 +4293,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "7d8fae84b431384b68627d0f9b3b1245fcf9f46f6c0e3dc902e9dce64edd1967"
 dependencies = [
 "libc",
- "windows-sys 0.45.0",
+ "windows-sys 0.61.2",
 ]

 [[package]]
@@ -4833,9 +4885,9 @@ dependencies = [

 [[package]]
 name = "roxmltree"
-version = "0.21.1"
+version = "0.21.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f1964b10c76125c36f8afe190065a4bf9a87bf324842c05701330bba9f1cacbb"
+checksum = "9da7f59328b09405b181fee1018925fad50f157afb43c0c0f5c522c256dd5907"
 dependencies = [
 "memchr",
 ]
@@ -7198,6 +7250,7 @@ name = "xtask"
 version = "0.18.0"
 dependencies = [
 "chrono",
+ "pkg-config",
 "serde_json",
 "tempfile",
 ]
@@ -7417,9 +7470,9 @@ dependencies = [

 [[package]]
 name = "zip"
-version = "9.1.0"
+version = "9.1.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "2886b00003a72c4ccee3f42cfc34908d33b2508a74d827dc2a4244706475c704"
+checksum = "1156b39d142a34b999c2310a50455e0cb3760bf7efad0122f796d813bee26ccb"
 dependencies = [
 "crc32fast",
 "flate2",
@@ -74,32 +74,33 @@ skrifa = { version = "0.44", default-features = false, features = ["std"] }
 harfrust = { version = "0.12", default-features = false, features = ["std"] }
 exr = "1.74"
 image = { version = "0.25", default-features = false, features = ["png", "jpeg"] }
+same-file = "1.0"

 # media codecs + containers: FilmCraft's pure-Rust crates, pinned to a revision (plan/adr/0001).
 # Only `crates/media`, `crates/export` and `crates/interchange` may depend on these.
-filmcraft-codecs = { git = "https://github.com/storytold/filmcraft", rev = "2c5ba7a72619935f0481f99d59409e0d1844b234" }
-filmcraft-media = { git = "https://github.com/storytold/filmcraft", rev = "2c5ba7a72619935f0481f99d59409e0d1844b234" }
-filmcraft-frame = { git = "https://github.com/storytold/filmcraft", rev = "2c5ba7a72619935f0481f99d59409e0d1844b234" }
-filmcraft-color = { git = "https://github.com/storytold/filmcraft", rev = "2c5ba7a72619935f0481f99d59409e0d1844b234" }
-filmcraft-time = { git = "https://github.com/storytold/filmcraft", rev = "2c5ba7a72619935f0481f99d59409e0d1844b234" }
+filmcraft-codecs = { git = "https://github.com/storytold/filmcraft", rev = "09aaf9bf15d510eda1c413c0ccabb1d7e08b41c5" }
+filmcraft-media = { git = "https://github.com/storytold/filmcraft", rev = "09aaf9bf15d510eda1c413c0ccabb1d7e08b41c5" }
+filmcraft-frame = { git = "https://github.com/storytold/filmcraft", rev = "09aaf9bf15d510eda1c413c0ccabb1d7e08b41c5" }
+filmcraft-color = { git = "https://github.com/storytold/filmcraft", rev = "09aaf9bf15d510eda1c413c0ccabb1d7e08b41c5" }
+filmcraft-time = { git = "https://github.com/storytold/filmcraft", rev = "09aaf9bf15d510eda1c413c0ccabb1d7e08b41c5" }
 # encoders + muxer (crates/export)
-filmcraft-h264enc = { git = "https://github.com/storytold/filmcraft", rev = "2c5ba7a72619935f0481f99d59409e0d1844b234" }
-filmcraft-prores = { git = "https://github.com/storytold/filmcraft", rev = "2c5ba7a72619935f0481f99d59409e0d1844b234" }
-filmcraft-aac = { git = "https://github.com/storytold/filmcraft", rev = "2c5ba7a72619935f0481f99d59409e0d1844b234" }
-filmcraft-isobmff = { git = "https://github.com/storytold/filmcraft", rev = "2c5ba7a72619935f0481f99d59409e0d1844b234" }
+filmcraft-h264enc = { git = "https://github.com/storytold/filmcraft", rev = "09aaf9bf15d510eda1c413c0ccabb1d7e08b41c5" }
+filmcraft-prores = { git = "https://github.com/storytold/filmcraft", rev = "09aaf9bf15d510eda1c413c0ccabb1d7e08b41c5" }
+filmcraft-aac = { git = "https://github.com/storytold/filmcraft", rev = "09aaf9bf15d510eda1c413c0ccabb1d7e08b41c5" }
+filmcraft-isobmff = { git = "https://github.com/storytold/filmcraft", rev = "09aaf9bf15d510eda1c413c0ccabb1d7e08b41c5" }
+# container headers read for AAC channel layouts (crates/media)
+filmcraft-matroska = { git = "https://github.com/storytold/filmcraft", rev = "09aaf9bf15d510eda1c413c0ccabb1d7e08b41c5" }
+filmcraft-mpegts = { git = "https://github.com/storytold/filmcraft", rev = "09aaf9bf15d510eda1c413c0ccabb1d7e08b41c5" }
 # decoder used as the round-trip oracle of effectcraft-opusenc (crates/export dev-dependency)
-filmcraft-opus = { git = "https://github.com/storytold/filmcraft", rev = "2c5ba7a72619935f0481f99d59409e0d1844b234" }
-filmcraft-vp9 = { git = "https://github.com/storytold/filmcraft", rev = "2c5ba7a72619935f0481f99d59409e0d1844b234" }
+filmcraft-opus = { git = "https://github.com/storytold/filmcraft", rev = "09aaf9bf15d510eda1c413c0ccabb1d7e08b41c5" }
+filmcraft-vp9 = { git = "https://github.com/storytold/filmcraft", rev = "09aaf9bf15d510eda1c413c0ccabb1d7e08b41c5" }
 # decoders used as the round-trip oracles of effectcraft-hevcenc / effectcraft-av1enc (dev-dependencies only)
-filmcraft-hevc = { git = "https://github.com/storytold/filmcraft", rev = "2c5ba7a72619935f0481f99d59409e0d1844b234" }
-filmcraft-av1 = { git = "https://github.com/storytold/filmcraft", rev = "2c5ba7a72619935f0481f99d59409e0d1844b234" }
+filmcraft-hevc = { git = "https://github.com/storytold/filmcraft", rev = "09aaf9bf15d510eda1c413c0ccabb1d7e08b41c5" }
+filmcraft-av1 = { git = "https://github.com/storytold/filmcraft", rev = "09aaf9bf15d510eda1c413c0ccabb1d7e08b41c5" }
 # timeline interchange (EDL, FCP7 XML, FCPXML, OTIO) for Premiere Pro interop (crates/interchange only)
-filmcraft-interchange = { git = "https://github.com/storytold/filmcraft", rev = "2c5ba7a72619935f0481f99d59409e0d1844b234" }
-filmcraft-project = { git = "https://github.com/storytold/filmcraft", rev = "2c5ba7a72619935f0481f99d59409e0d1844b234" }
-filmcraft-geom = { git = "https://github.com/storytold/filmcraft", rev = "2c5ba7a72619935f0481f99d59409e0d1844b234" }
-# The symphonia filmcraft-codecs already builds, named only to turn on its AIFF reader: the pinned
-# rev enables wav alone (FilmCraft main enables aiff too). Drop it when the pin moves past that.
-symphonia = { version = "0.5.5", default-features = false, features = ["aiff"] }
+filmcraft-interchange = { git = "https://github.com/storytold/filmcraft", rev = "09aaf9bf15d510eda1c413c0ccabb1d7e08b41c5" }
+filmcraft-project = { git = "https://github.com/storytold/filmcraft", rev = "09aaf9bf15d510eda1c413c0ccabb1d7e08b41c5" }
+filmcraft-geom = { git = "https://github.com/storytold/filmcraft", rev = "09aaf9bf15d510eda1c413c0ccabb1d7e08b41c5" }

 # gpu (the same wgpu eframe / egui-wgpu use)
 wgpu = { version = "30.0.1", features = ["fragile-send-sync-non-atomic-wasm"] }
@@ -131,6 +132,8 @@ sys-locale = "0.3"
 # filmcraft-prores = { path = "../filmcraft/crates/prores" }
 # filmcraft-aac = { path = "../filmcraft/crates/aac" }
 # filmcraft-isobmff = { path = "../filmcraft/crates/isobmff" }
+# filmcraft-matroska = { path = "../filmcraft/crates/matroska" }
+# filmcraft-mpegts = { path = "../filmcraft/crates/mpegts" }

 [workspace.lints.rust]
 unsafe_code = "forbid"
@@ -153,6 +156,13 @@ opt-level = 1
 # Panics and backtraces keep file and line; full debug info only made the many test binaries large.
 debug = "line-tables-only"

+# Same settings as `dev`, but with full debug info for interactive debugger sessions: local
+# variables, parameters and column breakpoints work. Use `--profile dev-full` when debugging;
+# everything else stays on the fast default. See CONTRIBUTING.md, "Setup".
+[profile.dev-full]
+inherits = "dev"
+debug = true
+
 # Pixel hot loops: keep debug builds interactive.
 [profile.dev.package.effectcraft-raster]
 opt-level = 3
@@ -20,7 +20,7 @@

 <p align="center">
  A free, open-source compositor: compositions, layers,
-  keyframes, 306 effects, layer styles, expressions, 3D cameras and lights, and a render queue, native on macOS,
+  keyframes, 308 effects, layer styles, expressions, 3D cameras and lights, and a render queue, native on macOS,
  Windows and Linux, and in the browser. Young, moving fast, and already usable.
 </p>

@@ -84,9 +84,10 @@ a few places where it matters to us:
  without a plugin.
 - **A project file you can read.** Projects are versioned JSON (`.ecproj`), so they diff cleanly
  in version control.
- **Everything is scriptable.** Every menu item, timeline drag and property edit goes through one
-  command registry, so the same actions are reachable from a command line, a JSON control
-  channel and an MCP server for agents.
+- **Everything is scriptable.** Menu actions, timeline edits and property changes are exposed as
+  commands. Engine commands are available through the CLI, JSON control channel and MCP;
+  UI-only commands use the frontend dispatcher and can be invoked through the control channel
+  or an attached MCP bridge.
 - **No FFmpeg.** Video and audio decoding and encoding are pure Rust: FilmCraft's codecs and
  EffectCraft's own VP9, AV1, HEVC and Opus encoders.

@@ -126,7 +127,7 @@ or into the Timeline, between layers and at the time you point to.

 ## Effects

-306 built-in effects across its categories, each with its parameter names, order and
+308 built-in effects across its categories, each with its parameter names, order and
 defaults: blur and sharpen, channel, color correction (Curves, Levels, Hue/Saturation, a full
 color-grading panel…), distort (Warp, Bulge, Turbulent Displace, CC Power Pin…), generate (Fractal Noise,
 Gradient Ramp, Stroke, Write-on, Audio Spectrum…), keying, matte, noise and grain, perspective,
@@ -155,7 +156,7 @@ tools, and Front, Top, Left and Custom views.

 A dedicated Render Queue, with Render Settings and Output Modules: **H.264** MP4 and
 **ProRes** MOV (Proxy to 4444 XQ with alpha) with audio, **HEVC** (Main / Main 10) and **AV1**
-MP4, **WebM** (VP9 with inter frames and alpha, or AV1; Opus audio), PNG, JPEG, TIFF and 32-bit EXR sequences, animated GIF and WAV/AIFF. Field
+MP4, **WebM** (VP9 with inter frames and alpha, or AV1; Opus audio), PNG, JPEG, TIFF, Targa and 32-bit EXR sequences, animated GIF and WAV/AIFF. Field
 rendering with 3:2 pulldown, effect/solo/guide/depth overrides, crop, region of interest and
 resize, Render Settings and Output Module templates with defaults, post-render actions, storage
 overflow and render logs. The same queue runs from the command line. Every encoder is pure
@@ -173,8 +174,10 @@ cannot express; File ▸ Import ▸ Lottie… opens one as a new composition.

 ## Built for agents

-Everything you can do from a menu is a command with an id, and agents can reach every one of
-them:
+Engine commands are available through the CLI, JSON control channel and MCP. UI-only commands
+need the running app's frontend dispatcher: complete menu access requires the app's control
+channel or an attached MCP bridge. Headless MCP sessions expose supported engine commands,
+but not UI-only commands or bridge-only `ui_*` tools.

 - **MCP server:** `effectcraft-cli mcp` speaks the Model Context Protocol over stdio, headless
  or bridged to the running app (`--bridge 9877`). Tools cover commands, the project and property
@@ -228,7 +231,7 @@ tests, layering, asset attribution and the WebAssembly build). See [CONTRIBUTING
 ## Where it stands

 EffectCraft is young: its first commit was on 1 October 2026. A comprehensive feature set
-exists, including 306 effects, but breadth is not the same as full maturity across every edge
+exists, including 308 effects, but breadth is not the same as full maturity across every edge
 case. Today it's a good place to try things and to tell us what breaks. It isn't yet recommended
 for production client work. In particular:

@@ -2,7 +2,7 @@

 **Stage: alpha** · next: beta, ~30 points of "ready for real work" and ~350–620 h away

-> **Last reviewed:** 2026-10-12 · **Last updated:** 2026-10-12 · **Change:** minor (open-issue count, crash list and localization share re-audited against `upstream/main` 470ea7a3) · **Target:** Adobe After Effects 2026 (26.5.0.89)
+> **Last reviewed:** 2026-10-22 · **Last updated:** 2026-10-30 · **Change:** minor (features of 30 October in the progress log: text Line Join, Timeline drag-reorder and multi-select of effects, viewer edge pan, ScriptUI drag capture and dock size; previously: localization recount after #1774) · **Target:** Adobe After Effects 2026 (26.5.0.89)

 EffectCraft aims to do what After Effects does, with the same panels, menus and behaviour, written
 from scratch in Rust. This page is the one-page summary; the evidence is in
@@ -51,7 +51,7 @@ Linux/Windows reliability (30–50 h) and depth in animation, masks, effects and
 | UI/UX fidelity | 65% | 60–120 | [ui-parity.md](docs/ui-parity.md) |
 | File formats | 50% | 130–230 | [file-format-parity.md](docs/file-format-parity.md) |
 | Hardware | 40% | 60–120 | [hardware-parity.md](docs/hardware-parity.md) |
-| Localization | 18% | 60–110 + review | [localization-parity.md](docs/localization-parity.md) |
+| Localization | 24% | 60–110 + review | [localization-parity.md](docs/localization-parity.md) |
 | Performance | 35% | 50–100 | [gaps.md](docs/gaps.md#g5-performance-at-real-world-scale) |
 | Stability | 45% | 40–80 | [gaps.md](docs/gaps.md#g3-stability-and-a-green-main) |
 | Platforms | 65% | 30–60 | [gaps.md](docs/gaps.md#g2-real-user-reliability-on-every-platform) |
@@ -80,24 +80,24 @@ Weights and evidence per row: [target-app-parity.md](docs/target-app-parity.md#b

 ## Languages

-UI strings translated out of ≈ 3,900 (detail: [localization-parity.md](docs/localization-parity.md)).
+UI strings translated out of ≈ 4,200 (detail: [localization-parity.md](docs/localization-parity.md)).

 | Language | Status | % |
 |---|---|---:|
 | English | full | 100% |
-| Simplified Chinese | partial (menus, part of the panels) | 29% |
-| Spanish | menus only | 16% |
+| Simplified Chinese | partial (menus, most of the panels) | 46% |
+| Spanish | menus only | 29% |
 | Hindi | none | 0% |
 | Arabic | none | 0% |
 | French | menus only | 16% |
-| Portuguese (Brazil) | partial (menus, part of the panels) | 26% |
+| Portuguese (Brazil) | partial (menus, part of the panels) | 34% |
 | Indonesian | none | 0% |
-| Japanese | partial (menus, part of the panels) | 27% |
+| Japanese | partial (menus, most of the panels) | 46% |
 | German | menus only | 16% |
 | Korean | none | 0% |
 | Vietnamese | none | 0% |

-Also shipped: Traditional Chinese (partial, 29%), Ukrainian (partial, 29%), Czech (partial, 29%), Georgian (partial, 38%; native-speaker reviewed) and Russian (menus only, 16%). No other language has had
+Also shipped: Traditional Chinese (partial, 38%), Ukrainian (partial, 29%), Czech (partial, 29%), Polish (partial, 34%), Georgian (partial, 39%; native-speaker reviewed) and Russian (menus only, 15%). No other language has had
 native-speaker review.

 ## Upcoming
@@ -117,10 +117,33 @@ Come tell us what matters most to you on [Discord](https://discord.gg/artcraft).

 ## Progress log

+- 2026-10-30: Text strokes take a Line Join (Miter, Round or Bevel) in the Character panel,
+  Miter for new text as in After Effects (#2077). In the Timeline, effects, masks and shape items
+  drag to a new place in their stack (#2210) and Shift-click adds them to the selection, so one
+  animation preset can hold several (#2552). The Composition panel pans while a mask vertex is
+  held at its edge (#999). Effect buffers that pad a small layer stay within a memory budget
+  (#2261); an MP4 lasts as long as its edit list shows (#2592); the Render Queue's times tick
+  between frames (#2593). ScriptUI drags keep their control past the window edge with
+  `MouseEvent.buttons` (#2584), and docked panels get their dock's size and `onResize` (#2585).
+- 2026-10-28: A shape layer's Rectangle and Ellipse Size get the Constrain Proportions chain
+  that Scale has, so a circle stays a circle while its size is typed, scrubbed or keyed; it
+  starts off, so existing shapes behave as before (#2489).
+- 2026-10-24: Shape layers have the Wiggle Transform path operation (Contents ▸ Add, or
+  `layer.addShapeItem {kind: "wiggler"}`): it wiggles the anchor point, position, scale and
+  rotation of the paths above it by random amounts that change over time, up to the Transform
+  values it holds. The copies of a Repeater above it wiggle independently as far as its
+  Correlation allows; with the Repeater below it, they wiggle together.
+- 2026-10-22: Localization: the panel/dialog catalogs gain 303 rows in Japanese, Simplified
+  Chinese and Traditional Chinese — panel tabs, form and dialog labels, panel context menus,
+  tracker/graph/text-panel controls, File-panel footers and credits. Recounted after #1774:
+  Japanese is 1,923 of ≈ 4,200 interface strings (46%, with 297 effect names); the Chinese
+  panel catalogs hold 998 (Simplified) and 951 (Traditional) rows, and Simplified Chinese is
+  46% with its 307 effect names; the overall share is ≈ 24%.
 - 2026-10-16: Convert To Bezier Path turns a shape layer's Rectangle, Ellipse or Polystar
  path into an editable Path 1 with the same geometry, as After Effects does; it used to
  apply to mask RotoBezier only, so a parametric shape path could not be converted at all
  and its vertices could not be edited or animated (#932).
+- 2026-10-14: Georgian (`ka`): every menu row, every panel-catalog row the Chinese catalogs have plus 195 Georgian-only ones, and the effect names and categories; Match System for `ka` / `ka-GE` / `ka_GE.UTF-8` locales. Reviewed by a native speaker.
 - 2026-10-12: Roto Brush span edits report strokes outside a trimmed layer without panicking;
  strokes and undo history are preserved so restoring the timing allows the span edit again.
 - 2026-10-11: Ukrainian panels caught up with the Chinese catalogs. The 95 rows the panel
@@ -135,7 +158,6 @@ Come tell us what matters most to you on [Discord](https://discord.gg/artcraft).
  follow the shared standard: `docs/parity.md` became `docs/target-app-parity.md`; new
  `docs/roadmap.md`, `localization-parity.md`, `file-format-parity.md`, `hardware-parity.md`,
  `ui-parity.md`, `effects-parity.md` and `scripting-parity.md`.
- 2026-10-14: Georgian (`ka`): every menu row, every panel-catalog row the Chinese catalogs have plus 195 Georgian-only ones, and the effect names and categories; Match System for `ka` / `ka-GE` / `ka_GE.UTF-8` locales. Reviewed by a native speaker.
 - 2026-10-10: Spanish (#460) and Brazilian Portuguese (#217) menu translations.
 - 2026-10-10: Japanese now translates the interface below the menu bar too: `crates/ui-egui/src/i18n/ui.rs` has a Japanese table with the same 396 rows as the Chinese ones (panels, dialogs, buttons and tooltips; the shape test keeps the three catalogs listing the same source strings). Menus were already Japanese.
 - 2026-10-09: Ukrainian now covers all 396 current panel-catalog strings, including dialogs, buttons and tooltips, alongside its menu translation. The catalog keeps the same source keys and placeholder counts as the Chinese catalogs; missing or engine-generated text still falls back to English.
@@ -155,11 +177,13 @@ Come tell us what matters most to you on [Discord](https://discord.gg/artcraft).

 | Date | Change | Summary |
 |---|---|---|
+| 2026-10-30 | minor | Progress log: text Line Join, Timeline drag-reorder and Shift multi-select of effects, viewer edge pan, effect padding budget, MP4 edit-list duration, Render Queue clock, ScriptUI drag capture and docked-panel size |
+| 2026-10-22 | minor | Localization: 300 more panel/dialog rows in Japanese and the Chinese catalogs, plus the review's three missing rows (Basic, Advanced, Play/Stop) — panel tabs, form and dialog labels, context menus, tracker/graph/text-panel controls, File-panel footers, credits; language shares recounted after #1774 (Japanese 27% → 46% with 297 effect names, Simplified Chinese 29% → 46% with 307 effect names, Traditional Chinese 29% → 38%, overall 18% → 24%) |
 | 2026-10-12 | minor | Open-issue count (134 to 216), crash list and localization share (12% to 18%) updated to match docs/gaps.md |
 | 2026-10-12 | patch | Roto Brush span validation after trimming; command regressions for both layer edges |
+| 2026-10-12 | minor | Shared PDF object/xref parsing with bounded app-owned conversion and preserved stream budgets; drawing, EPS and image/font policy remain unchanged |
 | 2026-10-10 | minor | Hours to ≈ 95% for each audience |
 | 2026-10-10 | minor | Headline adds mainstream practitioner (≈ 47%) and essentials user (≈ 52%) |
-| 2026-10-12 | minor | Shared PDF object/xref parsing with bounded app-owned conversion and preserved stream budgets; drawing, EPS and image/font policy remain unchanged |
-| 2026-10-10 | minor | Stage checked against the new core-workflow gate (all six pass; still alpha) |
 | 2026-10-10 | major | Rewritten to the shared progress-docs standard: stage, two numbers, dimensions, features, languages, upcoming, progress log; milestones moved to docs/roadmap.md |
+| 2026-10-10 | minor | Stage checked against the new core-workflow gate (all six pass; still alpha) |
 | 2026-10-05 | major | Two numbers (breadth vs real use) and workstreams G1–G9 |
@@ -7,11 +7,12 @@
 //! effectcraft-cli exec --list [--filter TEXT] [--schemas]     list engine commands (as `commands`)
 //! effectcraft-cli run <id> <json> [<id> <json> …]             run several commands in order
 //! effectcraft-cli run --args-file F                           the same, one argument per line of F
+//! effectcraft-cli run --commands FILE|-                         steps {"command", "params"} from FILE or stdin
 //! effectcraft-cli props <comp> <layer> [--flat] [--time S]    a layer's property tree (with paths)
 //! effectcraft-cli get <comp> <layer> <path> [--time S]        read a property
 //! effectcraft-cli set <comp> <layer> <path> <value> [--time S] [--expression E]
 //! effectcraft-cli render-frame [--comp C] [--time S|--frame N] [--max-side PX|--scale K] [--out F.png] [--transparent]
-//! effectcraft-cli render [--comp C] --out FILE [--format h264|hevc|av1|prores|webm|png|jpeg|tiff|exr|gif|wav|aiff] [--start S] [--end S]
+//! effectcraft-cli render [--comp C] --out FILE [--format h264|hevc|av1|prores|webm|png|jpeg|tiff|exr|tga|gif|wav|aiff] [--start S] [--end S]
 //!     [--work-area] [--fps N] [--resolution full|half|third|quarter|K] [--quality best|draft] [--channels rgb|rgba]
 //!     [--jpeg-quality N] [--bitrate KBPS] [--prores proxy|lt|standard|hq|4444|4444xq] [--audio auto|on|off]
 //!     [--profile main|main10] [--level auto|4.1] [--rate-control bitrate|quality] [--video-quality 1-100]
@@ -98,6 +99,10 @@ const USAGE: &str = "usage: effectcraft-cli <info|commands|exec|run|props|get|se
  exec <command-id> [--params JSON]        run one engine command (exec --list: list them, as `commands`)
  run <id> <json> [<id> <json> ...]        run several commands in order
  run --args-file F                        the same, one argument per line of F (no command-line length limit)
+  run --commands FILE|-                    steps from FILE, or standard input for -: a JSON array of
+                                           {\"command\": ID, \"params\": {...}} (or \"id\" for \"command\"), or one
+                                           such object per line (JSON Lines); at most 64 MiB and 100000 steps.
+                                           Repeatable; run after the <id> <json> pairs and --args-file
  props <comp> <layer> [--flat] [--time S] a layer's property tree with paths
  get <comp> <layer> <path> [--time S]     read a property
  set <comp> <layer> <path> <value> [--time S] [--expression E]
@@ -107,7 +112,7 @@ const USAGE: &str = "usage: effectcraft-cli <info|commands|exec|run|props|get|se
         [--jpeg-quality N] [--bitrate KBPS] [--prores PROFILE] [--audio auto|on|off]
         [--profile main|main10] [--level auto|4.1] [--rate-control bitrate|quality] [--video-quality N]
         [--keyint FRAMES] [--webm-codec vp9|av1] [--audio-bitrate KBPS] [--opus-app audio|voice] | --queue
-                                           (formats h264|hevc|av1|prores|webm|png|jpeg|tiff|exr|gif|wav|aiff;
+                                           (formats h264|hevc|av1|prores|webm|png|jpeg|tiff|exr|tga|gif|wav|aiff;
                                           --profile..--keyint: HEVC / AV1, --audio-bitrate/--opus-app: WebM Opus)
                                           a relative --out is relative to the working directory
                                           --progress: progress lines on stderr when it is not a terminal
@@ -151,6 +156,7 @@ const VALUED: &[&str] = &[
    "--depth",
    "--eval",
    "--args-file",
+    "--commands",
    // render
    "--template",
    "--values",
@@ -279,6 +285,9 @@ fn utf8_args(raw: impl IntoIterator<Item = std::ffi::OsString>) -> Result<Vec<St
 }

 fn main() {
+    // Warnings and errors to standard error (`RUST_LOG` overrides), so a GPU that declines
+    // frames or runs out of memory says so instead of silently rendering on the CPU.
+    effectcraft_engine::logging::install_with("warn");
    let raw = match utf8_args(std::env::args_os().skip(1)) {
        Ok(raw) => raw,
        Err(e) => fail_usage(&e),
@@ -334,6 +343,87 @@ impl From<String> for Failure {
    }
 }

+/// Most bytes `run --commands` reads from a file or standard input: the steps are untrusted input.
+const MAX_COMMANDS_BYTES: u64 = 64 * 1024 * 1024;
+/// Most steps one `run --commands` takes.
+const MAX_COMMANDS_STEPS: usize = 100_000;
+
+/// The text of `--commands source`: the file `source`, or standard input for `-`, refused past
+/// [`MAX_COMMANDS_BYTES`]. This reader, [`parse_commands`] and [`command_step`] are ported from
+/// vectorcraft-cli's (storytold/vectorcraft#3630), with a tuple in place of its `Step` enum.
+fn read_commands(source: &str) -> Result<String, String> {
+    use std::io::Read;
+    let mut bytes = vec![];
+    let read = if source == "-" {
+        std::io::stdin().lock().take(MAX_COMMANDS_BYTES + 1).read_to_end(&mut bytes)
+    } else {
+        std::fs::File::open(source).and_then(|f| f.take(MAX_COMMANDS_BYTES + 1).read_to_end(&mut bytes))
+    };
+    read.map_err(|e| format!("--commands {source}: {e}"))?;
+    if bytes.len() as u64 > MAX_COMMANDS_BYTES {
+        return Err(format!("--commands {source}: more than {} MiB of steps", MAX_COMMANDS_BYTES / (1024 * 1024)));
+    }
+    String::from_utf8(bytes).map_err(|_| format!("--commands {source}: not UTF-8 text"))
+}
+
+/// The steps of `--commands source` from its `text`: a JSON array of `{"command": ID, "params":
+/// {…}}` objects (`"id"` may stand for `"command"`), or one such object per line (JSON Lines, blank
+/// lines skipped). `first` is the run's index of the first of them, which an error names with the
+/// entry's place in the text.
+fn parse_commands(source: &str, text: &str, first: usize) -> Result<Vec<(String, Value)>, String> {
+    // Notepad on Windows starts UTF-8 files with a byte order mark.
+    let text = text.strip_prefix('\u{feff}').unwrap_or(text);
+    let too_many = || format!("--commands {source}: more than {MAX_COMMANDS_STEPS} steps");
+    // Each entry with where it is in the text: its line for JSON Lines.
+    let mut entries: Vec<(Option<usize>, Value)> = vec![];
+    if text.trim_start().starts_with('[') {
+        let v: Value = serde_json::from_str(text).map_err(|e| format!("--commands {source}: {e}"))?;
+        let Value::Array(items) = v else { return Err(format!("--commands {source}: not a JSON array")) };
+        if items.len() > MAX_COMMANDS_STEPS {
+            return Err(too_many());
+        }
+        entries.extend(items.into_iter().map(|v| (None, v)));
+    } else {
+        for (n, line) in text.lines().enumerate().filter(|(_, l)| !l.trim().is_empty()) {
+            if entries.len() == MAX_COMMANDS_STEPS {
+                return Err(too_many());
+            }
+            let v = serde_json::from_str(line).map_err(|e| format!("--commands {source}: step {} (line {}): {e}", first + entries.len(), n + 1))?;
+            entries.push((Some(n + 1), v));
+        }
+    }
+    entries
+        .into_iter()
+        .enumerate()
+        .map(|(k, (line, v))| {
+            command_step(v).map_err(|e| {
+                let place = line.map_or_else(|| format!("entry {}", k + 1), |l| format!("line {l}"));
+                format!("--commands {source}: step {} ({place}): {e}", first + k)
+            })
+        })
+        .collect()
+}
+
+/// The command id and params of one `--commands` entry, `{"command": ID, "params": {…}}`.
+fn command_step(v: Value) -> Result<(String, Value), String> {
+    let Value::Object(mut o) = v else { return Err("a step must be an object such as {\"command\": \"comp.new\", \"params\": {}}".into()) };
+    let id = match (o.remove("command"), o.remove("id")) {
+        (Some(Value::String(id)), None) | (None, Some(Value::String(id))) => id,
+        (Some(_), Some(_)) => return Err("give `command` or `id`, not both".into()),
+        (None, None) => return Err("no `command`".into()),
+        _ => return Err("`command` must be a string, a command id".into()),
+    };
+    let params = match o.remove("params") {
+        None | Some(Value::Null) => json!({}),
+        Some(p @ Value::Object(_)) => p,
+        Some(_) => return Err(format!("`params` of {id} must be a JSON object")),
+    };
+    if let Some(key) = o.keys().next() {
+        return Err(format!("unknown key `{key}`: a step has `command` (or `id`) and `params`"));
+    }
+    Ok((id, params))
+}
+
 fn usage_err<T>(m: &str) -> Result<T, Failure> {
    Err(Failure::Usage(m.to_string()))
 }
@@ -524,14 +614,14 @@ fn run(cmd: &str, args: &Args, json_out: bool) -> Result<(), Failure> {
                let text = std::fs::read_to_string(f).map_err(|e| Failure::Usage(format!("--args-file {f}: {e}")))?;
                pairs.extend(text.lines().map(str::trim).filter(|l| !l.is_empty()).map(String::from));
            }
-            if pairs.is_empty() {
-                return usage_err("run needs <command-id> [<json>] pairs");
+            let sources = args.opts("--commands");
+            if pairs.is_empty() && sources.is_empty() {
+                return usage_err("run needs <command-id> [<json>] pairs or --commands FILE|-");
            }
-            let mut b = backend(args, true)?;
-            let mut results = vec![];
+            let mut steps = vec![];
            let mut i = 0;
            while i < pairs.len() {
-                let id = &pairs[i];
+                let id = pairs[i].clone();
                let params = match pairs.get(i + 1).filter(|p| p.trim_start().starts_with('{')) {
                    Some(p) => {
                        i += 1;
@@ -540,9 +630,26 @@ fn run(cmd: &str, args: &Args, json_out: bool) -> Result<(), Failure> {
                    None => json!({}),
                };
                i += 1;
-                let r = b.exec(id, params).map_err(|e| Failure::Error(format!("{id}: {e}")))?;
-                if let Some(e) = failed_render(id, &r) {
-                    return Err(Failure::Error(format!("{id}: {e}")));
+                steps.push((id, params));
+            }
+            if sources.iter().filter(|s| **s == "-").count() > 1 {
+                return usage_err("--commands - is given twice: standard input is read once");
+            }
+            for &source in &sources {
+                let text = read_commands(source).map_err(Failure::Usage)?;
+                steps.extend(parse_commands(source, &text, steps.len()).map_err(Failure::Usage)?);
+            }
+            if steps.is_empty() {
+                return Err(Failure::Usage(format!("--commands {}: no commands", sources.join(", "))));
+            }
+            let mut b = backend(args, true)?;
+            let mut results = vec![];
+            // The step's index closes the message: a generated list repeats ids, and callers match
+            // the leading `<id>: `.
+            for (n, (id, params)) in steps.into_iter().enumerate() {
+                let r = b.exec(&id, params).map_err(|e| Failure::Error(format!("{id}: {e} (step {n})")))?;
+                if let Some(e) = failed_render(&id, &r) {
+                    return Err(Failure::Error(format!("{id}: {e} (step {n})")));
                }
                if !json_out {
                    emit(&r, false);
@@ -783,6 +890,7 @@ fn render(args: &Args, json_out: bool) -> Result<(), Failure> {
            r["outputModuleSummary"].as_str().unwrap_or("")
        );
    }
+    let attempted: std::collections::HashSet<u64> = s.project.render_queue.iter().filter(|i| i.is_queued()).map(|i| i.id).collect();
    s.execute("renderQueue.render", json!({"wait": false})).map_err(err)?;
    let tty = std::io::IsTerminal::is_terminal(&std::io::stderr());
    // `--progress`: one line per update for a program reading stderr (a terminal gets the live line).
@@ -821,7 +929,7 @@ fn render(args: &Args, json_out: bool) -> Result<(), Failure> {
    }
    let mut results = vec![];
    let mut failed = vec![];
-    for it in s.project.render_queue.iter().filter(|i| i.render && i.started.is_some()) {
+    for it in s.project.render_queue.iter().filter(|i| attempted.contains(&i.id)) {
        let name = s.project.item(it.comp).map(|i| i.name.clone()).unwrap_or_else(|| "?".into());
        match &it.status {
            RenderStatus::Done => {
@@ -1189,7 +1297,7 @@ fn adv3d_bench_comp(p: &mut effectcraft_engine::project::Project) -> Option<Item
        set(l, "cameraOptions/highlightGain", Value::Scalar(20.0));
        set(l, "cameraOptions/highlightThreshold", Value::Scalar(200.0));
    });
-    comp.layers = layers;
+    comp.layers = layers.into();
    Some(p.add_item("Advanced 3D (bench)", effectcraft_engine::color::Label::None, None, ItemKind::Comp(comp.into())))
 }

@@ -133,6 +133,78 @@ fn run_reads_arguments_from_a_file() {
    assert!(String::from_utf8_lossy(&out.stderr).contains("--args-file no/such/file.txt"));
 }

+/// Run with `stdin` piped in; returns (exit code, stdout, stderr).
+fn run_with_stdin(args: &[&str], stdin: &str) -> (i32, String, String) {
+    let mut child = bin().args(args).stdin(Stdio::piped()).stdout(Stdio::piped()).stderr(Stdio::piped()).spawn().unwrap();
+    child.stdin.take().unwrap().write_all(stdin.as_bytes()).unwrap();
+    let out = child.wait_with_output().unwrap();
+    (out.status.code().unwrap_or(-1), String::from_utf8_lossy(&out.stdout).into_owned(), String::from_utf8_lossy(&out.stderr).into_owned())
+}
+
+/// `run --commands FILE|-` (#2251) reads `{"command", "params"}` steps from a JSON array or JSON
+/// Lines, from a file or standard input, and runs them as the same positional pairs would: after
+/// the pairs, so a generated list can follow a hand-written prefix. One command whose params are
+/// over Linux's 128 KiB per-argument limit goes through.
+#[test]
+fn run_reads_commands_from_a_file_or_stdin() {
+    let steps = [
+        ("comp.new", json!({"name": "A", "width": 64, "height": 64})),
+        ("layer.newSolid", json!({"width": 8, "height": 8, "name": "One"})),
+        ("layer.newSolid", json!({"width": 8, "height": 8, "name": "Two"})),
+        ("project.summary", json!({})),
+    ];
+    let pairs: Vec<String> = steps.iter().flat_map(|(id, p)| [id.to_string(), p.to_string()]).collect();
+    let pairs: Vec<&str> = pairs.iter().map(String::as_str).collect();
+    let expected = ok_json(&[&["run", "--empty"][..], &pairs[..]].concat());
+    let layers = |v: &Value| v[3]["result"]["items"][0]["layers"].as_u64();
+    assert_eq!(layers(&expected), Some(2), "{expected}");
+
+    let objects: Vec<Value> = steps.iter().map(|(id, p)| json!({"command": id, "params": p})).collect();
+    let array = tmp("commands.json");
+    std::fs::write(&array, serde_json::to_string_pretty(&objects).unwrap()).unwrap();
+    assert_eq!(ok_json(&["run", "--commands", array.to_str().unwrap(), "--empty"]), expected);
+
+    let lines: String = objects.iter().map(|o| format!("{o}\n\n")).collect();
+    let (code, out, err) = run_with_stdin(&["run", "--commands", "-", "--empty", "--json"], &lines);
+    assert_eq!(code, 0, "{err}");
+    assert_eq!(serde_json::from_str::<Value>(&out).unwrap(), expected);
+
+    // Positional pairs first, then the file.
+    let rest = tmp("commands-rest.jsonl");
+    std::fs::write(&rest, objects[1..].iter().map(|o| format!("{o}\n")).collect::<String>()).unwrap();
+    assert_eq!(ok_json(&[&["run", "--empty", "--commands", rest.to_str().unwrap()][..], &pairs[..2]].concat()), expected);
+
+    let name = "n".repeat(140 * 1024);
+    let big = tmp("commands-big.jsonl");
+    std::fs::write(&big, format!("{}\n{}\n", json!({"command": "comp.new", "params": {"name": name}}), json!({"command": "project.summary"}))).unwrap();
+    let v = ok_json(&["run", "--commands", big.to_str().unwrap(), "--empty"]);
+    assert_eq!(v[1]["result"]["items"][0]["name"].as_str().map(str::len), Some(name.len()));
+
+    for (input, args, error) in [
+        ("", &["run", "--commands", "-", "--empty"][..], "--commands -: no commands"),
+        (
+            "{\"command\":\"project.summary\"}\n{\"command\":\"x\",\"param\":{}}\n",
+            &["run", "project.summary", "{}", "--commands", "-", "--empty"],
+            "step 2 (line 2): unknown key `param`",
+        ),
+        ("[{\"command\":\"project.summary\"}, {\"params\":{}}]", &["run", "--commands", "-", "--empty"], "step 1 (entry 2): no `command`"),
+        ("{}", &["run", "--commands", "-", "--commands", "-", "--empty"], "standard input is read once"),
+    ] {
+        let (code, out, err) = run_with_stdin(args, input);
+        assert_eq!(code, 2, "{input:?}: {err}");
+        assert!(err.contains(error), "{input:?}: {err}");
+        assert!(out.is_empty(), "{input:?}: nothing ran");
+    }
+    // An empty list after positional pairs is no error: there is still something to run.
+    let (code, _, err) = run_with_stdin(&["run", "project.summary", "--commands", "-", "--empty"], "");
+    assert_eq!(code, 0, "{err}");
+    // A step that fails when it runs is named by its index too.
+    let (code, out, err) = run_with_stdin(&["run", "--commands", "-", "--empty", "--json"], "{\"command\":\"project.summary\"}\n{\"command\":\"no.such\"}\n");
+    assert_eq!(code, 1, "{err}");
+    let e = serde_json::from_str::<Value>(&out).unwrap()["error"].as_str().map(String::from).unwrap_or_default();
+    assert!(e.starts_with("no.such: ") && e.ends_with(" (step 1)"), "{e}");
+}
+
 #[test]
 fn render_frame_writes_png() {
    let out = tmp("f.png");
@@ -533,6 +605,49 @@ fn a_failed_render_under_run_and_exec_exits_1() {
    assert!(v["error"].as_str().is_some_and(|e| e.starts_with("T: ")), "{v}");
 }

+/// A source refusal happens before encoding and has no started timestamp. It must still
+/// fail the CLI, while the valid queue item finishes and the imported frame stays intact.
+#[test]
+fn a_partly_protected_queue_exits_1_under_render_run_and_exec() {
+    let root = tmp("protected-mixed-queue");
+    let _ = std::fs::remove_dir_all(&root);
+    std::fs::create_dir_all(&root).unwrap();
+    let source = root.join("source_00000.png");
+    image::RgbaImage::from_pixel(4, 4, image::Rgba([40, 80, 120, 255])).save(&source).unwrap();
+    let original = std::fs::read(&source).unwrap();
+    let project = root.join("q.ecproj");
+    let good = root.join("good.gif");
+    let import = json!({"paths": [source]}).to_string();
+    let blocked = json!({"format": "png", "output": root.join("source_[#####].png")}).to_string();
+    let valid = json!({"format": "gif", "output": good}).to_string();
+    ok_json(&[
+        "run",
+        "--empty",
+        "--save-as",
+        project.to_str().unwrap(),
+        "comp.new",
+        r#"{"name":"Main","width":16,"height":16,"frameRate":10,"duration":0.1}"#,
+        "layer.newSolid",
+        "{}",
+        "file.import",
+        &import,
+        "renderQueue.add",
+        &blocked,
+        "renderQueue.add",
+        &valid,
+    ]);
+    let p = project.to_str().unwrap();
+    for args in [vec!["render", "--queue", "--project", p], vec!["run", p, "renderQueue.render", "{}"], vec!["exec", "renderQueue.render", "--project", p]] {
+        std::fs::write(&good, b"previous output").unwrap();
+        let (code, result) = run_json(&args);
+        assert_eq!(code, 1, "{args:?}: {result}");
+        assert!(result["error"].as_str().is_some_and(|e| e.contains("footage") && e.contains("source_00000.png")), "{result}");
+        assert_eq!(std::fs::read(&source).unwrap(), original);
+        assert!(std::fs::read(&good).unwrap().starts_with(b"GIF8"), "the valid item still rendered");
+    }
+    std::fs::remove_dir_all(root).unwrap();
+}
+
 /// `render --bitrate` (#440) targets the bitrate in VP9 WebM.
 #[test]
 fn render_bitrate_applies_to_vp9_webm() {
@@ -37,6 +37,8 @@ js-sys = "0.3"
 web-sys = { version = "0.3", features = [
    "Blob",
    "BlobPropertyBag",
+    "AbortController",
+    "AbortSignal",
    "CssStyleDeclaration",
    "Document",
    "Element",
@@ -51,6 +53,12 @@ web-sys = { version = "0.3", features = [
    "HtmlInputElement",
    "Location",
    "Navigator",
+    "ReadableStream",
+    "ReadableStreamDefaultReader",
+    "Request",
+    "RequestCache",
+    "RequestInit",
+    "Response",
    "Url",
    "UrlSearchParams",
    "Window",
@@ -7,6 +7,23 @@
 //
 // Plain functions only: the Rust side owns the logic.

+// ------------------------------------------------------------------ shortcuts
+
+/// Keep Duplicate on the app canvas instead of also opening the browser's bookmarks.
+/// The physical D key counts on layouts where it types no ASCII letter (e.g. Cyrillic), because
+/// eframe falls back to the key code there; it does not on Dvorak, where it types E.
+/// eframe still receives the key; other chords and HTML inputs keep their browser behavior.
+export function installCanvasShortcuts(canvas) {
+  canvas.addEventListener("keydown", (event) => {
+    if (event.target === canvas && (event.ctrlKey || event.metaKey)
+      && !event.shiftKey && !event.altKey && !event.isComposing
+      && (event.key.toLowerCase() === "d"
+        || (event.code === "KeyD" && !/^[a-z]$/i.test(event.key)))) {
+      event.preventDefault();
+    }
+  }, { capture: true });
+}
+
 // ------------------------------------------------------------------ storage

 const DIR = "effectcraft";
@@ -6,7 +6,8 @@ use std::sync::atomic::{AtomicBool, Ordering};

 use effectcraft_engine::Session;

-use crate::{api, audio, browse, diskcache, files, frames, persist, storage, worker};
+use crate::startup::Startup;
+use crate::{api, audio, browse, config_file, diskcache, files, frames, persist, storage, worker};
 use effectcraft_ui_egui::EffectcraftApp;
 use serde_json::json;
 use wasm_bindgen::prelude::*;
@@ -15,6 +16,8 @@ use wasm_bindgen::prelude::*;
 extern "C" {
    #[wasm_bindgen(js_name = showDeviceLost)]
    fn show_device_lost(message: &str, kept: bool);
+    #[wasm_bindgen(js_name = installCanvasShortcuts)]
+    fn install_canvas_shortcuts(canvas: &web_sys::HtmlCanvasElement);
 }

 /// Work for the UI thread with access to the app (posted by async tasks: picked files…).
@@ -81,8 +84,12 @@ pub(crate) fn open_or_import(app: &mut EffectcraftApp, paths: Vec<String>) {
 /// The eframe app: the shared EffectCraft UI plus the browser host's per-frame duties.
 pub struct WebApp {
    pub app: EffectcraftApp,
-    /// Keep the session snapshot (off with `?empty`).
+    /// Keep the session snapshot (off with `?empty`; off with an explicit `"demo"` startup until
+    /// the user's own work begins, see `demo_start`).
    pub persist: bool,
+    /// Started on the demo by the config: the snapshot stays off, so the demo never replaces the
+    /// last visit's project, until the user opens a project from a file or edits the demo.
+    pub demo_start: bool,
 }

 impl eframe::App for WebApp {
@@ -115,6 +122,11 @@ impl eframe::App for WebApp {
        api::poll_replies();
        // Render Queue outputs written this frame (here or by a worker) → downloads.
        files::flush_downloads();
+        // The user's own work after a demo start is worth keeping too: turn the snapshot on.
+        if self.demo_start && (self.app.session.path.is_some() || self.app.session.is_dirty()) {
+            self.demo_start = false;
+            self.persist = true;
+        }
        // What a reload comes back to.
        if self.persist {
            // The app's monotonic clock: `ctx.input(|i| i.time)` is stale in a logic-only tick.
@@ -204,6 +216,7 @@ pub async fn start(canvas_id: String) -> Result<(), JsValue> {
    effectcraft_ui_egui::i18n::set_system_locales(query_value("lang"), browser.collect());
    let doc = web_sys::window().and_then(|w| w.document()).ok_or("no document")?;
    let canvas: web_sys::HtmlCanvasElement = doc.get_element_by_id(&canvas_id).ok_or("no canvas")?.dyn_into()?;
+    install_canvas_shortcuts(&canvas);
    let empty = query_flag("empty");
    let home = query_flag("home");
    // Browser storage: settings, recent projects, imported media, saved projects, auto-saves and
@@ -220,6 +233,11 @@ pub async fn start(canvas_id: String) -> Result<(), JsValue> {
    };
    api::set_info("storage", json!({"backend": persist::backend(), "entries": stored, "loadMs": t0.elapsed().as_secs_f64() * 1000.0}));
    audio::install_unlock();
+    // `./effectcraft-config.json`: what to open on load.
+    // `?empty` and `?demo` decide by themselves, so they skip the request.
+    let startup = if empty || query_flag("demo") { Startup::default() } else { config_file::startup().await };
+    // An explicit `"demo"` start leaves the saved session alone until the user opens or edits something.
+    let keep_session = !empty && startup.keeps_session();
    browse::restore();
    diskcache::init();
    storage::refresh();
@@ -245,7 +263,7 @@ pub async fn start(canvas_id: String) -> Result<(), JsValue> {
                    // The canvas can't present any more (#225): the page says so over it and
                    // offers a reload, which brings the session back when browser storage keeps it.
                    let lost = gpu_failures.clone();
-                    let kept = !empty && persist::backend() != "memory";
+                    let kept = keep_session && persist::backend() != "memory";
                    rs.device.set_device_lost_callback(move |reason, message| {
                        let message = format!("GPU device lost ({reason:?}): {message}");
                        lost.report(&message, true);
@@ -254,11 +272,14 @@ pub async fn start(canvas_id: String) -> Result<(), JsValue> {
                }
                let mut session = session();
                session.load_settings();
+                // Scripts in Scripts/Startup run before a project opens.
+                let _ = session.execute("file.runStartupScripts", json!({}));
                let recovery = session.begin_recovery();
-                // `?empty`: a blank project; `?demo`: the demo project; otherwise the last visit's
-                // project (the demo on a first visit).
-                let restored = !empty && !query_flag("demo") && persist::restore(&mut session);
-                if !restored && !empty {
+                // `?empty`: a blank project; `?demo`: the demo project; otherwise what the config's
+                // `startup` says (default: the last visit's project, the demo on a first visit).
+                let demo = query_flag("demo");
+                let restored = !empty && !demo && startup.restores() && persist::restore(&mut session);
+                if !restored && !empty && (demo || startup.demo_when_nothing_restored()) {
                    let _ = session.execute("file.openDemoProject", json!({}));
                }
                api::set_info("restored", json!(restored));
@@ -284,7 +305,7 @@ pub async fn start(canvas_id: String) -> Result<(), JsValue> {
                app = app.with_control(rx);
                let backend = cc.wgpu_render_state.as_ref().map(|rs| format!("{:?}", rs.adapter.get_info().backend));
                api::set_info("backend", json!(backend));
-                Ok(Box::new(WebApp { app, persist: !empty }))
+                Ok(Box::new(WebApp { app, persist: keep_session, demo_start: !empty && !keep_session }))
            }),
        )
        .await?;
@@ -0,0 +1,73 @@
+//! `./effectcraft-config.json`, fetched once per page load and shared by whoever reads a key.
+
+use std::cell::RefCell;
+
+use wasm_bindgen::{JsCast, closure::Closure};
+use wasm_bindgen_futures::JsFuture;
+
+use crate::startup::{self, Startup};
+
+/// Longest the request and the body read may take (ms); a stalled server must not hold up start-up.
+const TIMEOUT_MS: i32 = 5_000;
+
+thread_local! {
+    /// `None`: not fetched yet; `Some(None)`: no usable file.
+    static FILE: RefCell<Option<Option<Vec<u8>>>> = const { RefCell::new(None) };
+}
+
+/// The config file's bytes, or `None` when it is missing, too large, unreadable or the request
+/// takes longer than [`TIMEOUT_MS`] (the timer aborts the request and covers the body read).
+async fn fetch() -> Option<Vec<u8>> {
+    let win = web_sys::window()?;
+    let ctl = web_sys::AbortController::new().ok()?;
+    let init = web_sys::RequestInit::new();
+    // Always ask the server: the file is the operator's switch, never a cached copy.
+    init.set_cache(web_sys::RequestCache::NoCache);
+    init.set_signal(Some(&ctl.signal()));
+    let on_timeout = Closure::once(move || ctl.abort());
+    let timer = win.set_timeout_with_callback_and_timeout_and_arguments_0(on_timeout.as_ref().unchecked_ref(), TIMEOUT_MS).ok()?;
+    let out = read(&win, &init).await;
+    win.clear_timeout_with_handle(timer);
+    out
+}
+
+/// Fetch the file and read its body chunk by chunk, giving up as soon as it passes `CONFIG_MAX`.
+async fn read(win: &web_sys::Window, init: &web_sys::RequestInit) -> Option<Vec<u8>> {
+    let req = web_sys::Request::new_with_str_and_init("effectcraft-config.json", init).ok()?;
+    let resp: web_sys::Response = JsFuture::from(win.fetch_with_request(&req)).await.ok()?.dyn_into().ok()?;
+    if resp.status() != 200 {
+        return None;
+    }
+    let reader: web_sys::ReadableStreamDefaultReader = resp.body()?.get_reader().unchecked_into();
+    let mut out = Vec::new();
+    loop {
+        let chunk = JsFuture::from(reader.read()).await.ok()?;
+        if js_sys::Reflect::get(&chunk, &"done".into()).ok()?.as_bool() == Some(true) {
+            return Some(out);
+        }
+        let bytes: js_sys::Uint8Array = js_sys::Reflect::get(&chunk, &"value".into()).ok()?.dyn_into().ok()?;
+        if out.len().saturating_add(bytes.length() as usize) > startup::CONFIG_MAX {
+            // Stop the download: the limit is enforced while reading, not after the whole body arrived.
+            let _ = reader.cancel();
+            return None;
+        }
+        out.extend_from_slice(&bytes.to_vec());
+    }
+}
+
+/// The config file's bytes (`None` when there is none), fetched on the first call.
+pub async fn bytes() -> Option<Vec<u8>> {
+    if let Some(done) = FILE.with(|f| f.borrow().clone()) {
+        return done;
+    }
+    let got = fetch().await;
+    FILE.with(|f| *f.borrow_mut() = Some(got.clone()));
+    got
+}
+
+/// The configured startup behaviour.
+pub async fn startup() -> Startup {
+    let s = bytes().await.map(|b| startup::parse(&b)).unwrap_or_default();
+    log::info!("startup: {s:?}");
+    s
+}
@@ -18,10 +18,11 @@
 //! | cpal audio output | Web Audio: an AudioWorklet fed from the preview mixdown (`audio`) |
 //! | TCP control channel / MCP | `window.effectcraft` JavaScript API (`api`) |
 //!
-//! [`store`] is portable (unit-tested natively); everything else is `wasm32`-only.
+//! [`store`] and [`startup`] are portable (unit-tested natively); everything else is `wasm32`-only.

 #![deny(clippy::unwrap_used, clippy::expect_used, clippy::panic, clippy::unimplemented, clippy::todo, clippy::unreachable)]

+pub mod startup;
 pub mod store;

 #[cfg(target_arch = "wasm32")]
@@ -33,6 +34,8 @@ pub mod audio;
 #[cfg(target_arch = "wasm32")]
 pub mod browse;
 #[cfg(target_arch = "wasm32")]
+pub mod config_file;
+#[cfg(target_arch = "wasm32")]
 pub mod diskcache;
 #[cfg(target_arch = "wasm32")]
 pub mod files;
@@ -0,0 +1,55 @@
+//! The `startup` key of `./effectcraft-config.json`: which project the page opens on load.
+//!
+//! | Value | On load |
+//! |---|---|
+//! | `"last"` (and absent) | the last visit's project; the demo project on a first visit |
+//! | `"empty"` | the last visit's project; a blank project on a first visit, never the demo |
+//! | `"demo"` | the demo project, whatever the last visit left |
+//!
+//! The `?empty` and `?demo` URL flags still win. Anything else (a missing key, another type, an
+//! unknown value, a config that is not JSON) is the default, `"last"`.
+
+use serde_json::Value;
+
+/// What the page opens on load.
+#[derive(Clone, Copy, Debug, Default, PartialEq, Eq)]
+pub enum Startup {
+    #[default]
+    Last,
+    Empty,
+    Demo,
+}
+
+/// The largest config file read (bytes).
+pub const CONFIG_MAX: usize = 64 * 1024;
+
+/// The `startup` key of a config file's bytes.
+pub fn parse(bytes: &[u8]) -> Startup {
+    if bytes.len() > CONFIG_MAX {
+        return Startup::default();
+    }
+    let Ok(v) = serde_json::from_slice::<Value>(bytes) else { return Startup::default() };
+    match v.get("startup").and_then(Value::as_str) {
+        Some("empty") => Startup::Empty,
+        Some("demo") => Startup::Demo,
+        _ => Startup::Last,
+    }
+}
+
+impl Startup {
+    /// Whether the last visit's project is restored (off for the demo).
+    pub fn restores(self) -> bool {
+        self != Startup::Demo
+    }
+
+    /// Whether the session snapshot keeps being saved (off for the demo, so it never replaces the
+    /// project the last visit left).
+    pub fn keeps_session(self) -> bool {
+        self != Startup::Demo
+    }
+
+    /// Whether the demo project opens when nothing was restored (off for a blank start).
+    pub fn demo_when_nothing_restored(self) -> bool {
+        self != Startup::Empty
+    }
+}
@@ -366,6 +366,21 @@ impl ConfigStore for WebConfig {
        v.sort();
        v
    }
+    /// The first name part of the keys under `dir/`.
+    fn list_dirs(&self, dir: &str) -> Vec<String> {
+        let pre = format!("{CONFIG}{}/", dir.trim_end_matches('/'));
+        let mut v: Vec<String> = self
+            .store
+            .lock()
+            .list(&pre)
+            .into_iter()
+            .filter_map(|(k, ..)| k.strip_prefix(&pre)?.split_once('/').map(|(d, _)| d.to_string()))
+            .filter(|d| !d.is_empty())
+            .collect();
+        v.sort();
+        v.dedup();
+        v
+    }
    fn dir(&self) -> Option<PathBuf> {
        Some(PathBuf::from("/"))
    }
@@ -533,6 +548,22 @@ mod tests {
        assert_eq!(s.file("/clip.mp4").as_deref(), Some(&b"abc"[..]));
    }

+    /// Scripts in a subfolder of the Scripts folder (`Tools/Hello.jsx`) are listed, as on the desktop.
+    #[test]
+    fn config_store_lists_folders() {
+        let c = WebConfig::new(store());
+        for name in ["Scripts/Top.jsx", "Scripts/Tools/Hello.jsx", "Scripts/Tools/More.jsx", "Scripts/ScriptUI Panels/Kit/A.jsx"] {
+            c.write(name, "x").unwrap();
+        }
+        assert_eq!(c.list("Scripts"), ["Top.jsx"]);
+        assert_eq!(c.list_dirs("Scripts"), ["ScriptUI Panels", "Tools"]);
+        assert_eq!(c.list_dirs("Scripts/ScriptUI Panels"), ["Kit"]);
+        let mut s = effectcraft_engine::Session { config: Some(Arc::new(c)), ..Default::default() };
+        let list = s.execute("file.scripts.list", serde_json::json!({})).unwrap();
+        let installed: Vec<&str> = list.as_array().unwrap().iter().filter(|e| e["source"] == "installed").filter_map(|e| e["name"].as_str()).collect();
+        assert_eq!(installed, ["Tools/Hello.jsx", "Tools/More.jsx", "Top.jsx", "Kit/A.jsx"]);
+    }
+
    #[test]
    fn config_store_and_file_ops() {
        let s = store();
@@ -0,0 +1 @@
+mod startup_tests;
@@ -0,0 +1,52 @@
+//! The `startup` key of the config file.
+
+use effectcraft_web::startup::{CONFIG_MAX, Startup, parse};
+
+/// The three accepted values parse.
+#[test]
+fn the_three_values() {
+    assert_eq!(parse(br#"{"startup":"empty"}"#), Startup::Empty);
+    assert_eq!(parse(br#"{"startup":"demo"}"#), Startup::Demo);
+    assert_eq!(parse(br#"{"startup":"last"}"#), Startup::Last);
+}
+
+/// A missing key, a wrong type, an unknown value or a non-object file gives `Last`.
+#[test]
+fn absent_or_invalid_is_the_default() {
+    for bytes in
+        [&b"{}"[..], b"", b"not json", b"[]", b"null", br#"{"startup":1}"#, br#"{"startup":"Empty"}"#, br#"{"startup":null}"#, br#"{"startup":["empty"]}"#]
+    {
+        assert_eq!(parse(bytes), Startup::Last, "{:?}", String::from_utf8_lossy(bytes));
+    }
+}
+
+/// Other keys do not hide `startup`.
+#[test]
+fn a_config_with_other_keys_still_has_its_startup() {
+    assert_eq!(parse(br#"{"remote":{"mounts":[]},"startup":"empty"}"#), Startup::Empty);
+    assert_eq!(parse(br#"{"startup":"demo","unknown":{"a":1}}"#), Startup::Demo);
+}
+
+/// A file over `CONFIG_MAX` is ignored.
+#[test]
+fn an_oversized_file_is_the_default() {
+    let mut big = br#"{"startup":"empty","pad":""#.to_vec();
+    big.extend(std::iter::repeat_n(b'x', CONFIG_MAX));
+    big.extend_from_slice(br#""}"#);
+    assert_eq!(parse(&big), Startup::Last);
+}
+
+/// Which project each value restores or opens.
+#[test]
+fn what_each_value_does_on_load() {
+    assert!(Startup::Last.restores() && Startup::Last.demo_when_nothing_restored());
+    assert!(Startup::Empty.restores() && !Startup::Empty.demo_when_nothing_restored());
+    assert!(!Startup::Demo.restores() && Startup::Demo.demo_when_nothing_restored());
+}
+
+/// Only the explicit demo start stops saving the session.
+#[test]
+fn only_the_demo_start_leaves_the_saved_session_alone() {
+    assert!(Startup::Last.keeps_session() && Startup::Empty.keeps_session());
+    assert!(!Startup::Demo.keeps_session());
+}
@@ -8,6 +8,8 @@
 // - A lost WebGPU device: the page says so over the canvas and offers Save Project and Reload;
 //   the reload writes pending changes to browser storage first, and a failed write is reported
 //   instead of reloading (#225).
+// - Duplicate cancels the browser's bookmark action on the app canvas, while still delivering
+//   the key to the app; other chords and HTML inputs keep their browser behavior (#2495).
 // Exits non-zero on failure.
 import assert from "node:assert/strict";
 import { dirname, join } from "node:path";
@@ -58,6 +60,30 @@ globalThis.location = { reload: () => reloads++ };

 const host = await import(pathToFileURL(join(here, "../js/host.js")));

+// #2495: prevent the browser default without swallowing the app's Duplicate key.
+const canvas = new EventTarget();
+const input = new EventTarget();
+host.installCanvasShortcuts(canvas);
+let delivered = 0;
+canvas.addEventListener("keydown", () => delivered++);
+const key = (target, properties) => {
+  const event = new Event("keydown", { cancelable: true });
+  Object.assign(event, { key: "d", ...properties });
+  target.dispatchEvent(event);
+  return event.defaultPrevented;
+};
+assert.equal(key(canvas, { ctrlKey: true }), true);
+assert.equal(key(canvas, { metaKey: true, key: "D" }), true);
+for (const properties of [{}, { ctrlKey: true, shiftKey: true }, { ctrlKey: true, altKey: true }, { ctrlKey: true, isComposing: true }, { ctrlKey: true, key: "r" }]) {
+  assert.equal(key(canvas, properties), false);
+}
+// Non-Latin layouts: the physical D key types "в", and eframe still reads it as D.
+assert.equal(key(canvas, { ctrlKey: true, key: "в", code: "KeyD" }), true);
+// Dvorak: the physical D key types "e", which is not Duplicate.
+assert.equal(key(canvas, { ctrlKey: true, key: "e", code: "KeyD" }), false);
+assert.equal(delivered, 9, "all keys still reach the app");
+assert.equal(key(input, { ctrlKey: true }), false, "an external HTML input keeps its shortcut");
+
 // #226: one readable and one unreadable file.
 const file = (name, read) => ({ name, webkitRelativePath: "", arrayBuffer: read });
 const picked = host.browsePickFiles(false);
@@ -3,7 +3,8 @@
 // `cargo xtask web` fills in the build's file list and version. Every file is precached into a
 // cache named after the version, served cache-first (responses keep the server's headers, so
 // the page stays cross-origin isolated: COOP/COEP), and old versions are dropped once the new
-// one activates. Anything else same-origin is fetched from the network and cached for next time.
+// one activates. Anything else same-origin is fetched from the network and cached for next time,
+// except the config file, which must stay live.
 const VERSION = "__EC_VERSION__";
 const FILES = __EC_FILES__;
 const CACHE = `effectcraft-${VERSION}`;
@@ -30,6 +31,7 @@ self.addEventListener("fetch", (event) => {
  const req = event.request;
  const url = new URL(req.url);
  if (req.method !== "GET" || url.origin !== self.location.origin) return;
+  if (url.pathname.endsWith("/effectcraft-config.json")) return;
  event.respondWith(
    (async () => {
      const cache = await caches.open(CACHE).catch(() => null);
@@ -263,6 +263,9 @@ fn main() -> eframe::Result {
            // Fit the window to its monitor, or put it back where it was (still hidden).
            let saved_window = session.config.as_deref().and_then(window::load);
            let opened = cc.winit_window().map(|w| window::restore(w, saved_window));
+            // Scripts in Scripts/Startup run before a project opens (a failing one is reported in
+            // a toast).
+            let _ = session.execute("file.runStartupScripts", json!({}));
            let recovery = if control_port.is_none() { session.begin_recovery() } else { None };
            let project = files.iter().find(|f| is_project_file(f)).cloned();
            if let Some(p) = project {
@@ -378,9 +381,15 @@ fn main() -> eframe::Result {
 /// instead of eframe's fixed set: an older GPU that can't meet those (Intel HD Graphics 5500,
 /// #198) still opens the app, and the compositor then checks what it needs and falls back to
 /// the CPU when the device can't run it. `backends`: Window Graphics' choice, when it makes one.
+///
+/// The surface is eframe's own default, [`eframe::SurfaceConfig::LOW_LATENCY`]: vsync with one
+/// frame in flight, so a drag or a scrub shows one frame sooner. The bare
+/// `WgpuConfiguration::default()` is `HIGH_THROUGHPUT` instead (two frames in flight, three
+/// drawables on Metal): one more frame of pointer-to-screen lag on every interaction, about 8 ms
+/// at 120 Hz and 17 ms at 60 Hz, and a third 15 MB drawable held for the window.
 fn wgpu_options(backends: Option<eframe::wgpu::Backends>) -> eframe::WgpuConfiguration {
    use eframe::egui_wgpu::WgpuSetup;
-    let mut config = eframe::WgpuConfiguration::default();
+    let mut config = eframe::WgpuConfiguration::default().with_surface_config(eframe::SurfaceConfig::LOW_LATENCY);
    if let WgpuSetup::CreateNew(setup) = &mut config.wgpu_setup {
        if let Some(b) = backends {
            setup.instance_descriptor.backends = b;
@@ -489,6 +498,8 @@ impl eframe::App for Desktop {
        self.launch.exited();
        self.window.save(self.app.session.config.as_deref());
        self.app.on_exit();
+        // Scripts in Scripts/Shutdown run with the project closed.
+        let _ = self.app.session.execute("file.runShutdownScripts", json!({}));
    }

    fn raw_input_hook(&mut self, ctx: &egui::Context, raw_input: &mut egui::RawInput) {
@@ -567,6 +578,19 @@ mod tests {
        assert!(!setup.instance_descriptor.flags.contains(eframe::wgpu::InstanceFlags::VALIDATION_INDIRECT_CALL));
    }

+    /// The window's surface keeps one frame in flight, like eframe's own default, not the two
+    /// of the bare `WgpuConfiguration::default()` (one extra frame of lag on every drag).
+    #[test]
+    fn the_window_surface_is_low_latency() {
+        for backends in [None, Some(eframe::wgpu::Backends::METAL), Some(eframe::wgpu::Backends::GL)] {
+            let surface = super::wgpu_options(backends).surface;
+            assert_eq!(surface, eframe::SurfaceConfig::LOW_LATENCY, "{backends:?}");
+            assert_eq!(surface.desired_maximum_frame_latency, Some(1));
+            assert_eq!(surface.present_mode, eframe::wgpu::PresentMode::AutoVsync);
+        }
+        assert_eq!(super::wgpu_options(None).surface, eframe::NativeOptions::default().wgpu_options.surface, "eframe's default surface");
+    }
+
    /// The window's device never asks for more than the adapter offers (#198).
    #[test]
    fn device_limits_fit_the_adapter() {
@@ -17,11 +17,19 @@
 # To remove your names, delete your entry (or set fields empty) in a PR. The next
 # contributors.py run, and the next build, drop them.

+[people.Krueels]
+sync_github_name = true
+
 [people.echelon]
 real_name = "Brandon Thomas"
 display_name = "Brandon Thomas"
 sync_github_name = false

+[people.lewandowskit]
+real_name = "Tomasz Lewandowski"
+display_name = "Tomasz Lewandowski"
+sync_github_name = false
+
 [people.switch87]
 real_name = "Gert Pellin"
 display_name = "Gert Pellin"
@@ -98,3 +106,11 @@ sync_github_name = false

 [people.ki2pixel]
 display_name = "ki2pixel"
+
+[people.becauseno7]
+real_name = "Shuvra Basak"
+display_name = "Shuvra Basak"
+sync_github_name = false
+
+[people.ashokram-si]
+real_name = "Ashok Ram"
@@ -64,7 +64,7 @@ impl Backend {
        let params = if params.is_null() { json!({}) } else { params };
        if let Some(c) = self.confinement.clone() {
            let lookup = match c.check_command(id, &params)? {
-                Some(crate::confine::Lookup::ProjectFile) => Some((crate::confine::Lookup::ProjectFile, self.run("project.summary", json!({}))?)),
+                Some(l @ (crate::confine::Lookup::ProjectFile | crate::confine::Lookup::QueueDefault)) => Some((l, self.run("project.summary", json!({}))?)),
                Some(crate::confine::Lookup::RenderOutputs) => Some((crate::confine::Lookup::RenderOutputs, self.run("renderQueue.list", json!({}))?)),
                None => None,
            };
@@ -7,7 +7,9 @@
 //! the roots (symbolic links resolved, no `..`), any other absolute path in its parameters too,
 //! and commands that write to a file they are not given (Save, Increment and Save, rendering the
 //! Render Queue) are checked against where they would write. Commands that run code or open
-//! other applications (scripts, Execute File, Reveal in Finder…) are refused while confined.
+//! other applications (scripts, ScriptUI panels and the events that reach them, Execute File,
+//! Reveal in Finder…) are refused while confined, as is granting scripts the file and network
+//! access the user withheld.

 use std::path::{Component, Path, PathBuf};

@@ -28,13 +30,21 @@ pub struct Confinement {
    write: Vec<PathBuf>,
 }

-/// Commands that run code, act outside the project or open other applications.
+/// Commands that run code, act outside the project or open other applications, besides the
+/// commands that run scripts ([`effectcraft_engine::commands::scripts::RUNS_SCRIPTS`]).
 const REFUSED: &[&str] = &[
-    "script.run",
-    "file.runScript",
    "file.installScript",
    "file.installScriptUIPanel",
    "file.uninstallScript",
+    // A ScriptUI panel's script runs when the panel opens, when an event reaches one of its
+    // controls, and when one of its `app.scheduleTask` tasks comes due.
+    "window.scriptPanel",
+    "window.restoreScriptPanels",
+    "script.runTasks",
+    "scriptui.click",
+    "scriptui.set",
+    "scriptui.mouse",
+    "scriptui.close",
    "file.executeFile",
    "file.revealInFinder",
    "layer.openSource",
@@ -64,10 +74,29 @@ const READS: &[(&str, &[&str])] = &[
    ("effect.plugins.load", &["path", "folder"]),
    ("mediaBrowser.go", &["path"]),
    ("mediaBrowser.addFavorite", &["path"]),
+    // #1243: these read the files they are given but were missing, so a relative path went
+    // unchecked.
+    ("essential.templateInfo", &["path"]),
+    ("file.importProject", &["path"]),
+    ("file.watchFolder.poll", &["folder"]),
+    ("footage.relink", &["path"]),
+    ("layer.newModel", &["path"]),
+    ("mediaBrowser.fileInfo", &["path"]),
+    ("mediaBrowser.list", &["path"]),
+    ("mediaBrowser.import", &["paths"]),
+    ("mediaBrowser.removeFavorite", &["path"]),
+    ("face.model.install", &["path"]),
+    ("roto.model.install", &["path"]),
+    // Reads the template at `path`; what it writes is in `MIXED_WRITES`.
+    ("templates.create", &["path"]),
 ];

+/// Commands that read some parameters (listed in [`READS`]) and write others.
+const MIXED_WRITES: &[(&str, &[&str])] = &[("templates.create", &["projectPath", "footageDir"])];
+
 /// Commands that write files named by these parameters.
 const WRITES: &[(&str, &[&str])] = &[
+    ("camera.exportBlender", &["path"]),
    ("file.save", &["path"]),
    ("file.saveAs", &["path"]),
    ("file.saveCopy", &["path"]),
@@ -84,6 +113,9 @@ const WRITES: &[(&str, &[&str])] = &[
    ("essential.exportTemplate", &["path"]),
    ("shortcuts.export", &["path"]),
    ("renderQueue.add", &["output", "path"]),
+    ("file.exportTimeline", &["path"]),
+    // `path` / `output` may also be a file-name template, as for render.preRender.
+    ("file.createProxy", &["path", "output"]),
 ];

 /// Commands that write where they are not told: the project's file, the Render Queue's outputs.
@@ -96,6 +128,9 @@ pub enum Lookup {
    ProjectFile,
    /// Every output of the queued Render Queue items (`renderQueue.list`).
    RenderOutputs,
+    /// Whether the open project has a file (`project.summary` → `path`): a Render Queue item
+    /// added without `output` writes beside it, or to the home folder before the first save.
+    QueueDefault,
 }

 impl Confinement {
@@ -135,16 +170,26 @@ impl Confinement {
    /// Check engine command `id` with `params` before it runs. Returns what must still be looked
    /// up and passed to [`Confinement::check_lookup`] for commands that write implicitly.
    pub fn check_command(&self, id: &str, params: &Value) -> Result<Option<Lookup>> {
-        if REFUSED.contains(&id) {
+        if REFUSED.contains(&id) || effectcraft_engine::commands::scripts::RUNS_SCRIPTS.contains(&id) {
            return Err(Error::BadArgs(format!("`{id}` is not available while file access is confined (--automation-read-root/--automation-write-root)")));
        }
+        // Scripts can't grant themselves the access the user withheld
+        // (`effectcraft_engine::prefs::Scripting::same_permissions`), and neither may a confined
+        // agent: `prefs.set` saves the settings file, so a script run long after this session
+        // would still have it. (`prefs.reset` only puts the defaults back, which grant nothing.)
+        if id == "prefs.set" && prefs_keys(params).iter().any(|k| is_scripting_pref(k)) {
+            return Err(Error::BadArgs(
+                "`prefs.set`: the Scripting settings decide what a script may do, so they can't be changed while file access is confined".into(),
+            ));
+        }
        if id == "engine.batch" {
            for step in params.get("steps").and_then(Value::as_array).into_iter().flatten() {
                let Some(inner) = step.get("command").or_else(|| step.get("id")).and_then(Value::as_str) else { continue };
                let inner_params = step.get("params").cloned().unwrap_or(Value::Null);
                let named = keys_of(READS, inner).or_else(|| keys_of(WRITES, inner)).unwrap_or(&[]);
+                let mixed = keys_of(MIXED_WRITES, inner).unwrap_or(&[]);
                // A step's `$N` reference is resolved only as the batch runs: never for a file.
-                if named.iter().filter_map(|k| inner_params.get(*k)).any(has_reference) {
+                if named.iter().chain(mixed).filter_map(|k| inner_params.get(*k)).any(has_reference) {
                    return Err(Error::BadArgs(format!("`{inner}` in a batch: file paths can't be `$N` references while file access is confined")));
                }
                if self.check_command(inner, &inner_params)?.is_some() {
@@ -170,7 +215,7 @@ impl Confinement {
            for p in paths {
                // A Render Queue output may name a template instead of a file.
                match p.as_str() {
-                    Some(s) if id == "render.preRender" && !looks_like_path(s) => {}
+                    Some(s) if matches!(id, "render.preRender" | "file.createProxy") && !looks_like_path(s) => {}
                    Some(s) => {
                        self.check(s, access)?;
                    }
@@ -178,9 +223,18 @@ impl Confinement {
                }
            }
        }
+        // Parameters of a reading command that it writes to.
+        let mixed = keys_of(MIXED_WRITES, id).unwrap_or(&[]);
+        for key in mixed {
+            if let Some(p) = params.get(*key).filter(|v| !v.is_null()) {
+                let p = p.as_str().ok_or_else(|| Error::BadArgs(format!("`{id}`: `{key}` must be a path")))?;
+                self.check(p, Access::Write)?;
+            }
+        }
        // Any other absolute path the command is given.
+        let named: Vec<&str> = named.iter().chain(mixed).copied().collect();
        let mut other = vec![];
-        absolute_strings(params, named, &mut other);
+        absolute_strings(params, &named, &mut other);
        for s in other {
            self.check(&s, access)?;
        }
@@ -188,6 +242,10 @@ impl Confinement {
        if matches!(id, "file.openRecent" | "file.importRecent" | "anim.applyRecentPreset") && !given {
            return Err(Error::BadArgs(format!("`{id}`: give `path` while file access is confined")));
        }
+        // Without `output`, an unsaved project's item would write to the home folder (#2479).
+        if id == "renderQueue.add" && !given {
+            return Ok(Some(Lookup::QueueDefault));
+        }
        if IMPLICIT_WRITES.contains(&id) && !(given && id == "file.save") {
            return Ok(Some(if id == "file.save" || id == "file.incrementAndSave" { Lookup::ProjectFile } else { Lookup::RenderOutputs }));
        }
@@ -202,6 +260,13 @@ impl Confinement {
                Some(p) => self.check(p, Access::Write).map(drop),
                None => Err(Error::BadArgs("the project has no file yet: give `path` (Save As) inside an automation write root".into())),
            },
+            // A saved project's default output sits beside it, and rendering checks it then.
+            Lookup::QueueDefault => match found.get("path").and_then(Value::as_str) {
+                Some(_) => Ok(()),
+                None => Err(Error::BadArgs(
+                    "`renderQueue.add`: the project has no file yet, so the default output would go to the home folder: give `output` inside an automation write root".into(),
+                )),
+            },
            Lookup::RenderOutputs => {
                let items = found.get("items").or(Some(found)).and_then(Value::as_array).cloned().unwrap_or_default();
                for it in items.iter().filter(|it| it.get("render").and_then(Value::as_bool) != Some(false)) {
@@ -218,6 +283,22 @@ impl Confinement {
    }
 }

+/// Whether a `prefs.set` key reaches the Scripting page. `Prefs::set` turns the key into a JSON
+/// pointer (`key.replace('.', "/")`), so `scripting/allowScriptsWriteFiles` resolves as well as
+/// the dotted spelling, and the page on its own replaces every setting on it.
+fn is_scripting_pref(key: &str) -> bool {
+    key.split(['.', '/']).next().is_some_and(|page| page.eq_ignore_ascii_case("scripting"))
+}
+
+/// The settings `prefs.set` is given: `key`, and the keys of `values`.
+fn prefs_keys(params: &Value) -> Vec<&str> {
+    let mut keys: Vec<&str> = params.get("key").and_then(Value::as_str).into_iter().collect();
+    if let Some(Value::Object(m)) = params.get("values") {
+        keys.extend(m.keys().map(String::as_str));
+    }
+    keys
+}
+
 fn keys_of(table: &[(&str, &'static [&'static str])], id: &str) -> Option<&'static [&'static str]> {
    table.iter().find(|(c, _)| *c == id).map(|(_, k)| *k)
 }
@@ -274,3 +355,115 @@ fn resolve(p: &Path) -> Option<PathBuf> {
        at = at.parent()?;
    }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    /// Commands whose parameters are named like files but aren't: property paths
+    /// (`path|prop`), project folders, layers to track or target.
+    const NOT_FILES: &[&str] = &[
+        "camera.createFromSolve",
+        "edit.label",
+        "edit.pasteReversedKeyframes",
+        "effect.editDropdown",
+        "essential.addProperty",
+        "essential.canAdd",
+        "essential.linkProperty",
+        "essential.unlinkProperty",
+        "keys.paste",
+        "keys.set",
+        "keys.setEase",
+        "keys.setSpatialTangents",
+        "paths.nullsFollowPoints",
+        "paths.pointsFollowNulls",
+        "paths.tracePath",
+        "project.move",
+        "prop.addKey",
+        "prop.convertExpressionToKeyframes",
+        "prop.deselect",
+        "prop.editGradient",
+        "prop.get",
+        "prop.pickWhip",
+        "prop.reset",
+        "prop.select",
+        "prop.set",
+        "prop.setExpression",
+        "prop.toggleAnimation",
+        "prop.toggleKey",
+        "track.new",
+        "track.property",
+        "track.setTarget",
+    ];
+
+    /// Every engine command with a parameter named like a file is classified, so a new one
+    /// can't silently skip confinement (#1243): it reads or writes the files it is given, is
+    /// refused, writes where it isn't told (checked by a lookup), sets Render Queue outputs
+    /// (checked when the queue renders), or is listed in `NOT_FILES`.
+    #[test]
+    fn every_command_with_file_parameters_is_classified() {
+        const FILE_KEYS: &[&str] =
+            &["path", "paths", "folder", "file", "files", "dir", "directory", "output", "outputs", "source", "target", "projectPath", "footageDir"];
+        let mut missing = vec![];
+        for spec in effectcraft_engine::command_specs() {
+            let Some(params) = effectcraft_engine::commands::accepted_params(spec.params) else { continue };
+            let id = spec.id;
+            let classified = keys_of(READS, id).is_some()
+                || keys_of(WRITES, id).is_some()
+                || REFUSED.contains(&id)
+                || effectcraft_engine::commands::scripts::RUNS_SCRIPTS.contains(&id)
+                || IMPLICIT_WRITES.contains(&id)
+                || id.starts_with("renderQueue.")
+                || id == "render.addOutputModule"
+                || NOT_FILES.contains(&id);
+            if params.iter().any(|p| FILE_KEYS.contains(&p.as_str())) && !classified {
+                missing.push(format!("{id} {}", spec.params));
+            }
+        }
+        assert!(missing.is_empty(), "add these to READS / WRITES / REFUSED or NOT_FILES:\n{}", missing.join("\n"));
+        // And every listed command exists.
+        for id in READS.iter().chain(WRITES).chain(MIXED_WRITES).map(|(c, _)| *c).chain(NOT_FILES.iter().copied()) {
+            assert!(effectcraft_engine::command_specs().iter().any(|s| s.id == id), "{id} is not a command");
+        }
+    }
+
+    #[test]
+    fn relative_and_outside_paths_of_newly_listed_commands_are_refused() {
+        let base = std::env::temp_dir().join(format!("ec-confine-1243-{}", std::process::id()));
+        let _ = std::fs::remove_dir_all(&base);
+        let (read, write, outside) = (base.join("in"), base.join("out"), base.join("elsewhere"));
+        for d in [&read, &write, &outside] {
+            std::fs::create_dir_all(d).unwrap();
+        }
+        let c = Confinement::new(std::slice::from_ref(&read), std::slice::from_ref(&write)).unwrap();
+        let p = |d: &std::path::Path, f: &str| d.join(f).to_string_lossy().into_owned();
+        let up = format!("{}/../elsewhere/t.ectemplate", read.display());
+        for (id, key) in [
+            ("essential.templateInfo", "path"),
+            ("file.importProject", "path"),
+            ("footage.relink", "path"),
+            ("layer.newModel", "path"),
+            ("mediaBrowser.fileInfo", "path"),
+            ("mediaBrowser.list", "path"),
+            ("face.model.install", "path"),
+            ("templates.create", "path"),
+        ] {
+            for bad in ["t.ectemplate".to_string(), "../elsewhere/t.ectemplate".to_string(), up.clone(), p(&outside, "t.ectemplate")] {
+                assert!(c.check_command(id, &serde_json::json!({key: bad})).is_err(), "{id} {key}={bad}");
+            }
+            assert!(c.check_command(id, &serde_json::json!({key: p(&read, "t.ectemplate")})).is_ok(), "{id} in a read root");
+        }
+        // Batched too.
+        let steps = serde_json::json!({"steps": [{"command": "essential.templateInfo", "params": {"path": "t.ectemplate"}}]});
+        assert!(c.check_command("engine.batch", &steps).is_err());
+        // Writes: into a write root only.
+        assert!(c.check_command("file.exportTimeline", &serde_json::json!({"path": p(&read, "cut.xml")})).is_err());
+        assert!(c.check_command("file.exportTimeline", &serde_json::json!({"path": p(&write, "cut.xml")})).is_ok());
+        let create = |project: String| serde_json::json!({"path": p(&read, "t.ectemplate"), "projectPath": project});
+        assert!(c.check_command("templates.create", &create(p(&read, "new.ecproj"))).is_err(), "templates.create writes projectPath");
+        assert!(c.check_command("templates.create", &create(p(&write, "new.ecproj"))).is_ok());
+        assert!(c.check_command("file.createProxy", &serde_json::json!({"output": "[compName]_proxy"})).is_ok(), "a template name");
+        assert!(c.check_command("file.createProxy", &serde_json::json!({"output": p(&outside, "proxy.mov")})).is_err());
+        let _ = std::fs::remove_dir_all(&base);
+    }
+}
@@ -57,6 +57,50 @@ fn property_group_error_points_to_layer_inspection() {
    assert!(call_json(&mut s, "get_property", json!({"layer": l, "path": "geometryOptions/extrusionDepth"}))["value"].is_number());
 }

+/// Enum properties list their values and labels, so a client can set one without guessing (#2085).
+#[test]
+fn enum_properties_list_their_options() {
+    let mut s = server();
+    call_json(&mut s, "execute_command", json!({"command": "comp.new", "params": {"name": "probe"}}));
+    call_json(&mut s, "execute_command", json!({"command": "layer.newText", "params": {"name": "T", "text": "Hello"}}));
+    call_json(&mut s, "execute_command", json!({"command": "layer.addTextAnimator", "params": {"layer": "T", "properties": ["opacity"], "name": "A"}}));
+    let path = "text/animators/animator/selectors/rangeSelector/advanced/shape";
+    let shapes = ["Square", "Ramp Up", "Ramp Down", "Triangle", "Round", "Smooth"];
+    let expected = json!(shapes.iter().enumerate().map(|(value, label)| json!({"value": value, "label": label})).collect::<Vec<_>>());
+
+    let p = call_json(&mut s, "get_property", json!({"layer": "T", "path": path}));
+    assert_eq!(p["type"], "enum");
+    assert_eq!(p["options"], expected, "{p}");
+    let opacity = call_json(&mut s, "get_property", json!({"layer": "T", "path": "transform/opacity"}));
+    assert!(opacity.get("options").is_none(), "{opacity}");
+
+    fn find<'a>(node: &'a Value, path: &str) -> Option<&'a Value> {
+        if node["path"] == path {
+            return Some(node);
+        }
+        node["children"].as_array()?.iter().find_map(|c| find(c, path))
+    }
+    let tree = call_json(&mut s, "get_layer", json!({"layer": "T"}));
+    let node = find(&tree["properties"], path).unwrap_or_else(|| panic!("{tree}"));
+    assert_eq!(node["options"], expected);
+    assert!(find(&tree["properties"], "transform/opacity").unwrap()["options"].is_null());
+
+    let flat = call_json(&mut s, "get_layer", json!({"layer": "T", "flat": true}));
+    let props = flat["properties"].as_array().unwrap();
+    assert_eq!(props.iter().find(|p| p["path"] == path).unwrap()["options"], expected);
+    assert!(props.iter().find(|p| p["path"] == "transform/opacity").unwrap().get("options").is_none());
+
+    // Path Options ▸ Path offers None and the layer's masks, as the Timeline does.
+    for _ in 0..2 {
+        call_json(&mut s, "execute_command", json!({"command": "mask.new", "params": {"layer": "T", "vertices": [[0, 0], [40, 0], [40, 40]], "closed": true}}));
+    }
+    let masks = json!([{"value": 0, "label": "None"}, {"value": 1, "label": "Mask 1"}, {"value": 2, "label": "Mask 2"}]);
+    let p = call_json(&mut s, "get_property", json!({"layer": "T", "path": "text/pathOptions/path"}));
+    assert_eq!(p["options"], masks, "{p}");
+    let tree = call_json(&mut s, "get_layer", json!({"layer": "T"}));
+    assert_eq!(find(&tree["properties"], "text/pathOptions/path").unwrap_or_else(|| panic!("{tree}"))["options"], masks);
+}
+
 #[test]
 fn initialize_and_list_tools() {
    let mut s = server();
@@ -491,6 +535,8 @@ fn bridge_forwards_to_control_channel() {

    call_json(&mut s, "execute_command", json!({"command": "comp.new", "params": {"name": "B", "width": 64, "height": 64}}));
    assert_eq!(call_json(&mut s, "get_comp", json!({}))["name"], "B");
+    let cmds = call_json(&mut s, "list_commands", json!({"filter": "layer.newSolid", "compact": true}));
+    assert!(cmds.as_array().unwrap().contains(&json!({"id": "layer.newSolid", "label": "Solid..."})), "{cmds}");

    let (c, err) = call(&mut s, "render_frame", json!({}));
    assert!(!err, "{c:?}");
@@ -738,6 +784,40 @@ fn every_engine_command_is_reachable_over_mcp() {
    }
 }

+/// `compact: true` shrinks the listings for MCP clients' tool-result limits (#2020): commands with
+/// only `id` and `label`, effects with only `id`, `name` and `category`.
+#[test]
+fn compact_listings_keep_only_ids_and_names() {
+    let mut s = server();
+    let cmds = call_json(&mut s, "list_commands", json!({"filter": "layer.new", "compact": true}));
+    assert!(cmds.as_array().unwrap().contains(&json!({"id": "layer.newSolid", "label": "Solid..."})), "{cmds}");
+    let fx = call_json(&mut s, "list_effects", json!({"filter": "gaussian", "compact": true}));
+    assert!(fx.as_array().unwrap().contains(&json!({"id": "ec.blur.gaussian", "name": "Gaussian Blur", "category": "Blur & Sharpen"})), "{fx}");
+    // Each compact listing is the full one with the same arguments, entry for entry; `compact`
+    // wins over `schemas`.
+    let check = |s: &mut McpServer, tool: &str, args: Value, keys: &[&str]| {
+        let full = call_json(s, tool, args.clone());
+        let want: Value = full.as_array().unwrap().iter().map(|e| Value::Object(keys.iter().map(|&k| (k.to_string(), e[k].clone())).collect())).collect();
+        let mut compact = args.clone();
+        compact["compact"] = json!(true);
+        assert_eq!(call_json(s, tool, compact), want, "{tool} {args}");
+    };
+    for args in [json!({}), json!({"filter": "layer.new"}), json!({"enabled_only": true}), json!({"schemas": true})] {
+        check(&mut s, "list_commands", args.clone(), &["id", "label"]);
+        check(&mut s, "command_list", args, &["id", "label"]);
+    }
+    check(&mut s, "list_effects", json!({}), &["id", "name", "category"]);
+    check(&mut s, "list_effects", json!({"filter": "gaussian"}), &["id", "name", "category"]);
+    // `compact: false` is the default listing, byte for byte; `compact: true` is a fraction of it.
+    let text = |s: &mut McpServer, tool: &str, args: Value| call(s, tool, args).0[0]["text"].as_str().unwrap().to_string();
+    for (tool, ratio) in [("list_commands", 2), ("list_effects", 10)] {
+        let full = text(&mut s, tool, json!({}));
+        assert_eq!(text(&mut s, tool, json!({"compact": false})), full, "{tool}");
+        let compact = text(&mut s, tool, json!({"compact": true})).len();
+        assert!(compact * ratio < full.len(), "{tool}: {compact} of {} bytes", full.len());
+    }
+}
+
 #[test]
 fn high_level_tools_add_effect_and_report_state() {
    let mut s = server();
@@ -1336,6 +1416,12 @@ fn automation_roots_confine_file_access() {
        assert!(err, "{name} {args} should be refused: {c:?}");
        c[0]["text"].as_str().unwrap_or_default().to_string()
    };
+    // #2479: an unsaved project's queue item without `output` would write to the home folder.
+    call_json(&mut s, "execute_command", json!({"command": "comp.new", "params": {"name": "Unsaved", "width": 64, "height": 64}}));
+    let msg = denied(&mut s, "execute_command", json!({"command": "renderQueue.add", "params": {"comp": "Unsaved"}}));
+    assert!(msg.contains("home folder") && msg.contains("give `output`"), "{msg}");
+    call_json(&mut s, "execute_command", json!({"command": "renderQueue.add", "params": {"comp": "Unsaved", "output": p(&write, "unsaved.mp4")}}));
+    call_json(&mut s, "execute_command", json!({"command": "renderQueue.remove"}));
    // Reading: inside a read root, not outside.
    call_json(&mut s, "open_project", json!({"path": p(&read, "source.ecproj")}));
    let msg = denied(&mut s, "open_project", json!({"path": p(&outside, "free.ecproj")}));
@@ -1376,7 +1462,103 @@ fn automation_roots_confine_file_access() {
    // Scripts can read and write anything: refused.
    denied(&mut s, "run_script", json!({"code": "1 + 1"}));
    denied(&mut s, "execute_command", json!({"command": "file.runScript", "params": {"path": p(&read, "x.jsx")}}));
+    for (id, params) in [
+        ("file.runStartupScripts", json!({})),
+        ("file.runShutdownScripts", json!({})),
+        // ScriptUI panels run their script when they open.
+        ("window.scriptPanel", json!({"name": "Layer Tools.jsx"})),
+        ("window.restoreScriptPanels", json!({})),
+    ] {
+        let msg = denied(&mut s, "execute_command", json!({"command": id, "params": params}));
+        assert!(msg.contains("not available while file access is confined"), "{id}: {msg}");
+        let msg = denied(&mut s, "batch", json!({"steps": [{"command": id, "params": params}]}));
+        assert!(msg.contains("not available while file access is confined"), "{id}: {msg}");
+    }
    // Writes to the files the agent named: none outside.
    assert_eq!(std::fs::read_dir(&outside).unwrap().count(), 1, "only the unconfined save");
    let _ = std::fs::remove_dir_all(&base);
 }
+
+/// #2131 (audit F-11, "Running code"): `script.run` and the Scripts menu are refused while file
+/// access is confined, but a ScriptUI panel's script runs just as freely — when the panel opens,
+/// when an event reaches one of its controls, or when one of its tasks comes due — and
+/// `prefs.set` could grant every script run afterwards the file and network access the user
+/// withheld, in the settings file, long after the session. All of that is refused too.
+#[test]
+fn automation_roots_refuse_running_script_code() {
+    use crate::confine::Confinement;
+    let base = std::env::temp_dir().join(format!("ec-mcp-scripts-{}", std::process::id()));
+    let _ = std::fs::remove_dir_all(&base);
+    std::fs::create_dir_all(&base).unwrap();
+    let mut s = server();
+    s.backend().confine(Confinement::new(&[], std::slice::from_ref(&base)).unwrap());
+    let refused = |s: &mut McpServer, name: &str, args: Value| {
+        let (c, err) = call(s, name, args.clone());
+        assert!(err, "{name} {args} should be refused: {c:?}");
+        c[0]["text"].as_str().unwrap_or_default().to_string()
+    };
+    // Every way a script's code starts.
+    for (command, params) in [
+        ("window.scriptPanel", json!({"name": "Layer Tools.jsx"})),
+        ("window.restoreScriptPanels", json!({})),
+        ("script.runTasks", json!({})),
+        ("scriptui.click", json!({"window": 1, "widget": 2})),
+        ("scriptui.set", json!({"window": 1, "widget": 2, "value": 1})),
+        ("scriptui.mouse", json!({"window": 1, "widget": 2, "type": "click"})),
+        ("scriptui.close", json!({"window": 1})),
+    ] {
+        let msg = refused(&mut s, "execute_command", json!({"command": command, "params": params}));
+        assert!(msg.contains("not available while file access is confined"), "`{command}`: {msg}");
+    }
+    // Including as a batch step.
+    let msg = refused(&mut s, "batch", json!({"steps": [{"command": "window.scriptPanel", "params": {"name": "x.jsx"}}]}));
+    assert!(msg.contains("not available while file access is confined"), "{msg}");
+    // What scripts may do stays as the user left it, by either spelling of the setting.
+    for params in [
+        json!({"key": "scripting.allowScriptsWriteFiles", "value": true}),
+        json!({"key": "scripting.allow_scripts_write_files", "value": true}),
+        json!({"values": {"scripting.warnExecutingFiles": false}}),
+        json!({"values": {"general.showToolTips": false, "scripting.enableJsDebugger": true}}),
+        // `Prefs::set` makes a JSON pointer of the key, so this spelling resolves too…
+        json!({"key": "scripting/allowScriptsWriteFiles", "value": true}),
+        // …and the page on its own replaces every setting on it.
+        json!({"key": "scripting", "value": {"allowScriptsWriteFiles": true}}),
+        json!({"values": {"scripting": {"warnExecutingFiles": false}}}),
+    ] {
+        let msg = refused(&mut s, "execute_command", json!({"command": "prefs.set", "params": params}));
+        assert!(msg.contains("what a script may do"), "{msg}");
+    }
+    let got = call_json(&mut s, "execute_command", json!({"command": "prefs.get", "params": {"key": "scripting.allowScriptsWriteFiles"}}));
+    assert_eq!(got, json!(false), "{got}");
+    // Other settings, and looking at the script windows, still work.
+    call_json(&mut s, "execute_command", json!({"command": "prefs.set", "params": {"key": "general.showToolTips", "value": false}}));
+    call_json(&mut s, "execute_command", json!({"command": "scriptui.list"}));
+    let _ = std::fs::remove_dir_all(&base);
+}
+
+#[test]
+fn blender_export_requires_an_absolute_path_in_a_write_root() {
+    use crate::confine::Confinement;
+    let base = std::env::temp_dir().join(format!("ec-blender-confine-{}", std::process::id()));
+    let (read, write) = (base.join("read"), base.join("write"));
+    for dir in [&read, &write] {
+        std::fs::create_dir_all(dir).unwrap();
+    }
+    let confinement = Confinement::new(std::slice::from_ref(&read), std::slice::from_ref(&write)).unwrap();
+    let check = |path: &std::path::Path| confinement.check_command("camera.exportBlender", &json!({"path": path}));
+    assert_eq!(check(&write.join("scene.py")).unwrap(), None);
+    for path in [read.join("scene.py"), base.join("outside.py"), write.join("../read/scene.py")] {
+        assert!(check(&path).is_err(), "must deny {}", path.display());
+    }
+    for path in ["scene.py", "./scene.py", "write/scene.py", "../scene.py"] {
+        let error = check(std::path::Path::new(path)).unwrap_err().to_string();
+        assert!(error.contains("give an absolute path"), "{path}: {error}");
+    }
+    let read_only = Confinement::new(std::slice::from_ref(&write), &[]).unwrap();
+    assert!(read_only.check_command("camera.exportBlender", &json!({"path": write.join("scene.py")})).is_err());
+    for path in [json!(read.join("scene.py")), json!("scene.py"), json!("$1.path")] {
+        let batch = json!({"steps": [{"command": "camera.exportBlender", "params": {"path": path}}]});
+        assert!(confinement.check_command("engine.batch", &batch).is_err());
+    }
+    std::fs::remove_dir_all(&base).unwrap();
+}
@@ -175,16 +175,21 @@ fn params_of(v: Option<&Value>) -> Result<Value> {

 // ------------------------------------------------------------------ engine tools

+/// `list_commands` tool: the engine command list, minus empty fields; with `compact`, only `id` and `label`.
 fn list_commands(b: &mut Backend, a: &Value) -> Result<Reply> {
-    let schemas = get(a, "schemas").and_then(Value::as_bool).unwrap_or(false).then_some(json!(true));
+    let compact = get(a, "compact").and_then(Value::as_bool).unwrap_or(false);
+    let schemas = (!compact && get(a, "schemas").and_then(Value::as_bool).unwrap_or(false)).then_some(json!(true));
    let r = b.exec("command.list", obj(&[("filter", get(a, "filter")), ("enabledOnly", get(a, "enabled_only")), ("schemas", schemas.as_ref())]))?;
-    // Drop empty fields to keep the listing compact.
    let list: Vec<Value> = r
        .as_array()
        .cloned()
        .unwrap_or_default()
        .into_iter()
        .map(|mut c| {
+            if compact {
+                return json!({"id": c["id"], "label": c["label"]});
+            }
+            // Drop empty fields.
            if let Some(o) = c.as_object_mut() {
                o.retain(|_, v| !(v.is_null() || v.as_array().is_some_and(Vec::is_empty) || v.as_str() == Some("{}")));
            }
@@ -205,8 +210,13 @@ fn describe_command(b: &mut Backend, a: &Value) -> Result<Reply> {
    json_reply(b.exec("command.describe", json!({"command": id}))?)
 }

+/// `list_effects` tool: the effect registry; with `compact`, only `id`, `name` and `category`.
 fn list_effects(b: &mut Backend, a: &Value) -> Result<Reply> {
-    json_reply(b.exec("effect.list", obj(&[("filter", get(a, "filter"))]))?)
+    let mut r = b.exec("effect.list", obj(&[("filter", get(a, "filter"))]))?;
+    if get(a, "compact").and_then(Value::as_bool).unwrap_or(false) {
+        r = r.as_array().into_iter().flatten().map(|e| json!({"id": e["id"], "name": e["name"], "category": e["category"]})).collect();
+    }
+    json_reply(r)
 }

 fn list_fonts(b: &mut Backend, a: &Value) -> Result<Reply> {
@@ -275,7 +285,7 @@ fn get_comp(b: &mut Backend, a: &Value) -> Result<Reply> {
    json_reply(b.exec("comp.info", obj(&[("comp", get(a, "comp"))]))?)
 }

-/// Flatten a `layer.tree` property tree into `[{path, type, value, keys?, expression?}]`.
+/// Flatten a `layer.tree` property tree into `[{path, type, value, keys?, expression?, options?}]`.
 fn flatten(node: &Value, out: &mut Vec<Value>) {
    // A group cut off by `depth` stays visible (instead of vanishing from the flat list).
    if node.get("truncated").and_then(Value::as_bool) == Some(true) {
@@ -292,6 +302,9 @@ fn flatten(node: &Value, out: &mut Vec<Value>) {
            if let Some(e) = node.get("expression") {
                o["expression"] = e.clone();
            }
+            if let Some(opts) = node.get("options") {
+                o["options"] = opts.clone();
+            }
            out.push(o);
        }
    }
@@ -542,14 +555,15 @@ fn control(b: &mut Backend, a: &Value) -> Result<Reply> {
 static TOOLS: &[ToolDef] = &[
    ToolDef {
        name: "list_commands",
-        description: "List engine commands: id, label, menu path, shortcut, `params` doc (e.g. `{name?, width?, height?, frameRate?, duration? (s)}`) and whether it can run now (`why` if not). Every menu item, shortcut and panel gesture maps to one of these ids; run them with execute_command. Narrow with `filter` (e.g. `layer.new`, `keys`, `effect`).",
+        description: "List engine commands: id, label, menu path, shortcut, `params` doc (e.g. `{name?, width?, height?, frameRate?, duration? (s)}`) and whether it can run now (`why` if not). Every menu item, shortcut and panel gesture maps to one of these ids; run them with execute_command. Narrow with `filter` (e.g. `layer.new`, `keys`, `effect`); `compact: true` lists only ids and labels.",
        bridge_only: false,
        schema: || {
            schema(
                json!({
                    "filter": {"type": "string", "description": "Only commands whose id or label contains this text (case-insensitive)."},
                    "enabled_only": {"type": "boolean", "description": "Only commands that can run right now."},
-                    "schemas": {"type": "boolean", "description": "Also return each command's parameter JSON Schema (`schema`)."}
+                    "schemas": {"type": "boolean", "description": "Also return each command's parameter JSON Schema (`schema`)."},
+                    "compact": {"type": "boolean", "description": "Return only each command's `id` and `label` (overrides `schemas`)."}
                }),
                &[],
            )
@@ -615,7 +629,7 @@ static TOOLS: &[ToolDef] = &[
    },
    ToolDef {
        name: "get_layer",
-        description: "A layer's property tree (transform, masks, effects, text, shape contents, ...): leaf properties have a `path` usable with get_property/set_property/add_keyframe, plus uid, match id, name, type, value at `time`, keyframes and expression. Groups contain children; inspect them here, then select a leaf path. `flat: true` returns just a list of {path, type, value, keys, expression} (compact).",
+        description: "A layer's property tree (transform, masks, effects, text, shape contents, ...): leaf properties have a `path` usable with get_property/set_property/add_keyframe, plus uid, match id, name, type, value at `time`, keyframes and expression; popup (enum) properties add `options` ([{value, label}]). Groups contain children; inspect them here, then select a leaf path. `flat: true` returns just a list of {path, type, value, keys, expression, options} (compact).",
        bridge_only: false,
        schema: || {
            schema(
@@ -632,7 +646,7 @@ static TOOLS: &[ToolDef] = &[
    },
    ToolDef {
        name: "get_property",
-        description: "Read one property: type, value at `time` (comp seconds; default the current time), whether it is animated, its keyframes (time, value, in/out interpolation) and expression.",
+        description: "Read one property: type, value at `time` (comp seconds; default the current time), whether it is animated, its keyframes (time, value, in/out interpolation) and expression. Popup (enum) properties add `options`: [{value, label}], the values set_property takes.",
        bridge_only: false,
        schema: || {
            schema(
@@ -696,9 +710,17 @@ static TOOLS: &[ToolDef] = &[
    },
    ToolDef {
        name: "list_effects",
-        description: "The effect registry: id, After Effects name, category, GPU and 32-bpc support. Narrow with `filter` (id, name or category text). Apply with add_effect.",
+        description: "The effect registry: id, After Effects name, category, GPU and 32-bpc support. Narrow with `filter` (id, name or category text); `compact: true` lists only ids, names and categories. Apply with add_effect.",
        bridge_only: false,
-        schema: || schema(json!({"filter": {"type": "string", "description": "Only effects whose id, name or category contains this text."}}), &[]),
+        schema: || {
+            schema(
+                json!({
+                    "filter": {"type": "string", "description": "Only effects whose id, name or category contains this text."},
+                    "compact": {"type": "boolean", "description": "Return only each effect's `id`, `name` and `category`."}
+                }),
+                &[],
+            )
+        },
        run: list_effects,
    },
    ToolDef {
@@ -911,14 +933,15 @@ static TOOLS: &[ToolDef] = &[
    },
    ToolDef {
        name: "command_list",
-        description: "List engine commands: id, label, menu path, shortcut, `params` doc (e.g. `{name?, width?, height?, frameRate?, duration? (s)}`) and whether it can run now (`why` if not). Every menu item, shortcut and panel gesture maps to one of these ids; run them with execute_command. Narrow with `filter` (e.g. `layer.new`, `keys`, `effect`).",
+        description: "List engine commands: id, label, menu path, shortcut, `params` doc (e.g. `{name?, width?, height?, frameRate?, duration? (s)}`) and whether it can run now (`why` if not). Every menu item, shortcut and panel gesture maps to one of these ids; run them with execute_command. Narrow with `filter` (e.g. `layer.new`, `keys`, `effect`); `compact: true` lists only ids and labels.",
        bridge_only: false,
        schema: || {
            schema(
                json!({
                    "filter": {"type": "string", "description": "Only commands whose id or label contains this text (case-insensitive)."},
                    "enabled_only": {"type": "boolean", "description": "Only commands that can run right now."},
-                    "schemas": {"type": "boolean", "description": "Also return each command's parameter JSON Schema (`schema`)."}
+                    "schemas": {"type": "boolean", "description": "Also return each command's parameter JSON Schema (`schema`)."},
+                    "compact": {"type": "boolean", "description": "Return only each command's `id` and `label` (overrides `schemas`)."}
                }),
                &[],
            )
@@ -35,7 +35,7 @@ fn import_footage(qa: &mut Qa) -> (Value, Value) {
    // Footage: the sequence, and a layered PSD written by the app itself (Save Frame As ▸
    // Photoshop Layers) from a small comp.
    let seq = write_sequence(qa);
-    let imp = qa.exec("file.import", json!({"paths": [seq]}));
+    let imp = qa.exec("file.import", json!({"paths": [seq], "sequence": true}));
    let seq_item = imp["items"][0].clone();
    let project = qa.tool("get_project", json!({}));
    let it = project["items"].as_array().unwrap().iter().find(|i| i["id"] == seq_item).unwrap().clone();
@@ -52,7 +52,7 @@ fn shake_offset(f: u32) -> (i64, i64) {

 /// Import a sequence at 12 fps and make a comp of it; returns (comp, layer).
 fn plate_comp(qa: &mut Qa, first: &str, name: &str) -> (Value, Value) {
-    let item = qa.exec("file.import", json!({"paths": [first]}))["items"][0].clone();
+    let item = qa.exec("file.import", json!({"paths": [first], "sequence": true}))["items"][0].clone();
    qa.exec("file.interpretFootage", json!({"items": [item.clone()], "frameRate": 12}));
    let comp = qa.exec("comp.new", json!({"name": name, "width": 160, "height": 90, "frameRate": 12, "duration": 1}))["comp"].clone();
    let layer = qa.exec("layer.addItem", json!({"item": item}))["layer"].clone();
@@ -48,8 +48,10 @@ reconstruction, so prediction never drifts.
  reconstruction loop; full coefficient coding (all_zero, tx type, eob_pt, eob_extra,
  coeff_base_eob, coeff_base, coeff_br, dc_sign, Golomb) with the exact contexts.
 - **Rate control**: `ConstantQ(base_q_idx)`; `Bitrate { kbps }` adapts `base_q_idx` per frame
-  towards the average target (key frames get a lower quantizer and a larger share; the first
-  key frame is searched in a few passes).
+  towards the average target (key frames get a lower quantizer and a larger share of the budget of
+  their group of `keyint` frames, the inter frames the rest; the first key frame is searched in a
+  few passes, a later key frame that misses its budget by more than 19 % is coded again; the
+  deviation from the budget is paid back over 16 frames).

 ## Limits

@@ -3,7 +3,7 @@
 //! processes, so the reconstruction built here is exactly what a decoder produces; the syntax
 //! is written afterwards by `writer.rs`.

-use crate::pred::{INTRA_MODES_USED, InterBlock, IntraEdge, Plane, edges, predict_inter, predict_intra, subpel_plane};
+use crate::pred::{INTRA_MODES_USED, InterBlock, IntraEdge, Plane, edges, half_planes, predict_inter, predict_intra};
 use crate::tables::{
    AC_QLOOKUP, BLOCK_8X8, BLOCK_64X64, DC_PRED, DC_QLOOKUP, DCT_DCT, DEFAULT_SCAN_4X4, DEFAULT_SCAN_8X8, DEFAULT_SCAN_16X16, DEFAULT_SCAN_32X32, MODE_TO_TXFM,
    NEWMV, NUM_4X4_BLOCKS_WIDE, PARTITION_SPLIT, PARTITION_SUBSIZE, TX_4X4, TX_8X8, TX_16X16, TX_32X32, TX_64X64, TX_SET_DCTONLY, TX_SET_INTER_3,
@@ -174,6 +174,8 @@ pub(crate) struct Decider<'a> {
    ac_q: f32,
    dc_qi: i64,
    ac_qi: i64,
+    /// Smallest magnitude that quantises to a non-zero level, `[dc, ac][intra]`.
+    dead_zone: [[f32; 2]; 2],
    lambda: f64,
    lambda_sad: f64,
    /// Half-sample interpolations of the reference luma (visible area): (8, 0), (0, 8), (8, 8).
@@ -183,6 +185,9 @@ pub(crate) struct Decider<'a> {
 }

 const MODE_BITS_INTRA: f64 = 3.0;
+/// Dead-zone quantiser rounding offsets (below one half) for inter and intra blocks.
+const INTER_RND: f32 = 0.30;
+const INTRA_RND: f32 = 0.38;

 impl<'a> Decider<'a> {
    pub fn new(g: &'a FrameGeom, bd: u32, qidx: u8, intra_only: bool, src: &'a [Plane; 3], refr: Option<&'a RefFrame>) -> Self {
@@ -209,10 +214,11 @@ impl<'a> Decider<'a> {
            ac_q: ac_qi as f32,
            dc_qi,
            ac_qi,
+            dead_zone: [dc_qi, ac_qi].map(|q| [INTER_RND, INTRA_RND].map(|rnd| zero_threshold(q as f32, rnd))),
            lambda,
            lambda_sad: lambda.sqrt(),
            half: match refr {
-                Some(rf) => [(8, 0), (0, 8), (8, 8)].map(|(fx, fy)| subpel_plane(&rf.planes[0], g.width, g.height, fx, fy, bd)),
+                Some(rf) => half_planes(&rf.planes[0], g.width, g.height, bd),
                None => Default::default(),
            },
            scratch: None,
@@ -577,8 +583,9 @@ impl<'a> Decider<'a> {
            let (dy, dx) = (m[0] >> 3, m[1] >> 3);
            dx >= lim_x.0 && dx <= lim_x.1 && dy >= lim_y.0 && dy <= lim_y.1
        };
+        let lg = log2_table();
        let mv_bits = |m: [i32; 2]| -> f64 {
-            let comp = |d: i32| if d == 0 { 0.5 } else { 2.0 + 2.0 * ((d.abs() / 8) as f64 + 1.0).log2() };
+            let comp = |d: i32| if d == 0 { 0.5 } else { 2.0 + 2.0 * log2_of(lg, (d.abs() / 8) as usize + 1) };
            comp(m[0] - pred_mv[0]) + comp(m[1] - pred_mv[1])
        };
        let cost =
@@ -863,12 +870,18 @@ impl<'a> Decider<'a> {
        }
        forward_2d(res, coef, n, tx_type);
        // dead-zone quantiser: rounding offset below one half
-        let rnd = if intra { 0.38f32 } else { 0.30f32 };
+        let rnd = if intra { INTRA_RND } else { INTER_RND };
+        let [dc_thr, ac_thr] = [self.dead_zone[0][intra as usize], self.dead_zone[1][intra as usize]];
        levels.fill(0);
        let mut nonzero = false;
        for (k, (&cf, l)) in coef.iter().zip(levels.iter_mut()).enumerate() {
-            let q = if k == 0 { self.dc_q } else { self.ac_q };
-            let a = (cf.abs() / q + rnd).floor() as i32;
+            let (q, thr) = if k == 0 { (self.dc_q, dc_thr) } else { (self.ac_q, ac_thr) };
+            // dead zone: below the exact threshold the level is zero, no division needed
+            if cf.abs() < thr {
+                continue;
+            }
+            // the operand is >= 0, so truncation equals floor
+            let a = (cf.abs() / q + rnd) as i32;
            if a != 0 {
                *l = if cf < 0.0 { -a.min(1 << 16) } else { a.min(1 << 16) };
                nonzero = true;
@@ -913,6 +926,33 @@ impl<'a> Decider<'a> {
    }
 }

+/// Smallest `x >= 0` with `(x / q + rnd) as i32 >= 1` in f32 arithmetic. The expression is
+/// monotone in `x`, so a binary search over the bit patterns finds the exact boundary.
+fn zero_threshold(q: f32, rnd: f32) -> f32 {
+    let (mut lo, mut hi) = (0u32, f32::MAX.to_bits());
+    while lo < hi {
+        let mid = lo + (hi - lo) / 2;
+        if (f32::from_bits(mid) / q + rnd) as i32 >= 1 {
+            hi = mid;
+        } else {
+            lo = mid + 1;
+        }
+    }
+    f32::from_bits(lo)
+}
+
+const LOG2_TABLE_LEN: usize = 1025;
+
+/// `log2(i)` for `i < LOG2_TABLE_LEN`, computed with the same `f64::log2` call as the direct form.
+fn log2_table() -> &'static [f64; LOG2_TABLE_LEN] {
+    static TABLE: std::sync::OnceLock<[f64; LOG2_TABLE_LEN]> = std::sync::OnceLock::new();
+    TABLE.get_or_init(|| std::array::from_fn(|i| (i as f64).log2()))
+}
+
+fn log2_of(table: &[f64; LOG2_TABLE_LEN], v: usize) -> f64 {
+    if v < LOG2_TABLE_LEN { table[v] } else { (v as f64).log2() }
+}
+
 /// Unnormalised Walsh-Hadamard transform of 4 or 8 values, in place.
 fn hadamard(v: &mut [i32]) {
    let n = v.len();
@@ -941,13 +981,14 @@ fn estimate_bits(levels: &[i32], tx_sz: usize) -> f64 {
    if eob == 0 {
        return 1.0;
    }
-    let mut bits = 3.0 + (eob as f64).log2();
+    let lg = log2_table();
+    let mut bits = 3.0 + log2_of(lg, eob);
    for &pos in &scan[..eob] {
        let a = levels[pos as usize].unsigned_abs();
        bits += match a {
            0 => 0.7,
            1 => 2.5,
-            _ => 3.5 + 1.6 * (a as f64).log2(),
+            _ => 3.5 + 1.6 * log2_of(lg, a as usize),
        };
    }
    bits
@@ -961,3 +1002,64 @@ pub(crate) fn scan_for(tx_sz: usize) -> &'static [u16] {
        _ => &DEFAULT_SCAN_32X32,
    }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::tables::{AC_QLOOKUP, DC_QLOOKUP};
+
+    /// The quantiser as it was before the dead-zone threshold and the truncation.
+    fn quant_ref(cf: f32, q: f32, rnd: f32) -> i32 {
+        (cf.abs() / q + rnd).floor() as i32
+    }
+
+    fn quant_new(cf: f32, q: f32, rnd: f32, thr: f32) -> i32 {
+        if cf.abs() < thr {
+            return 0;
+        }
+        (cf.abs() / q + rnd) as i32
+    }
+
+    #[test]
+    fn dead_zone_threshold_is_exact() {
+        let mut state = 0x1234_5678_9abc_def0u64;
+        let mut next = move || {
+            state ^= state << 13;
+            state ^= state >> 7;
+            state ^= state << 17;
+            state
+        };
+        for table in AC_QLOOKUP.iter().chain(DC_QLOOKUP.iter()) {
+            for &qi in table.iter() {
+                let q = qi as f32;
+                for rnd in [INTER_RND, INTRA_RND] {
+                    let thr = zero_threshold(q, rnd);
+                    // the boundary itself and its neighbours
+                    let b = thr.to_bits();
+                    for bits in b.saturating_sub(3)..=b + 3 {
+                        let cf = f32::from_bits(bits);
+                        assert_eq!(quant_ref(cf, q, rnd), quant_new(cf, q, rnd, thr), "q {q} rnd {rnd} cf {cf}");
+                        assert_eq!(quant_ref(-cf, q, rnd), quant_new(-cf, q, rnd, thr));
+                    }
+                    for _ in 0..200 {
+                        let cf = f32::from_bits((next() >> 32) as u32 & 0x7fff_ffff);
+                        if cf.is_nan() {
+                            continue;
+                        }
+                        assert_eq!(quant_ref(cf, q, rnd), quant_new(cf, q, rnd, thr));
+                        let cf = (next() % 100_000) as f32 / 100.0;
+                        assert_eq!(quant_ref(cf, q, rnd), quant_new(cf, q, rnd, thr));
+                    }
+                }
+            }
+        }
+    }
+
+    #[test]
+    fn log2_table_matches_direct_log2() {
+        let t = log2_table();
+        for v in 1..3000usize {
+            assert_eq!(log2_of(t, v).to_bits(), (v as f64).log2().to_bits(), "{v}");
+        }
+    }
+}
@@ -24,6 +24,7 @@ use bitw::{BitWriter, obu};
 use decide::{Decider, FrameGeom, RefFrame};
 use loopfilter::{LfInfo, loop_filter};
 use pred::Plane;
+use tables::AC_QLOOKUP;
 use writer::TileWriter;

 /// Rate control.
@@ -136,10 +137,118 @@ struct RateState {
    frame_bits: f64,
    /// Quantizer index for inter frames (continuous).
    q: f64,
+    /// Key frame quantizer index minus the inter frame one.
+    key_off: f64,
+    /// Quantizer index steps per halving of the frame size, measured from consecutive inter
+    /// frames (the size/quantizer curve is much steeper than the default on noisy content).
+    slope: f64,
+    /// Quantizer index and size (in bits) of the previous inter frame.
+    prev_inter: Option<(f64, f64)>,
    /// Accumulated (spent - budget) bits.
    debt: f64,
 }

+/// Quantizer index steps per halving of the frame size before any measurement.
+const RC_SLOPE: f64 = 28.0;
+/// Fraction of the quantizer step the size error asks for that is applied per frame.
+const RC_GAIN: f64 = 0.8;
+/// Frames over which an accumulated deviation from the budget is paid back.
+const RC_PAYBACK: f64 = 16.0;
+
+impl RateState {
+    /// The nominal bit budget and the starting quantizer index of a key or inter frame. A key
+    /// frame gets a larger share, and the inter frames of the group get the rest, so that a whole
+    /// group of `keyint` frames adds up to `keyint * frame_bits`.
+    fn frame_budget(&self, keyint: u32, key: bool) -> (f64, f64) {
+        let keyint = keyint.max(1) as f64;
+        let boost = (1.0 + (keyint.clamp(1.0, 60.0) - 1.0).sqrt() * 0.75).min(0.5 * keyint + 0.5);
+        if key {
+            (self.frame_bits * boost, (self.q + self.key_off).clamp(1.0, 255.0))
+        } else if keyint > 1.0 {
+            (self.frame_bits * (keyint - boost) / (keyint - 1.0), self.q)
+        } else {
+            (self.frame_bits, self.q)
+        }
+    }
+
+    /// Adapts the quantizers to the size of the frame just coded at `q_used` against `target`.
+    fn update(&mut self, key: bool, first: bool, q_used: f64, bits: f64, target: f64) {
+        let err = (bits / target).log2().clamp(-1.5, 1.5);
+        if first && key {
+            // four passes ran: the key frame quantizer is known, the inter one follows from the offset
+            self.q = (q_used - self.key_off).clamp(1.0, 255.0);
+        } else if key {
+            self.key_off = q_used - self.q + RC_GAIN * self.slope * err;
+        } else {
+            if let Some((pq, pbits)) = self.prev_inter {
+                let (dq, dr) = (q_used - pq, (pbits / bits).log2());
+                if dq.abs() >= 3.0 && dr.abs() >= 0.15 && dq * dr > 0.0 {
+                    self.slope = (0.6 * self.slope + 0.4 * (dq / dr)).clamp(3.0, 45.0);
+                }
+            }
+            self.prev_inter = Some((q_used, bits));
+            self.q = (q_used + RC_GAIN * self.slope * err).clamp(1.0, 255.0);
+        }
+    }
+}
+
+/// Most passes on the first frame, and how far from the target (octaves, 3 %) its size may be
+/// before it is accepted.
+const RC_FIRST_PASSES: usize = 4;
+const RC_FIRST_TOLERANCE: f64 = 0.04;
+/// Quantizer index steps per halving of the size, for the first correction of the first frame
+/// (the starting quantizer comes from the bits per sample; the first pass shows how far off it
+/// is, and from there on the passes are placed by `next_probe_q`).
+const RC_FIRST_SLOPE: f64 = 30.0;
+/// The same for a key frame after the first: coded again when its size is more than 0.25 octaves
+/// (19 %) off the target.
+const RC_KEY_PASSES: usize = 3;
+const RC_KEY_TOLERANCE: f64 = 0.25;
+/// Octaves of frame size per octave of quantizer step assumed for the first correction of a frame.
+const RC_PROBE_SLOPE: f64 = 1.0;
+/// Largest change of the quantizer step (octaves) between two passes on one frame.
+const RC_PROBE_MAX_STEP: f64 = 2.0;
+
+/// The quantizer index whose step size is closest to `2^x`.
+fn q_for_step(bit_depth: u8, x: f64) -> u8 {
+    let table = &AC_QLOOKUP[((bit_depth - 8) / 2) as usize];
+    let mut best = 1;
+    for q in 1..=255usize {
+        if ((table[q] as f64).log2() - x).abs() < ((table[best] as f64).log2() - x).abs() {
+            best = q;
+        }
+    }
+    best as u8
+}
+
+/// The next quantizer to try for a frame, from the `(quantizer, log2(size / target))`
+/// pairs coded so far. The size follows the quantizer step (not the index, which is linear in the
+/// step only below about 60) in a near log-log line: false position between the closest pair of
+/// passes that enclose the target, otherwise a step from the latest one with the slope of the
+/// last two. `None` when no untried quantizer lies between the enclosing passes.
+fn next_probe_q(bit_depth: u8, tried: &[(u8, f64)]) -> Option<u8> {
+    let table = &AC_QLOOKUP[((bit_depth - 8) / 2) as usize];
+    let x = |q: u8| (table[q as usize] as f64).log2();
+    let over = tried.iter().filter(|t| t.1 > 0.0).max_by_key(|t| t.0);
+    let under = tried.iter().filter(|t| t.1 <= 0.0).min_by_key(|t| t.0);
+    if let (Some(&(q_lo, e_lo)), Some(&(q_hi, e_hi))) = (over, under) {
+        if q_hi - q_lo < 2 {
+            return None;
+        }
+        let next = x(q_lo) + (x(q_hi) - x(q_lo)) * e_lo / (e_lo - e_hi);
+        return Some(q_for_step(bit_depth, next).clamp(q_lo + 1, q_hi - 1));
+    }
+    let &(q, err) = tried.last()?;
+    let mut slope = RC_PROBE_SLOPE;
+    if let [.., (q0, e0), (q1, e1)] = tried
+        && (x(*q1) - x(*q0)).abs() > 0.05
+        && (e0 - e1) / (x(*q1) - x(*q0)) > 0.0
+    {
+        slope = ((e0 - e1) / (x(*q1) - x(*q0))).clamp(0.25, 3.0);
+    }
+    Some(q_for_step(bit_depth, x(q) + (err / slope).clamp(-RC_PROBE_MAX_STEP, RC_PROBE_MAX_STEP)))
+}
+
 /// AV1 encoder. Frames come out in input order (no hidden/reordered frames).
 pub struct Encoder {
    cfg: EncoderConfig,
@@ -185,7 +294,7 @@ impl Encoder {
                // initial guess from the bits per sample
                let bpp = frame_bits / (cfg.width as f64 * cfg.height as f64);
                let q = (110.0 - 40.0 * (bpp / 0.1).log2()).clamp(20.0, 230.0);
-                Some(RateState { frame_bits, q, debt: 0.0 })
+                Some(RateState { frame_bits, q, key_off: -24.0, slope: RC_SLOPE, prev_inter: None, debt: 0.0 })
            }
        };
        let mut enc = Encoder { cfg, geom, level, seq_obu: Vec::new(), frame_num: 0, refr: None, rc };
@@ -471,38 +580,52 @@ impl Encoder {

    fn encode_rate_controlled(&mut self, src: &[Plane; 3], key: bool, rc: &mut RateState) -> (Vec<u8>, RefFrame) {
        let first = self.frame_num == 0;
-        let (frame_bits, debt, q_inter) = (rc.frame_bits, rc.debt, rc.q);
-        // key frames get a lower quantizer and a larger share of the budget
-        let key_boost = 1.0 + (self.cfg.keyint.clamp(1, 60) as f64 - 1.0).sqrt() * 0.75;
-        let budget = if key { frame_bits * key_boost } else { frame_bits };
-        // pay back a fraction of the accumulated deviation
-        let target = (budget - debt * 0.25).max(budget * 0.25);
-        let mut q = if key { q_inter - 24.0 } else { q_inter };
-        let mut best: Option<(Vec<u8>, RefFrame, f64)> = None;
-        let passes = if first { 4 } else { 1 };
-        for pass in 0..passes {
+        let (budget, q_start) = rc.frame_budget(self.cfg.keyint, key);
+        // pay back the accumulated deviation over the next RC_PAYBACK frames
+        let target = (budget - rc.debt / RC_PAYBACK).clamp(budget * 0.35, budget * 2.0);
+        let mut q = q_start;
+        let mut best: Option<(Vec<u8>, RefFrame, f64, f64)> = None;
+        // The first frame is coded up to four times to find its quantizer (it fixes the
+        // quantizers of everything after it), a later key frame up to three times (it is a large
+        // part of the budget of its group). A frame is coded again only while its size is far from
+        // the target and an untried quantizer is left to try; other frames are coded once.
+        let (max_passes, tolerance) = if first {
+            (RC_FIRST_PASSES, RC_FIRST_TOLERANCE)
+        } else if key {
+            (RC_KEY_PASSES, RC_KEY_TOLERANCE)
+        } else {
+            (1, 0.0)
+        };
+        let mut tried: Vec<(u8, f64)> = Vec::new();
+        for _ in 0..max_passes {
            let qi = q.round().clamp(1.0, 255.0) as u8;
+            if tried.iter().any(|t| t.0 == qi) {
+                break;
+            }
            let (obu, rf) = self.encode_frame(src, key, qi);
            let bits = obu.len() as f64 * 8.0;
            let err = (bits / target).log2();
-            let better = best.as_ref().is_none_or(|b| err.abs() < (b.2 / target).log2().abs());
-            if better {
-                best = Some((obu, rf, bits));
+            tried.push((qi, err));
+            if best.as_ref().is_none_or(|b| err.abs() < (b.2 / target).log2().abs()) {
+                best = Some((obu, rf, bits, qi as f64));
            }
-            if pass + 1 < passes {
-                q = (q + 30.0 * err).clamp(1.0, 255.0);
+            if err.abs() <= tolerance {
+                break;
+            }
+            let next = if first && tried.len() == 1 {
+                Some((q + RC_FIRST_SLOPE * err).clamp(1.0, 255.0))
+            } else {
+                next_probe_q(self.cfg.bit_depth, &tried).map(f64::from)
+            };
+            match next {
+                Some(next) => q = next,
+                None => break,
            }
        }
        // At least one pass ran, so `best` is set.
-        let Some((obu, rf, bits)) = best else { return self.encode_frame(src, key, q.round().clamp(1.0, 255.0) as u8) };
+        let Some((obu, rf, bits, q_used)) = best else { return self.encode_frame(src, key, q.round().clamp(1.0, 255.0) as u8) };
        rc.debt += bits - budget;
-        // adapt the inter quantizer: about 30 index steps per doubling of the rate
-        let err = (bits / target).log2().clamp(-1.0, 1.0);
-        if first && key {
-            rc.q = (q + 24.0).clamp(1.0, 255.0);
-        } else {
-            rc.q = (rc.q + 12.0 * err).clamp(1.0, 255.0);
-        }
+        rc.update(key, first, q_used, bits, target);
        (obu, rf)
    }

@@ -297,7 +297,8 @@ pub(crate) fn predict_inter(refp: &Plane, block: &InterBlock, pred: &mut [u16])

 /// The visible `w x h` area of a reference plane interpolated at the sub-sample phase
 /// (`fx`, `fy`) (1/16 units) with the EIGHTTAP filter, as `predict_inter` computes it for
-/// blocks wider and taller than 4. Used for motion search.
+/// blocks wider and taller than 4. The reference for `half_planes`, which the encoder uses.
+#[cfg(test)]
 pub(crate) fn subpel_plane(refp: &Plane, w: usize, h: usize, fx: usize, fy: usize, bit_depth: u32) -> Vec<u16> {
    let kh = &SUBPEL_FILTERS[EIGHTTAP][fx];
    let kv = &SUBPEL_FILTERS[EIGHTTAP][fy];
@@ -327,6 +328,66 @@ pub(crate) fn subpel_plane(refp: &Plane, w: usize, h: usize, fx: usize, fy: usiz
    out
 }

+/// The three half-sample planes (8, 0), (0, 8), (8, 8) of `subpel_plane` in one pass: the
+/// horizontal half-sample pass is shared by (8, 0) and (8, 8), and the phase-0 kernels reduce to
+/// exact shifts (Round2( 128 * v, 11 ) = Round2( v, 4 ), Round2( 16 * s, 11 ) = Round2( s, 7 )),
+/// so the result equals three `subpel_plane` calls bit for bit.
+pub(crate) fn half_planes(refp: &Plane, w: usize, h: usize, bit_depth: u32) -> [Vec<u16>; 3] {
+    let k = &SUBPEL_FILTERS[EIGHTTAP][8];
+    let max = (1i32 << bit_depth) - 1;
+    let (lx, ly) = (w as i32 - 1, h as i32 - 1);
+    // horizontal pass at phase 8: Round2( sum, 3 )
+    let mut hp = vec![0i32; w * h];
+    for y in 0..h {
+        let row = &refp.row(y)[..w];
+        let out = &mut hp[y * w..y * w + w];
+        let tap = |x: i32| -> i32 {
+            let mut s = 0i32;
+            for t in 0..8 {
+                s += k[t] as i32 * row[(x + t as i32 - 3).clamp(0, lx) as usize] as i32;
+            }
+            round2(s, 3)
+        };
+        if w >= 8 {
+            for x in 0..3 {
+                out[x] = tap(x as i32);
+            }
+            for (x, o) in out.iter_mut().enumerate().take(w - 4).skip(3) {
+                let seg = &row[x - 3..x + 5];
+                let mut s = 0i32;
+                for t in 0..8 {
+                    s += k[t] as i32 * seg[t] as i32;
+                }
+                *o = round2(s, 3);
+            }
+            for x in w - 4..w {
+                out[x] = tap(x as i32);
+            }
+        } else {
+            for (x, o) in out.iter_mut().enumerate() {
+                *o = tap(x as i32);
+            }
+        }
+    }
+    let p80: Vec<u16> = hp.iter().map(|&v| round2(v, 4).clamp(0, max) as u16).collect();
+    let mut p08 = vec![0u16; w * h];
+    let mut p88 = vec![0u16; w * h];
+    for y in 0..h {
+        let rows: [usize; 8] = std::array::from_fn(|t| (y as i32 + t as i32 - 3).clamp(0, ly) as usize);
+        let (o08, o88) = (&mut p08[y * w..y * w + w], &mut p88[y * w..y * w + w]);
+        for x in 0..w {
+            let (mut a, mut b) = (0i32, 0i32);
+            for t in 0..8 {
+                a += k[t] as i32 * refp.data[rows[t] * refp.stride + x] as i32;
+                b += k[t] as i32 * hp[rows[t] * w + x];
+            }
+            o08[x] = round2(a, 7).clamp(0, max) as u16;
+            o88[x] = round2(b, 11).clamp(0, max) as u16;
+        }
+    }
+    [p80, p08, p88]
+}
+
 #[cfg(test)]
 mod tests {
    use super::*;
@@ -361,6 +422,20 @@ mod tests {
        }
    }

+    #[test]
+    fn half_planes_match_subpel_plane() {
+        for (w, h) in [(37usize, 29usize), (5, 3), (1, 1), (64, 64)] {
+            let mut p = Plane::new(64, 64);
+            for (i, v) in p.data.iter_mut().enumerate() {
+                *v = ((i * 7919) % 1024) as u16;
+            }
+            let hp = half_planes(&p, w, h, 10);
+            for (i, (fx, fy)) in [(8, 0), (0, 8), (8, 8)].into_iter().enumerate() {
+                assert_eq!(hp[i], subpel_plane(&p, w, h, fx, fy, 10), "{w}x{h} phase ({fx}, {fy})");
+            }
+        }
+    }
+
    #[test]
    fn phase_zero_filters_are_impulses() {
        for f in SUBPEL_FILTERS.iter() {
@@ -32,6 +32,7 @@ fn sin128(angle: i32) -> i64 {
    cos128(angle - 64)
 }

+#[inline(always)]
 fn brev(num_bits: u32, x: usize) -> usize {
    let mut t = 0;
    for i in 0..num_bits {
@@ -63,8 +64,11 @@ fn hd(t: &mut [i32], a: usize, b: usize, flip: bool, r: u32) {
    t[b] = (x - y).clamp(lo, hi);
 }

-/// Inverse DCT of length 2^n, n = 2..=5 (7.13.2.3), in place.
-fn inverse_dct(t: &mut [i32], n: u32, r: u32) {
+/// Inverse DCT of length 2^N, N = 2..=5 (7.13.2.3), in place. `N` is a const generic so that the
+/// bit-reversal permutations and loop bounds fold at compile time.
+#[inline(always)]
+fn inverse_dct_n<const N: u32>(t: &mut [i32], r: u32) {
+    let n = N;
    let len = 1usize << n;
    let mut copy = [0i32; 32];
    copy[..len].copy_from_slice(&t[..len]);
@@ -76,6 +80,7 @@ fn inverse_dct(t: &mut [i32], n: u32, r: u32) {
 }

 /// Rotate the high-frequency branches before the four-point core.
+#[inline(always)]
 fn inverse_dct_initial_stages(t: &mut [i32], n: u32, r: u32) {
    if n >= 5 {
        for i in 0..8 {
@@ -112,6 +117,7 @@ fn inverse_dct_initial_stages(t: &mut [i32], n: u32, r: u32) {
 }

 /// Evaluate the four-point core and merge progressively larger branches.
+#[inline(always)]
 fn inverse_dct_final_stages(t: &mut [i32], n: u32, r: u32) {
    for i in 0..2 {
        bf(t, 2 * i, 2 * i + 1, 32 + 16 * i as i32, i == 0);
@@ -190,6 +196,7 @@ const SINPI_2_9: i64 = 2482;
 const SINPI_3_9: i64 = 3344;
 const SINPI_4_9: i64 = 3803;

+#[inline(always)]
 fn inverse_adst4(t: &mut [i32]) {
    let (t0, t1, t2, t3) = (t[0] as i64, t[1] as i64, t[2] as i64, t[3] as i64);
    let mut s = [SINPI_1_9 * t0, SINPI_2_9 * t0, SINPI_3_9 * t1, SINPI_4_9 * t2, SINPI_1_9 * t2, SINPI_2_9 * t3, SINPI_4_9 * t3];
@@ -207,7 +214,9 @@ fn inverse_adst4(t: &mut [i32]) {
    }
 }

-fn adst_in_permute(t: &mut [i32], n: u32) {
+#[inline(always)]
+fn adst_in_permute<const N: u32>(t: &mut [i32]) {
+    let n = N;
    let n0 = 1usize << n;
    let mut copy = [0i32; 16];
    copy[..n0].copy_from_slice(&t[..n0]);
@@ -217,7 +226,9 @@ fn adst_in_permute(t: &mut [i32], n: u32) {
    }
 }

-fn adst_out_permute(t: &mut [i32], n: u32) {
+#[inline(always)]
+fn adst_out_permute<const N: u32>(t: &mut [i32]) {
+    let n = N;
    let n0 = 1usize << n;
    let mut copy = [0i32; 16];
    copy[..n0].copy_from_slice(&t[..n0]);
@@ -231,8 +242,9 @@ fn adst_out_permute(t: &mut [i32], n: u32) {
    }
 }

+#[inline(always)]
 fn inverse_adst8(t: &mut [i32], r: u32) {
-    adst_in_permute(t, 3);
+    adst_in_permute::<3>(t);
    for i in 0..4 {
        bf(t, 2 * i, 2 * i + 1, 60 - 16 * i as i32, true);
    }
@@ -250,11 +262,12 @@ fn inverse_adst8(t: &mut [i32], r: u32) {
    for i in 0..2 {
        bf(t, 2 + 4 * i, 3 + 4 * i, 32, true);
    }
-    adst_out_permute(t, 3);
+    adst_out_permute::<3>(t);
 }

+#[inline(always)]
 fn inverse_adst16(t: &mut [i32], r: u32) {
-    adst_in_permute(t, 4);
+    adst_in_permute::<4>(t);
    for i in 0..8 {
        bf(t, 2 * i, 2 * i + 1, 62 - 8 * i as i32, true);
    }
@@ -283,7 +296,7 @@ fn inverse_adst16(t: &mut [i32], r: u32) {
    for i in 0..4 {
        bf(t, 2 + 4 * i, 3 + 4 * i, 32, true);
    }
-    adst_out_permute(t, 4);
+    adst_out_permute::<4>(t);
 }

 /// 1-D transform kind.
@@ -308,6 +321,17 @@ pub(crate) fn kinds(tx_type: usize) -> (Kind, Kind) {
    }
 }

+#[inline(always)]
+fn inverse_dct(t: &mut [i32], n: u32, r: u32) {
+    match n {
+        2 => inverse_dct_n::<2>(t, r),
+        3 => inverse_dct_n::<3>(t, r),
+        4 => inverse_dct_n::<4>(t, r),
+        _ => inverse_dct_n::<5>(t, r),
+    }
+}
+
+#[inline(always)]
 fn inverse_1d(t: &mut [i32], kind: Kind, n: u32, r: u32) {
    match kind {
        Kind::Dct => inverse_dct(t, n, r),
@@ -322,7 +346,17 @@ fn inverse_1d(t: &mut [i32], kind: Kind, n: u32, r: u32) {
 /// 2-D inverse transform (7.13.3) of a square `n x n` block (n = 4..=32) of dequantised
 /// coefficients (row stride `n`) into `residual` (row stride `n`).
 pub(crate) fn inverse_2d(dequant: &[i32], residual: &mut [i32], tx_sz: usize, tx_type: usize, bit_depth: u32) {
-    let log2 = TX_WIDTH_LOG2[tx_sz] as u32;
+    match TX_WIDTH_LOG2[tx_sz] {
+        2 => inverse_2d_n::<2>(dequant, residual, tx_sz, tx_type, bit_depth),
+        3 => inverse_2d_n::<3>(dequant, residual, tx_sz, tx_type, bit_depth),
+        4 => inverse_2d_n::<4>(dequant, residual, tx_sz, tx_type, bit_depth),
+        _ => inverse_2d_n::<5>(dequant, residual, tx_sz, tx_type, bit_depth),
+    }
+}
+
+/// `inverse_2d` for a block of width `1 << LOG2`.
+fn inverse_2d_n<const LOG2: u32>(dequant: &[i32], residual: &mut [i32], tx_sz: usize, tx_type: usize, bit_depth: u32) {
+    let log2 = LOG2;
    let n = 1usize << log2;
    let row_shift = TRANSFORM_ROW_SHIFT[tx_sz] as u32;
    let row_clamp = bit_depth + 8;
@@ -429,6 +463,51 @@ fn basis(kind: Kind, n: usize) -> &'static [f32] {
 /// Forward 2-D transform of the `n x n` residual (row stride `n`) into orthonormal-domain
 /// coefficients scaled by 8 (so that `level = out / q` with the spec's dequantiser).
 pub(crate) fn forward_2d(residual: &[i32], out: &mut [f32], n: usize, tx_type: usize) {
+    match n {
+        4 => forward_2d_n::<4, 16>(residual, out, tx_type),
+        8 => forward_2d_n::<8, 64>(residual, out, tx_type),
+        16 => forward_2d_n::<16, 256>(residual, out, tx_type),
+        _ => forward_2d_dyn(residual, out, n, tx_type),
+    }
+}
+
+/// `forward_2d` for a fixed size, so `tmp` is exactly `NN = N * N` floats (no 4 KiB zeroing).
+#[inline(always)]
+fn forward_2d_n<const N: usize, const NN: usize>(residual: &[i32], out: &mut [f32], tx_type: usize) {
+    let n = N;
+    let (ck, rk) = kinds(tx_type);
+    let bc = &basis(ck, n)[..NN];
+    let brt = &basis_t(rk, n)[..NN];
+    let residual = &residual[..NN];
+    let out = &mut out[..NN];
+    let mut tmp = [0f32; NN];
+    for i in 0..n {
+        let t = &mut tmp[i * n..i * n + n];
+        for j in 0..n {
+            let r = residual[i * n + j];
+            if r == 0 {
+                continue;
+            }
+            let r = r as f32;
+            for (o, &b) in t.iter_mut().zip(&brt[j * n..j * n + n]) {
+                *o += r * b;
+            }
+        }
+    }
+    out.iter_mut().for_each(|v| *v = 0.0);
+    for k in 0..n {
+        let o = &mut out[k * n..k * n + n];
+        for i in 0..n {
+            let b = 8.0 * bc[k * n + i];
+            for (v, &t) in o.iter_mut().zip(&tmp[i * n..i * n + n]) {
+                *v += b * t;
+            }
+        }
+    }
+}
+
+/// 32x32 (and any other size): a const-generic 32 version measured slower.
+fn forward_2d_dyn(residual: &[i32], out: &mut [f32], n: usize, tx_type: usize) {
    let (ck, rk) = kinds(tx_type);
    let bc = basis(ck, n);
    let brt = basis_t(rk, n);
@@ -80,6 +80,23 @@ fn bitrate_mode_tracks_target() {
    assert!(kbps > 400.0 / 2.0 && kbps < 400.0 * 2.0, "{kbps} kbit/s");
 }

+/// Over several key frame intervals the average rate stays within 5 % of the target, for a
+/// range of targets (the key frame budget is taken out of the inter frames of its group).
+#[test]
+fn bitrate_mode_is_accurate_over_many_groups() {
+    let n = 180;
+    for (kbps, keyint, bd) in [(40, 30, 8), (100, 30, 8), (200, 60, 8), (150, 20, 10)] {
+        let pics: Vec<Pic> = (0..n).map(|t| synth(192, 128, bd, t)).collect();
+        let mut c = cfg(192, 128, bd as u8, 0, keyint);
+        c.rate = RateControl::Bitrate { kbps };
+        let mut enc = effectcraft_av1enc::Encoder::new(c).unwrap();
+        let bits: usize = pics.iter().map(|p| enc.encode(&p.frame()).data.len() * 8).sum();
+        let got = bits as f64 / (n as f64 / 30.0) / 1000.0;
+        eprintln!("{bd} bit, keyint {keyint}: {got:.1} kbit/s for {kbps}");
+        assert!((got / kbps as f64 - 1.0).abs() < 0.05, "{got:.1} kbit/s for a {kbps} kbit/s target ({bd} bit, keyint {keyint})");
+    }
+}
+
 #[test]
 fn headers() {
    let enc = effectcraft_av1enc::Encoder::new(cfg(1920, 1080, 10, 100, 60)).unwrap();
@@ -97,7 +97,9 @@ pub fn rgb_to_hsl(r: f32, g: f32, b: f32) -> (f32, f32, f32) {
        return (0.0, 0.0, l);
    }
    let d = max - min;
-    let s = if l > 0.5 { d / (2.0 - max - min) } else { d / (max + min) };
+    let denom = if l > 0.5 { 2.0 - max - min } else { max + min };
+    // Over-range (HDR) or negative inputs can make the denominator zero or negative.
+    let s = if denom > 0.0 { d / denom } else { 1.0 };
    let h = if max == r {
        (((g - b) / d + if g < b { 6.0 } else { 0.0 }) / 6.0).rem_euclid(1.0)
    } else if max == g {
@@ -262,6 +264,20 @@ impl Label {
 mod tests {
    use super::*;

+    #[test]
+    fn hsl_round_trip_is_finite_for_out_of_range_colours() {
+        for (r, g, b) in [(1.5, 0.5, 0.5), (2.0, 0.1, 0.3), (-0.5, 0.2, 0.9)] {
+            let (h, s, l) = rgb_to_hsl(r, g, b);
+            assert!(h.is_finite() && s.is_finite() && l.is_finite(), "{h} {s} {l}");
+            let (r2, g2, b2) = hsl_to_rgb(h, s, l);
+            assert!(r2.is_finite() && g2.is_finite() && b2.is_finite(), "{r2} {g2} {b2}");
+        }
+        // A 32 bpc colour whose denominator stays positive still round-trips exactly.
+        let (h, s, l) = rgb_to_hsl(1.2, 0.5, 0.5);
+        let (r, g, b) = hsl_to_rgb(h, s, l);
+        assert!((r - 1.2).abs() < 1e-5 && (g - 0.5).abs() < 1e-5 && (b - 0.5).abs() < 1e-5, "{r} {g} {b}");
+    }
+
    #[test]
    fn hsv_to_rgb_tiny_negative_hue_is_red() {
        let (r, g, b) = hsv_to_rgb(-1e-9, 1.0, 1.0);
@@ -0,0 +1,97 @@
+//! Bounded parsed-JSON caches. Keep the content key with the owned source text so repeated
+//! renders do not rehash long analyses. Compare contents on lookup: evaluated parameter
+//! strings can be cloned, edited in place, or allocated again at an old address.
+
+use std::sync::{Arc, Mutex, OnceLock};
+
+struct Entry<T> {
+    json: Box<str>,
+    key: u64,
+    value: Arc<T>,
+}
+
+pub(crate) struct AnalysisCache<T> {
+    entries: OnceLock<Mutex<Vec<Entry<T>>>>,
+}
+
+pub(crate) fn fnv(bytes: &[u8]) -> u64 {
+    let mut h: u64 = 0xcbf2_9ce4_8422_2325;
+    for b in bytes {
+        h ^= *b as u64;
+        h = h.wrapping_mul(0x0100_0000_01b3);
+    }
+    h
+}
+
+impl<T> AnalysisCache<T> {
+    pub(crate) const fn new() -> Self {
+        Self { entries: OnceLock::new() }
+    }
+
+    pub(crate) fn get(&self, json: &str, parse: impl FnOnce(&str) -> Option<T>) -> Option<(u64, Arc<T>)> {
+        let entries = self.entries.get_or_init(Default::default);
+        {
+            let m = entries.lock().unwrap_or_else(|e| e.into_inner());
+            if let Some(e) = m.iter().rev().find(|e| e.json.as_ref() == json) {
+                return Some((e.key, e.value.clone()));
+            }
+        }
+        let value = Arc::new(parse(json)?);
+        let key = fnv(json.as_bytes());
+        let mut m = entries.lock().unwrap_or_else(|e| e.into_inner());
+        // Another render may have filled the entry while this one parsed it.
+        if let Some(e) = m.iter().rev().find(|e| e.json.as_ref() == json) {
+            return Some((e.key, e.value.clone()));
+        }
+        // Preserve the existing nine-entry bound and clear-on-overflow policy.
+        if m.len() > 8 {
+            m.clear();
+        }
+        m.push(Entry { json: json.into(), key, value: value.clone() });
+        Some((key, value))
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use std::cell::Cell;
+
+    #[test]
+    fn reuses_content_and_invalidates_same_allocation_edits() {
+        let cache = AnalysisCache::new();
+        let calls = Cell::new(0);
+        let parse = |s: &str| {
+            calls.set(calls.get() + 1);
+            Some(s.to_owned())
+        };
+        let mut json = String::from("analysis-1");
+        let (key, a) = cache.get(&json, parse).unwrap();
+        let copy = json.clone();
+        assert_ne!(json.as_ptr(), copy.as_ptr());
+        let (same_key, same) = cache.get(&copy, parse).unwrap();
+        assert_eq!(key, fnv(json.as_bytes()));
+        assert_eq!(key, same_key);
+        assert!(Arc::ptr_eq(&a, &same));
+        assert_eq!(calls.get(), 1);
+        let ptr = json.as_ptr();
+        json.replace_range(9..10, "2");
+        assert_eq!(ptr, json.as_ptr());
+        let (changed_key, changed) = cache.get(&json, parse).unwrap();
+        assert_ne!(key, changed_key);
+        assert_eq!(&*changed, "analysis-2");
+        assert_eq!(&*a, "analysis-1");
+        assert_eq!(calls.get(), 2);
+        assert!(cache.get("invalid", |_| None).is_none());
+        assert!(Arc::ptr_eq(&cache.get(&json, parse).unwrap().1, &changed));
+    }
+
+    #[test]
+    fn source_text_retention_is_bounded() {
+        let cache = AnalysisCache::new();
+        for i in 0..30 {
+            cache.get(&i.to_string(), |s| Some(s.to_owned())).unwrap();
+            assert!(cache.entries.get().unwrap().lock().unwrap().len() <= 9);
+        }
+    }
+}
@@ -206,6 +206,12 @@ pub fn reverses(id: &str) -> bool {
    id == "ec.audio.backwards"
 }

+/// Does each output sample depend only on the input sample at the same time (no state), so the
+/// mixer may run the effect in short pieces with parameters animated between them?
+pub fn per_sample(id: &str) -> bool {
+    matches!(id, "ec.audio.stereomixer" | "ec.audio.backwards")
+}
+
 /// Seconds of input history the effect needs before a block to reach the state it would have
 /// had when processing continuously.
 pub fn preroll(id: &str, params: &Params) -> f64 {
@@ -16,8 +16,9 @@
 //! on it draws the solved points (as the viewer shows them) into the frame. The viewer overlay, target and the Create
 //! commands live in the engine and the UI.

-use std::collections::HashMap;
-use std::sync::{Arc, Mutex, OnceLock};
+use std::sync::Arc;
+
+use crate::analysis_cache::AnalysisCache;

 use effectcraft_keyframe::Value;
 use effectcraft_project::ParamUi;
@@ -122,50 +123,24 @@ pub fn solve_key(st: &SolveSettings) -> String {
    format!("{:?}|{hfov}|{:?}|{:?}{lens}", st.shot, st.method, st.deleted)
 }

-fn fnv(bytes: &[u8]) -> u64 {
-    let mut h: u64 = 0xcbf2_9ce4_8422_2325;
-    for b in bytes {
-        h ^= *b as u64;
-        h = h.wrapping_mul(0x0100_0000_01b3);
-    }
-    h
-}
-
-type Cache<T> = Mutex<HashMap<u64, Arc<T>>>;
-
-fn cached<T>(c: &'static OnceLock<Cache<T>>, json: &str, parse: impl Fn(&str) -> Option<T>) -> Option<Arc<T>> {
-    let key = fnv(json.as_bytes());
-    let c = c.get_or_init(Default::default);
-    if let Some(a) = c.lock().unwrap_or_else(std::sync::PoisonError::into_inner).get(&key) {
-        return Some(a.clone());
-    }
-    let a = Arc::new(parse(json)?);
-    let mut m = c.lock().unwrap_or_else(std::sync::PoisonError::into_inner);
-    if m.len() > 8 {
-        m.clear();
-    }
-    m.insert(key, a.clone());
-    Some(a)
-}
-
 /// The stored feature tracks of an instance (`None` when not analysed).
 pub fn tracks(params: &Params) -> Option<Arc<CameraTracks>> {
-    static C: OnceLock<Cache<CameraTracks>> = OnceLock::new();
+    static C: AnalysisCache<CameraTracks> = AnalysisCache::new();
    let j = s(params, TRACKS);
    if j.is_empty() {
        return None;
    }
-    cached(&C, j, CameraTracks::from_json).filter(|t| !t.is_empty())
+    C.get(j, CameraTracks::from_json).map(|(_, a)| a).filter(|t| !t.is_empty())
 }

 /// The stored camera solve of an instance (`None` when not solved).
 pub fn solve(params: &Params) -> Option<Arc<CameraSolve>> {
-    static C: OnceLock<Cache<CameraSolve>> = OnceLock::new();
+    static C: AnalysisCache<CameraSolve> = AnalysisCache::new();
    let j = s(params, SOLVE);
    if j.is_empty() {
        return None;
    }
-    cached(&C, j, CameraSolve::from_json).filter(|t| !t.is_empty())
+    C.get(j, CameraSolve::from_json).map(|(_, a)| a).filter(|t| !t.is_empty())
 }

 /// Screen size (layer pixels) of a target drawn for a point at depth `z`, relative to the
@@ -338,6 +313,27 @@ mod tests {
        assert!(!st.lens_distortion && !solve_key(&st).contains("lens"));
    }

+    #[test]
+    fn tracks_and_solve_follow_analysis_replacements() {
+        let mut t = CameraTracks { frames: 3, start: 1.0, ..Default::default() };
+        let mut sol = CameraSolve { frames: vec![SolvedFrame::default()], start: 1.0, ..Default::default() };
+        let mut ps = params_with(&sol, false);
+        ps.values.insert(TRACKS.into(), Value::Str(t.to_json()));
+        assert_eq!(*tracks(&ps).unwrap(), t);
+        assert_eq!(*solve(&ps).unwrap(), sol);
+        t.start = 2.0;
+        sol.start = 2.0;
+        ps.values.insert(TRACKS.into(), Value::Str(t.to_json()));
+        ps.values.insert(SOLVE.into(), Value::Str(sol.to_json()));
+        assert_eq!(*tracks(&ps).unwrap(), t);
+        assert_eq!(*solve(&ps).unwrap(), sol);
+        assert_eq!(*tracks(&ps.clone()).unwrap(), t);
+        ps.values.insert(TRACKS.into(), Value::Str("invalid".into()));
+        ps.values.insert(SOLVE.into(), Value::Str(String::new()));
+        assert!(tracks(&ps).is_none());
+        assert!(solve(&ps).is_none());
+    }
+
    #[test]
    fn undistort_footage_remaps_through_the_solved_lens() {
        use effectcraft_track::camtrack::Distortion;
@@ -92,8 +92,8 @@ const CPU_ONLY_CONTROLS: &[(&str, &[&str])] = &[
 ];

 /// Whether the GPU kernel of effect `id` covers the instance's current settings (see
-/// `CPU_ONLY_CONTROLS`; plus Cell Pattern's HQ variants and Turbulent Displace's locked
-/// pinning).
+/// `CPU_ONLY_CONTROLS`; plus Cell Pattern's HQ variants, Turbulent Displace's locked
+/// pinning and CC Particle World's motion trails and textured squares).
 pub fn gpu_supported(id: &str, ctx: &crate::EffectCtx) -> bool {
    match id {
        "ec.generate.cellpattern" if (6..=10).contains(&ctx.params.e("cellPattern")) => return false,
@@ -101,6 +101,8 @@ pub fn gpu_supported(id: &str, ctx: &crate::EffectCtx) -> bool {
        // #1195: CC Particle World's motion trails (the averaged shutter samples) render on the
        // CPU kernel until the GPU particle pass supports them.
        "ec.sim.ccparticleworld" if ctx.env.shutter.filter(|(a, _, _)| *a > 0.0).is_some() => return false,
+        // #1465: Textured Square's Texture Layer is drawn on the CPU only.
+        "ec.sim.ccparticleworld" if crate::sim::particle_world_textured(ctx) => return false,
        _ => {}
    }
    let Some((_, controls)) = CPU_ONLY_CONTROLS.iter().find(|(e, _)| *e == id) else { return true };
@@ -182,6 +184,20 @@ mod tests {
        assert!(have == want, "docs/effects.md is stale: UPDATE_DOCS=1 cargo test -p effectcraft-effects --lib effects_doc_is_current");
    }

+    /// The README quotes the number of effects (#2565): every count it gives is the registry's.
+    #[test]
+    fn readme_effect_counts_are_current() {
+        let readme = std::fs::read_to_string(concat!(env!("CARGO_MANIFEST_DIR"), "/../../README.md")).unwrap_or_default();
+        let words: Vec<&str> = readme.split_whitespace().collect();
+        let counts: Vec<&str> = words
+            .windows(3)
+            .filter(|w| w[0].parse::<u32>().is_ok() && (w[1].starts_with("effects") || (w[1] == "built-in" && w[2].starts_with("effects"))))
+            .map(|w| w[0])
+            .collect();
+        let n = super::registry().len().to_string();
+        assert!(!counts.is_empty() && counts.iter().all(|c| *c == n), "README.md says {counts:?} effects; the registry has {n}");
+    }
+
    #[test]
    fn cpu_only_controls_keep_effects_off_the_gpu() {
        use effectcraft_keyframe::Value;
@@ -210,6 +226,10 @@ mod tests {
            assert!(!super::gpu_supported("ec.sim.ccparticleworld", &ctx));
        }
        assert!(ok("ec.sim.ccparticleworld", &[]));
+        // #1465: the Texture Layer keeps CC Particle World on the CPU only when Textured Square draws it.
+        let tex = ("particle/texture/textureLayer", Value::Layer(Some(1)));
+        assert!(ok("ec.sim.ccparticleworld", &[tex.clone(), ("particle/particleType", Value::Enum(2))]));
+        assert!(!ok("ec.sim.ccparticleworld", &[tex, ("particle/particleType", Value::Enum(8))]));
        assert!(ok("ec.generate.cellpattern", &[("cellPattern", Value::Enum(3))]));
        assert!(!ok("ec.generate.cellpattern", &[("cellPattern", Value::Enum(9))]));
        assert!(!ok("ec.distort.turbulentdisplace", &[("pinning", Value::Enum(9))]));
@@ -7,6 +7,11 @@
 //! pass for a precomp of a 3D comp. Without auxiliary channels they pass the layer through
 //! (EXtractoR still maps the layer's own R, G, B and A).
 //!
+//! 3D Layer Instance (Create 3D Layer Instance's own effect, Layer ▸ Create) is not an aux
+//! reader: it replaces the layer's pixels with a referenced layer's render — for a 3D model
+//! layer, its render on its own through the comp's camera — so 2D effects can be applied to a
+//! 3D layer's render.
+//!
 //! Aux pixels are looked up nearest-neighbour (IDs must not be interpolated) at each buffer
 //! pixel's layer position, so render scale and layer padding are respected.

@@ -582,6 +587,19 @@ fn extractor(ctx: &EffectCtx, mut b: Buf) -> Buf {
    b
 }

+/// A 2D copy of a referenced layer (Create 3D Layer Instance's solid): the layer's pixels
+/// replaced with the referenced layer's render, alpha included — the copy is transparent
+/// where the referenced layer isn't. A 3D model or primitive layer is rendered on its own
+/// through the comp's camera, as After Effects renders 3D layers; another layer is read with
+/// its masks and effects. With no layer chosen the effect passes the layer through, as a layer
+/// parameter with nothing chosen does.
+fn instance_3d(ctx: &EffectCtx, mut b: Buf) -> Buf {
+    if let Some(o) = ctx.layer_param("layer", true) {
+        b.img = crate::util::fit_layer(ctx, &b, &o, false);
+    }
+    b
+}
+
 pub fn specs() -> Vec<EffectSpec> {
    let text = |id: &'static str, name: &'static str, d: &str| p(id, name, Value::Str(d.into()), ParamUi::Text);
    vec![
@@ -682,6 +700,7 @@ pub fn specs() -> Vec<EffectSpec> {
            ],
            identifier,
        ),
+        spec("ec.3d.instance3d", "3D Layer Instance", vec![p("layer", "Layer", Value::Layer(None), ParamUi::Layer)], instance_3d),
    ]
 }

@@ -373,3 +373,29 @@ fn channel_extract_antialias_averages_sub_pixels() {
    let soft = run("ec.3d.channelextract", &[vals.as_slice(), &[("antialias", Value::Bool(true))]].concat(), &host);
    assert!((soft.get(5, 5)[0] - 0.5).abs() < 1e-5, "{:?}", soft.get(5, 5));
 }
+
+#[test]
+fn instance3d_replaces_the_pixels_with_the_referenced_layer() {
+    // Create 3D Layer Instance's copy: the chosen layer's render takes the place of the layer's
+    // own pixels, alpha included — the copy is transparent where the referenced layer isn't —
+    // and with no layer chosen the layer passes through.
+    struct Host(Image);
+    impl EffectHost for Host {
+        fn layer(&self, id: u64, _: bool) -> Option<LayerPixels> {
+            (id == 7).then(|| LayerPixels { buf: Buf { img: self.0.clone(), offset: [0.0; 2], scale: 1.0 }, size: [self.0.width as f64, self.0.height as f64] })
+        }
+        fn audio(&self, _: u64, _: f64, _: usize, _: u32) -> Option<Vec<f32>> {
+            None
+        }
+    }
+    let solid = || Image::filled(4, 4, [1.0, 1.0, 1.0, 1.0]);
+    let mut render = Image::new(4, 4);
+    render.set(1, 1, [1.0, 0.0, 0.0, 1.0]);
+    let env = EffectEnv { host: Some(&Host(render)), ..Default::default() };
+    let out = run_fx("ec.3d.instance3d", &[("layer", Value::Layer(Some(7)))], solid(), 0.0, env);
+    assert_eq!(out.img.get(1, 1), [1.0, 0.0, 0.0, 1.0], "the referenced layer's pixel");
+    assert_eq!(out.img.get(3, 3), [0.0; 4], "transparent where the referenced layer isn't");
+    // No layer chosen: the layer's own pixels.
+    let out = run_fx("ec.3d.instance3d", &[], solid(), 0.0, EffectEnv::default());
+    assert_eq!(out.img.data, solid().data);
+}
@@ -19,7 +19,7 @@ use effectcraft_project::ParamUi;
 use effectcraft_raster::{Image, Px};
 use rayon::prelude::*;

-use crate::generate::value_noise;
+use crate::generate::value_noise_linear_z;
 use crate::util::{SRC_NAMES, Src, fit_layer, layer_cover_pad, layer_rect, lerp4, map_xy, pick, premul, remap, smoothstep, src_at, unpremul};
 use crate::{Buf, EffectCtx, EffectSpec, col, num, p, popup, slider};

@@ -37,13 +37,15 @@ fn pct(max: f64) -> ParamUi {

 // ---------------------------------------------------------------- Turbulent Displace

+/// Fractional-octave fBm of value noise in 0..1. Evolution (`z`) is linear: with the eased z of
+/// plain value noise a few degrees of Evolution barely moved the pattern (#943).
 fn fbm(u: f64, v: f64, z: f64, seed: u32, octaves: f64, falloff: f32) -> f32 {
    let n = octaves.ceil().max(1.0) as usize;
    let frac = (octaves - octaves.floor()) as f32;
    let (mut sum, mut norm, mut amp, mut f) = (0.0f32, 0.0f32, 1.0f32, 1.0f32);
    for o in 0..n {
        let w = if o + 1 == n && frac > 0.0 { frac } else { 1.0 };
-        sum += value_noise(u as f32 * f, v as f32 * f, z as f32 + o as f32 * 5.17, seed.wrapping_add(o as u32 * 101)) * amp * w;
+        sum += value_noise_linear_z(u as f32 * f, v as f32 * f, z as f32 + o as f32 * 5.17, seed.wrapping_add(o as u32 * 101)) * amp * w;
        norm += amp * w;
        amp *= falloff;
        f *= 2.0;
@@ -93,6 +95,9 @@ fn turbulent_displace(ctx: &EffectCtx, mut b: Buf) -> Buf {
    let size = (ctx.params.f("size") * b.scale).max(1.0);
    if ctx.params.b("resizeLayer") && !ctx.adjustment {
        b.pad(amount.abs().ceil() as u32 + 1);
+    } else {
+        // Room for pixels displaced past the content, up to the layer's edge (#1205).
+        b.pad(crate::cover_pad(ctx, [b.img.width, b.img.height], b.offset, b.scale, amount.abs().ceil() as u32 + 1));
    }
    let off = b.to_px(ctx.params.v2("offset"));
    let oct = ctx.params.f("complexity").clamp(1.0, 10.0);
@@ -1115,6 +1120,45 @@ mod tests {
        assert_eq!(TURBULENT_PINNING[11], "Pin Left Locked");
    }

+    /// #943: every non-equivalent Evolution value renders a visibly different frame. The eased
+    /// evolution axis left 0 and 37 degrees (or 360 and 400) within a hundredth of each other.
+    #[test]
+    fn turbulent_displace_evolution_changes_the_output() {
+        // A smooth ramp (red = x, green = y) with Pin All Locked, so the frame stays opaque and
+        // the difference is purely how far the pattern moved.
+        let mut ramp = Image::new(64, 64);
+        for y in 0..64u32 {
+            for x in 0..64u32 {
+                ramp.set(x, y, [x as f32 / 63.0, y as f32 / 63.0, 0.25, 1.0]);
+            }
+        }
+        let render = |evo: f64, extra: &[(&str, Value)]| {
+            let base = [("evolution", num(evo)), ("size", num(10.0)), ("pinning", Value::Enum(8))];
+            run("ec.distort.turbulentdisplace", &[base.as_slice(), extra].concat(), ramp.clone()).img
+        };
+        let evolutions = [0.0, 37.0, 90.5, 180.0, 360.0, 400.25, 725.0, 1000.5];
+        let frames: Vec<Image> = evolutions.iter().map(|&e| render(e, &[])).collect();
+        for (i, a) in frames.iter().enumerate() {
+            for (j, b) in frames.iter().enumerate().skip(i + 1) {
+                let d = max_diff(a, b);
+                assert!(d > 0.01, "evolution {} and {} differ by only {d}", evolutions[i], evolutions[j]);
+            }
+        }
+        // Constant rate: 20 degrees next to a whole revolution (from either side) is a visible
+        // step, not the rounding-error size the eased axis gave (under 0.001).
+        assert!(max_diff(&frames[0], &render(20.0, &[])) > 0.02);
+        assert!(max_diff(&render(340.0, &[]), &frames[4]) > 0.02);
+        // 0 and 360 degrees are different frames without Cycle Evolution, and the same frame with
+        // Cycle (in Revolutions) = 1, at any starting angle.
+        assert!(max_diff(&frames[0], &frames[4]) > 0.01);
+        let cycle = [("evolutionOptions/cycleEvolution", Value::Bool(true)), ("evolutionOptions/cycle", num(1.0))];
+        assert!(max_diff(&render(0.0, &cycle), &render(360.0, &cycle)) < 1e-4);
+        assert!(max_diff(&render(37.0, &cycle), &render(397.0, &cycle)) < 1e-4);
+        assert!(max_diff(&render(0.0, &cycle), &render(37.0, &cycle)) > 0.01);
+        // Random Seed still gives a different pattern at the same Evolution.
+        assert!(max_diff(&frames[1], &render(37.0, &[("evolutionOptions/randomSeed", num(5.0))])) > 0.01);
+    }
+
    #[test]
    fn magnify_blending_none_and_scaling() {
        let img = test_img(32, 32);
@@ -292,10 +292,22 @@ pub(crate) fn fade(t: f32) -> f32 {
    t * t * t * (t * (t * 6.0 - 15.0) + 10.0)
 }

-/// 3D value noise in 0..1 (z = evolution).
+/// 3D value noise in 0..1 (z = evolution). The quintic fade applies on all three axes, so z
+/// eases in and out of every integer.
 pub fn value_noise(x: f32, y: f32, z: f32, seed: u32) -> f32 {
+    value_noise_z(x, y, z, seed, true)
+}
+
+/// [`value_noise`] with the evolution axis z interpolated linearly (x and y keep the quintic
+/// fade). The fade's zero slope at every integer z made a small Evolution change almost invisible
+/// next to a whole revolution (#943, #1816); linear z moves the pattern at a constant rate.
+pub fn value_noise_linear_z(x: f32, y: f32, z: f32, seed: u32) -> f32 {
+    value_noise_z(x, y, z, seed, false)
+}
+
+fn value_noise_z(x: f32, y: f32, z: f32, seed: u32, ease_z: bool) -> f32 {
    let (x0, y0, z0) = (x.floor(), y.floor(), z.floor());
-    let (fx, fy, fz) = (fade(x - x0), fade(y - y0), fade(z - z0));
+    let (fx, fy, fz) = (fade(x - x0), fade(y - y0), if ease_z { fade(z - z0) } else { z - z0 });
    let (ix, iy, iz) = (x0 as i32, y0 as i32, z0 as i32);
    let l = |a: f32, b: f32, t: f32| a + (b - a) * t;
    let c = |dx: i32, dy: i32, dz: i32| lattice(ix + dx, iy + dy, iz + dz, seed);
@@ -414,6 +426,27 @@ mod generator_tests {
        Image::filled(32, 32, [1.0, 0.0, 0.0, 1.0])
    }

+    /// #943: the evolution axis is linear, so z moves the noise at a constant rate, while the
+    /// classic `value_noise` keeps its eased z (other effects and their pinned goldens use it).
+    #[test]
+    fn linear_z_value_noise_moves_at_a_constant_rate() {
+        for (x, y, seed) in [(0.3f32, 0.7f32, 5u32), (2.4, -1.6, 11), (-3.1, 4.9, 0)] {
+            let a = value_noise_linear_z(x, y, 0.0, seed);
+            let b = value_noise_linear_z(x, y, 1.0, seed);
+            for z in [0.1f32, 0.25, 0.5, 0.75, 0.9] {
+                let want = a + (b - a) * z;
+                let got = value_noise_linear_z(x, y, z, seed);
+                assert!((got - want).abs() < 1e-5, "({x}, {y}) z {z}: {got} vs {want}");
+            }
+            // Same lattice values at whole z, and x / y are untouched.
+            assert_eq!(value_noise_linear_z(x, y, 2.0, seed), value_noise(x, y, 2.0, seed));
+        }
+        // The eased version still has the old shape: at z = 0.25 it lags the linear one.
+        let (a, b) = (value_noise(0.3, 0.7, 0.0, 5), value_noise(0.3, 0.7, 1.0, 5));
+        let eased = value_noise(0.3, 0.7, 0.25, 5);
+        assert!((eased - (a + (b - a) * 0.25)).abs() > 1e-3);
+    }
+
    #[test]
    fn gradient_ramp_stays_inside_the_layer_alpha() {
        // #1063: a shape's transparent pixels stay transparent; the ramp fills only the shape.
@@ -8,6 +8,7 @@

 #![deny(clippy::unwrap_used, clippy::expect_used, clippy::panic, clippy::unimplemented, clippy::todo, clippy::unreachable)]

+mod analysis_cache;
 pub mod audio_fx;
 mod blur2;
 mod blur3;
@@ -116,7 +117,7 @@ pub use ocio::color_stabilizer_maps;
 // GPU effects, part B (3D Channel, Immersive Video, colour management, simulation render passes).
 pub use channel3d::{CRYPTO_LAYERS, CryptoAux, aux_point, crypto_aux_image, crypto_aux_image_with, id_color, selection_hashes};
 pub use ocio::{ColorOp, Straight, Tf, color_program};
-pub use sim::{Acc, Blob, Bubble, Post, Shape, Sprite, SpritePlan, Tint, bubble_list, drizzle_drops, mercury_blobs, sprite_plan};
+pub use sim::{Acc, Blob, Bubble, Post, Shape, Sprite, SpritePlan, Tint, bubble_list, bubble_sample_bounds, drizzle_drops, mercury_blobs, sprite_plan};
 pub use sim2::{
    CausticsSetup, FoamDisc, FoamEnv, FoamPlan, Piece, PiecePlan, PieceTex, PixelPlan, WavePlan, Waves, caustics_setup, foam_full_plan, piece_plan, pixel_plan,
    wave_world_plan,
@@ -311,17 +312,47 @@ impl Buf {
        self.offset[0] += l as f64;
        self.offset[1] += t as f64;
    }
-    /// Grow by `pad` transparent pixels on every side.
+    /// Grow by `left` and `top` transparent pixels on those sides only.
+    pub fn grow_left_top(&mut self, left: u32, top: u32) {
+        self.pad_sides([left, top, 0, 0]);
+    }
+    /// Give the buffer the pixel-grid phase (modulo [`GRID_ALIGN`]) that [`Buf::cover`] of
+    /// `size` would, by growing left/top only ([`align_plan`]). A downscaled layer is resampled
+    /// through a pyramid whose 2x2 blocks follow the buffer's grid, so a buffer that starts at
+    /// its content's corner instead of the cover's resamples to different pixels (#1205).
+    pub fn align(&mut self, size: [f64; 2]) {
+        if let Some((l, t)) = align_plan(self.offset, self.scale, size, self.img.width, self.img.height) {
+            self.grow_left_top(l, t);
+        }
+    }
+    /// Grow by `pad` transparent pixels on every side, within [`pad_within_budget`] and as
+    /// clamped by [`Image::effective_pad`].
    pub fn pad(&mut self, pad: u32) {
-        if pad == 0 {
+        let eff = self.img.effective_pad(pad_within_budget(self.img.width, self.img.height, pad));
+        if eff == 0 {
            return;
        }
-        self.img = self.img.padded(pad);
-        self.offset[0] += pad as f64;
-        self.offset[1] += pad as f64;
+        self.img = self.img.padded(eff);
+        self.offset[0] += eff as f64;
+        self.offset[1] += eff as f64;
    }
 }

+/// `pad` on every side of a `w` × `h` effect buffer, cut so the padded buffer stays within
+/// 16 Mpx (256 MiB of f32 RGBA) or four times its own area, whichever is larger: a small layer
+/// far from an effect's centre can't ask for gigabytes (#2261). Shared with the GPU path.
+pub fn pad_within_budget(w: u32, h: u32, pad: u32) -> u32 {
+    const MIN_BUDGET: f64 = 16_777_216.0;
+    let (w, h) = (f64::from(w), f64::from(h));
+    let budget = MIN_BUDGET.max(4.0 * w * h);
+    if (w + 2.0 * f64::from(pad)) * (h + 2.0 * f64::from(pad)) <= budget {
+        return pad;
+    }
+    // (w + 2p)(h + 2p) = budget, solved for p.
+    let p = (((w - h).powi(2) + 4.0 * budget).sqrt() - (w + h)) / 4.0;
+    (p.floor().max(0.0) as u32).min(pad)
+}
+
 /// Motion Tile's output frame for a buffer with layer origin `offset` (pixels) at `scale`:
 /// `(width, height, offset)`. Output Width / Height grow (or crop) the layer rectangle about its
 /// centre, on adjustment layers too, where the rectangle is the comp's and starts at the comp
@@ -359,6 +390,33 @@ pub fn adjustment_crop(offset: [f64; 2], canvas_offset: [f64; 2], size: (u32, u3
    Some((dx as i64, dy as i64))
 }

+/// Effects that grow their own buffer by what they need (blur and glow margins, Repeat Edge
+/// Pixels through [`Buf::cover`], displacement through [`cover_pad`]): a stack of only these
+/// skips the renderer's cover of the whole layer rectangle (#1205).
+pub const SKIPS_COVER: &[&str] = &["ec.blur.gaussian", "ec.blur.fastbox", "ec.stylize.glow", "ec.distort.turbulentdisplace"];
+
+/// The grid phase [`Buf::align`] keeps and the step [`cover_pad`] grows in: covers the levels
+/// of the resampling pyramid used for downscaled layers.
+pub const GRID_ALIGN: u32 = 64;
+
+/// Left/top growth giving a buffer [`cover_plan`]'s grid phase modulo [`GRID_ALIGN`]; `None`
+/// when there is nothing to add.
+pub fn align_plan(offset: [f64; 2], scale: f64, size: [f64; 2], width: u32, height: u32) -> Option<(u32, u32)> {
+    let (dx, dy, _, _) = cover_plan(offset, scale, size, width, height)?;
+    let (l, t) = (dx % GRID_ALIGN, dy % GRID_ALIGN);
+    (l != 0 || t != 0).then_some((l, t))
+}
+
+/// Padding for an effect that moves pixels up to `want` past the content (not an adjustment
+/// layer): `want`, capped at what reaches the layer rectangle, in whole [`GRID_ALIGN`] steps so
+/// the grid phase stays. 0 once the buffer covers the layer.
+pub fn cover_pad(ctx: &EffectCtx, size: [u32; 2], offset: [f64; 2], scale: f64, want: u32) -> u32 {
+    if ctx.adjustment {
+        return 0;
+    }
+    want.min(util::layer_cover_pad(ctx, size, offset, scale)).div_ceil(GRID_ALIGN) * GRID_ALIGN
+}
+
 /// Where [`Buf::cover`] would take a buffer: shift its pixels by `(dx, dy)` and resize it to
 /// `width` × `height` so it spans the `size`-layer-pixel region that starts at its offset — the
 /// whole layer rectangle, which a sized source's buffer already is. `None` when the buffer
@@ -445,6 +503,18 @@ pub trait EffectHost: Sync {
    fn params_at(&self, _layer_time: f64) -> Option<Params> {
        None
    }
+    /// Parameter `id` (a [`flatten_params`] id such as `birthRate`) of effect `effect_index` in
+    /// the layer's stack (the running effect's [`EffectEnv::effect_index`]) at another **layer
+    /// time**: CC Particle World samples its Birth Rate at every step it simulates (#1373).
+    /// `None` when unavailable.
+    fn param_at(&self, _effect_index: usize, _id: &str, _layer_time: f64) -> Option<Value> {
+        None
+    }
+    /// Parameter `id` of effect `effect_index` has one value at every time (no keyframes, no
+    /// expression), so sampling it over time can be skipped. `false` when unknown.
+    fn param_is_static(&self, _effect_index: usize, _id: &str) -> bool {
+        false
+    }
    /// A particle simulation backend (GPU particles; see [`psim`]). `None` = simulate on the
    /// CPU.
    fn particles(&self) -> Option<&dyn psim::ParticleSim> {
@@ -525,6 +595,15 @@ pub struct EffectSpec {
    pub float: bool,
 }

+impl EffectSpec {
+    /// True when this effect grows its own buffer (blur/glow margins, Repeat Edge
+    /// [`Buf::cover`], displacement [`cover_pad`]) so a stack of only these can skip the
+    /// renderer's full-layer cover and keep the pyramid grid phase (#1205).
+    pub fn skips_cover(&self) -> bool {
+        SKIPS_COVER.contains(&self.id)
+    }
+}
+
 pub(crate) fn p(id: &'static str, name: &'static str, default: Value, ui: ParamUi) -> ParamSpec {
    ParamSpec { id, name, default, ui }
 }
@@ -1300,6 +1379,13 @@ pub fn is_time_dependent(id: &str) -> bool {
    id.starts_with("ec.sim.") || TIME_DEPENDENT.contains(&id)
 }

+/// Does effect `id` read its own parameters at earlier times (the stepped particle systems sample
+/// their Birth Rate at every step, #1373)? Caches keyed on the current values can't see what an
+/// expression returned then.
+pub fn reads_param_history(id: &str) -> bool {
+    matches!(id, "ec.sim.ccparticleworld" | "ec.sim.ccparticlesystems2" | "ec.sim.ccmrmercury")
+}
+
 /// Run an effect on a buffer.
 pub fn apply(spec: &EffectSpec, ctx: &EffectCtx, buf: Buf) -> Buf {
    (spec.render)(ctx, buf)
@@ -1324,6 +1410,23 @@ pub(crate) fn run_fx(id: &str, vals: &[(&str, Value)], img: Image, time: f64, en
 mod tests {
    use super::*;

+    /// #2261: a 20 × 20 layer with CC Radial Fast Blur's Center far away grows to at most 16 Mpx;
+    /// big layers may still grow to four times their area, and small pads are untouched.
+    #[test]
+    fn padded_buffers_stay_within_the_budget() {
+        let area = |w: u32, h: u32, p: u32| (u64::from(w) + 2 * u64::from(p)) * (u64::from(h) + 2 * u64::from(p));
+        let far = radial_fast_pad((6500.0, 6500.0), 20, 20, 0.8);
+        assert_eq!(far, 4096, "the effect asks for its full pad");
+        let mut b = Buf { img: Image::new(20, 20), offset: [0.0; 2], scale: 1.0 };
+        b.pad(far);
+        assert!(area(20, 20, 0) < area(b.img.width, b.img.height, 0) && area(b.img.width, b.img.height, 0) <= 1 << 24, "{}x{}", b.img.width, b.img.height);
+        assert_eq!(b.offset, [f64::from((b.img.width - 20) / 2); 2], "the content keeps its place");
+        let p = pad_within_budget(3840, 2160, 4096);
+        assert!(p > 1000 && area(3840, 2160, p) <= 4 * 3840 * 2160 && area(3840, 2160, p + 1) > 4 * 3840 * 2160);
+        assert_eq!(pad_within_budget(640, 360, 200), 200);
+        assert_eq!(pad_within_budget(20, 20, 0), 0);
+    }
+
    #[test]
    fn run_fx_passthrough() {
        let img = Image::filled(4, 3, [0.5, 0.25, 0.125, 1.0]);
@@ -1331,6 +1434,20 @@ mod tests {
        assert_eq!(out.img.data, img.data);
    }

+    #[test]
+    fn pad_offset_follows_the_clamped_pad() {
+        // Image::padded clamps a hostile pad to keep each side within MAX_PADDED_SIDE; the offset
+        // must move by the pad actually applied, or the content drifts from its layer position.
+        let mut img = Image::new(29_990, 2);
+        img.set(0, 0, [1.0, 0.0, 0.0, 1.0]);
+        let mut buf = Buf { img, offset: [3.0, 4.0], scale: 1.0 };
+        buf.pad(u32::MAX);
+        // Width binds: (MAX_PADDED_SIDE - 29 990) / 2 = 5.
+        assert_eq!(buf.offset, [8.0, 9.0]);
+        let (x, y) = buf.to_px([-3.0, -4.0]);
+        assert_eq!(buf.img.get(x as i64, y as i64), [1.0, 0.0, 0.0, 1.0]);
+    }
+
    #[test]
    #[ignore]
    fn dump_registry() {
@@ -1515,4 +1632,24 @@ mod tests {
        assert_eq!(g.get("noiseSourceLayerSource").map(|p| p.value.clone()), Some(Value::Enum(0)));
        assert_eq!(g.props().filter(|p| p.match_id == "noiseSourceLayerSource").count(), 1);
    }
+
+    #[test]
+    fn align_plan_is_cover_shift_mod_grid() {
+        // Content inset from the layer origin: pixel 0 maps to layer (50, 30).
+        let offset = [-50.0, -30.0];
+        let scale = 1.0;
+        let size = [1920.0, 1080.0];
+        let (dx, dy, _, _) = cover_plan(offset, scale, size, 80, 40).unwrap();
+        assert_eq!((dx, dy), (50, 30));
+        assert_eq!(align_plan(offset, scale, size, 80, 40), Some((50, 30)));
+        assert_eq!(align_plan([-64.0, -128.0], 1.0, size, 80, 40), None);
+    }
+
+    #[test]
+    fn known_margin_effects_skip_cover_and_twirl_does_not() {
+        for id in SKIPS_COVER {
+            assert!(find(id).expect(id).skips_cover(), "{id}");
+        }
+        assert!(!find("ec.distort.twirl").unwrap().skips_cover());
+    }
 }
@@ -344,6 +344,23 @@ pub fn upgrade_instance(spec: &EffectSpec, g: &mut PropGroup, ids: &mut Ids, lay
    *g != before
 }

+/// The spec id of the parameter that an instance of `spec` saved at `id` (`a/b/param`) is now:
+/// `id` itself when the spec still has it, the new id of a renamed parameter
+/// ([`PARAM_ID_ALIASES`]), or the twirl-down path of a top-level parameter that moved into a
+/// group, as [`upgrade_instance`] finds them. Returns `None` when no parameter matches.
+pub fn current_param_id(spec: &EffectSpec, id: &str) -> Option<&'static str> {
+    if let Some(ps) = spec.params.iter().find(|ps| ps.id == id) {
+        return Some(ps.id);
+    }
+    if let Some((_, _, new)) = PARAM_ID_ALIASES.iter().find(|(e, old, _)| *e == spec.id && *old == id) {
+        return Some(new);
+    }
+    if id.contains('/') {
+        return None;
+    }
+    spec.params.iter().find(|ps| ps.id.rsplit('/').next() == Some(id)).map(|ps| ps.id)
+}
+
 /// Bring an effect instance saved before project schema 2 into effect space (#227).
 ///
 /// Layers without a source rectangle (shape, text) have comp-sized effect bounds centred on
@@ -559,6 +576,21 @@ mod tests {
        assert_eq!(prop_at(&mut g, "stabilization/smoothness").unwrap().value, Value::Scalar(12.0));
    }

+    /// A saved parameter id maps to the parameter `upgrade_instance` moves it to.
+    #[test]
+    fn current_param_id_follows_renames_and_twirl_down_moves() {
+        let stab = find(crate::warp_stab::ID).unwrap();
+        assert_eq!(current_param_id(stab, "stabilization/smoothness"), Some("stabilization/smoothness"));
+        assert_eq!(current_param_id(stab, "smoothness"), Some("stabilization/smoothness"));
+        let ctc = find("ec.color.changetocolor").unwrap();
+        assert_eq!(current_param_id(ctc, "tolerance"), Some("toleranceGroup/hue"));
+        // Radio Waves' old Velocity is the growth speed, not the new Velocity.
+        let waves = find("ec.generate.radiowaves").unwrap();
+        assert_eq!(current_param_id(waves, "velocity"), Some("waveMotion/expansion"));
+        assert_eq!(current_param_id(stab, "noSuchParam"), None);
+        assert_eq!(current_param_id(stab, "other/smoothness"), None);
+    }
+
    #[test]
    fn card_wipe_back_layer_popup_becomes_a_layer_parameter() {
        let spec = find("ec.transition.cardwipe").unwrap();
@@ -34,6 +34,9 @@ fn gaussian(ctx: &EffectCtx, mut b: Buf) -> Buf {
    let repeat = ctx.params.b("repeatEdge");
    if !repeat && !ctx.adjustment {
        b.pad((s * 3.0).ceil() as u32);
+    } else if repeat && !ctx.adjustment {
+        // The edge it repeats is the layer's, not the painted content's (#1205).
+        b.cover(ctx.layer_size);
    }
    let (sx, sy) = (s * kx, s * ky);
    // Small sigmas: integer-radius box passes would step (and do nothing below ~0.6 px), so sample the kernel (#1939).
@@ -60,6 +63,9 @@ fn box_blur(ctx: &EffectCtx, mut b: Buf) -> Buf {
    if !repeat && !ctx.adjustment {
        let reach = if frac > 0.0 { r + 1 } else { r };
        b.pad((reach * it) as u32 + 1);
+    } else if repeat && !ctx.adjustment {
+        // The edge it repeats is the layer's, not the painted content's (#1205).
+        b.cover(ctx.layer_size);
    }
    let edge = repeat || ctx.adjustment;
    let lo = effectcraft_raster::box_blur(&b.img, r * kx as usize, r * ky as usize, it, edge);
@@ -264,25 +264,30 @@ pub(crate) fn sample_boxes(img: &Image, count: usize, size: usize) -> Vec<(usize
    }
    let low = Plane::luma(img);
    let step = (size / 2).max(1);
-    let mut cands: Vec<(f32, usize, usize)> = Vec::new();
-    for y in (0..=h - size).step_by(step) {
-        for x in (0..=w - size).step_by(step) {
-            // Variance of the picture inside the box (the flattest boxes hold the least detail).
-            let (mut s, mut sq, mut n, mut opaque) = (0.0f32, 0.0f32, 0.0f32, true);
-            for yy in y..y + size {
-                for xx in x..x + size {
-                    let v = low.data[yy * w + xx];
-                    s += v;
-                    sq += v * v;
-                    n += 1.0;
-                    opaque &= img.data[yy * w + xx][3] > 0.5;
+    // Candidate rows in parallel; the sort below is a total order (variance, y, x), so the
+    // result does not depend on the collection order.
+    let rows: Vec<usize> = (0..=h - size).step_by(step).collect();
+    let mut cands: Vec<(f32, usize, usize)> = rows
+        .par_iter()
+        .flat_map_iter(|&y| {
+            let data = low.data.as_slice();
+            let alpha = img.data.as_slice();
+            (0..=w - size).step_by(step).filter_map(move |x| {
+                // Variance of the picture inside the box (the flattest boxes hold the least detail).
+                let (mut s, mut sq, mut n, mut opaque) = (0.0f32, 0.0f32, 0.0f32, true);
+                for yy in y..y + size {
+                    for xx in x..x + size {
+                        let v = data[yy * w + xx];
+                        s += v;
+                        sq += v * v;
+                        n += 1.0;
+                        opaque &= alpha[yy * w + xx][3] > 0.5;
+                    }
                }
-            }
-            if opaque {
-                cands.push((sq / n - (s / n).powi(2), x, y));
-            }
-        }
-    }
+                opaque.then(|| (sq / n - (s / n).powi(2), x, y))
+            })
+        })
+        .collect();
    cands.sort_by(|a, b| a.0.total_cmp(&b.0).then(a.2.cmp(&b.2)).then(a.1.cmp(&b.1)));
    cands.into_iter().take(count).map(|(_, x, y)| (x, y, size)).collect()
 }
@@ -479,16 +484,7 @@ pub(crate) fn sampling_boxes(ctx: &EffectCtx, img: &Image, scale: f64) -> Vec<(u

 /// The grain level (0.5..2) measured in the sample boxes of `img`.
 fn grain_level(img: &Image, boxes: &[(usize, usize, usize)]) -> f32 {
-    let mut m = vec![false; img.data.len()];
-    let w = img.width as usize;
-    for &(x, y, s) in boxes {
-        for yy in y..y + s {
-            for xx in x..x + s {
-                m[yy * w + xx] = true;
-            }
-        }
-    }
-    let st = crate::noise2::grain_stats_masked(img, Some(&m));
+    let st = crate::noise2::grain_stats_boxes(img, boxes);
    let s = (st.std[0] + st.std[1] + st.std[2]) / 3.0;
    if boxes.is_empty() { 1.0 } else { (s / 0.02).clamp(0.5, 2.0) }
 }
@@ -75,6 +75,102 @@ pub(crate) fn grain_stats_masked(img: &Image, mask: Option<&[bool]>) -> GrainSta
    GrainStats { std, size: (1.0 / (1.0 - rho as f32)).clamp(0.5, 20.0) * 0.6 }
 }

+/// Grain statistics over sample `boxes` (in image pixels), measured from small crops around each
+/// box instead of the whole image. Empty `boxes` measures every opaque pixel, like
+/// [`grain_stats_masked`] without a mask. Overlapping boxes are deduplicated, so the sums match
+/// the masked version.
+pub(crate) fn grain_stats_boxes(img: &Image, boxes: &[(usize, usize, usize)]) -> GrainStats {
+    if boxes.is_empty() {
+        return grain_stats_masked(img, None);
+    }
+    let (w, h) = (img.width as usize, img.height as usize);
+    if w < 3 || h < 3 {
+        return GrainStats::default();
+    }
+    // The Gaussian's three box passes at sigma 1.5 have radius 1 each, so 3 px of halo make the
+    // residual exact inside a box; one more column covers the right neighbour used by the lag-1
+    // correlation.
+    const HALO: usize = 4;
+    let mut mask = vec![false; w * h];
+    for &(x, y, s) in boxes {
+        for yy in y..y.saturating_add(s).min(h) {
+            for xx in x..x.saturating_add(s).min(w) {
+                mask[yy * w + xx] = true;
+            }
+        }
+    }
+    let mut counted = vec![false; w * h];
+    let mut n = [0.0f64; 3];
+    let mut sum = [0.0f64; 3];
+    let mut sq = [0.0f64; 3];
+    let mut rho_num = 0.0f64;
+    let mut rho_den = 0.0f64;
+    let mut crop: Vec<([f32; 3], f32)> = Vec::new();
+    let mut planes: Vec<Plane> = Vec::new();
+    for &(bx, by, bs) in boxes {
+        let x0 = bx.saturating_sub(HALO);
+        let y0 = by.saturating_sub(HALO);
+        let x1 = bx.saturating_add(bs).saturating_add(HALO).min(w);
+        let y1 = by.saturating_add(bs).saturating_add(HALO).min(h);
+        if x1 <= x0 || y1 <= y0 {
+            continue;
+        }
+        let (cw, ch) = (x1 - x0, y1 - y0);
+        crop.clear();
+        crop.extend((y0..y1).flat_map(|y| (x0..x1).map(move |x| unpremul(img.data[y * w + x]))));
+        planes.clear();
+        for k in 0..3 {
+            let pl = Plane { w: cw, h: ch, data: crop.iter().map(|s| s.0[k]).collect() };
+            planes.push(gauss_plane(&pl, 1.5, 1.5));
+        }
+        for ly in 0..bs {
+            let y = by + ly;
+            if y >= h {
+                break;
+            }
+            for lx in 0..bs {
+                let x = bx + lx;
+                if x >= w {
+                    break;
+                }
+                let g = y * w + x;
+                if !mask[g] || counted[g] {
+                    continue;
+                }
+                counted[g] = true;
+                let l = (y - y0) * cw + (x - x0);
+                let (_, a) = crop[l];
+                if a <= 0.5 {
+                    continue;
+                }
+                for k in 0..3 {
+                    let hp = crop[l].0[k] - planes[k].data[l];
+                    sum[k] += hp as f64;
+                    sq[k] += (hp as f64) * (hp as f64);
+                    n[k] += 1.0;
+                }
+                if x + 1 < w && mask[g + 1] && crop[l + 1].1 > 0.5 {
+                    for k in 0..3 {
+                        let hp = crop[l].0[k] - planes[k].data[l];
+                        let hn = crop[l + 1].0[k] - planes[k].data[l + 1];
+                        rho_num += (hp * hn) as f64;
+                        rho_den += (hp * hp) as f64;
+                    }
+                }
+            }
+        }
+    }
+    let mut std = [0.0f32; 3];
+    for k in 0..3 {
+        if n[k] > 1.0 {
+            let mean = sum[k] / n[k];
+            std[k] = ((sq[k] / n[k] - mean * mean).max(0.0)).sqrt() as f32;
+        }
+    }
+    let rho = if rho_den > 1e-12 { (rho_num / rho_den).clamp(0.0, 0.95) } else { 0.0 };
+    GrainStats { std, size: (1.0 / (1.0 - rho as f32)).clamp(0.5, 20.0) * 0.6 }
+}
+
 /// Match Grain's Viewing Mode options.
 const MATCH_GRAIN_VIEWS: [&str; 5] = ["Preview", "Noise Samples", "Compensation Samples", "Blending Matte", "Final Output"];

@@ -86,34 +182,24 @@ fn match_grain(ctx: &EffectCtx, mut b: Buf) -> Buf {
    let view = ctx.params.e("viewingMode");
    let source = layer_or_self(ctx, &b, "noiseSourceLayer", false, false);
    let src_boxes = sampling_boxes(ctx, &source, b.scale);
-    let own_boxes = sampling_boxes(ctx, &b.img, b.scale);
    let box_col = ctx.params.get("sampling/sampleBoxColor").map(|v| v.as_color()).unwrap_or([1.0, 1.0, 0.0, 1.0]);
    if view == 1 || view == 2 {
        // Noise Samples (on the source) / Compensation Samples (on this layer).
-        let (mut img, boxes) = if view == 1 { (source, src_boxes) } else { (b.img.clone(), own_boxes) };
+        let (mut img, boxes) = if view == 1 { (source, src_boxes) } else { (b.img.clone(), sampling_boxes(ctx, &b.img, b.scale)) };
        draw_boxes(&mut img, &boxes, box_col);
        b.img = img;
        return b;
    }
-    let mask_of = |img: &Image, boxes: &[(usize, usize, usize)]| -> Option<Vec<bool>> {
-        if boxes.is_empty() {
-            return None;
-        }
-        let w = img.width as usize;
-        let mut m = vec![false; img.data.len()];
-        for &(x, y, s) in boxes {
-            for yy in y..y + s {
-                for xx in x..x + s {
-                    m[yy * w + xx] = true;
-                }
-            }
-        }
-        Some(m)
-    };
-    let src_stats = grain_stats_masked(&source, mask_of(&source, &src_boxes).as_deref());
+    let src_stats = grain_stats_boxes(&source, &src_boxes);
    let comp = (ctx.params.f("compensateForExistingNoise") / 100.0) as f32;
-    let own = if comp > 0.0 { grain_stats_masked(&b.img, mask_of(&b.img, &own_boxes).as_deref()) } else { GrainStats::default() };
-    let orig = b.img.clone();
+    // The own-layer boxes only matter for the compensation term; skip them when it is off.
+    let own = if comp > 0.0 {
+        let own_boxes = sampling_boxes(ctx, &b.img, b.scale);
+        grain_stats_boxes(&b.img, &own_boxes)
+    } else {
+        GrainStats::default()
+    };
+    let orig = (view == 0).then(|| b.img.clone());
    let look = GrainLook::from_params(ctx);
    let amp: [f32; 3] = [0, 1, 2].map(|k| {
        let s = src_stats.std[k];
@@ -147,8 +233,8 @@ fn match_grain(ctx: &EffectCtx, mut b: Buf) -> Buf {
            }
        }
    });
-    if view == 0 {
-        crate::noise::preview_compose(ctx, &mut b, &orig);
+    if let Some(orig) = &orig {
+        crate::noise::preview_compose(ctx, &mut b, orig);
    }
    b
 }
@@ -306,6 +392,63 @@ mod tests {
        img
    }

+    #[test]
+    fn boxed_grain_stats_match_the_masked_ones() {
+        // Noisy image with alpha holes; the boxes cover overlapping, edge-adjacent and
+        // bottom-right corner cases (clamped crops).
+        let mut img = noisy(64, 48, 0.2, 9);
+        for y in 0..img.height {
+            for x in 0..img.width {
+                if (x / 7 + y / 5) % 6 == 0 {
+                    let mut p = img.get(x as i64, y as i64);
+                    p[3] = 0.0;
+                    img.set(x, y, p);
+                }
+            }
+        }
+        let boxes = [(3usize, 4usize, 9usize), (8, 6, 9), (40, 20, 12), (39, 21, 12), (55, 39, 9)];
+        let w = img.width as usize;
+        let mut mask = vec![false; img.data.len()];
+        for &(x, y, s) in &boxes {
+            for yy in y..y + s {
+                for xx in x..x + s {
+                    mask[yy * w + xx] = true;
+                }
+            }
+        }
+        let masked = grain_stats_masked(&img, Some(&mask));
+        let boxed = grain_stats_boxes(&img, &boxes);
+        for k in 0..3 {
+            assert!((masked.std[k] - boxed.std[k]).abs() < 1e-6, "{k}: {masked:?} vs {boxed:?}");
+        }
+        assert!((masked.size - boxed.size).abs() <= 1e-7, "size: {masked:?} vs {boxed:?}");
+        // A denser grid where every box overlaps its neighbours (mask dedup across boxes).
+        let img2 = noisy(96, 64, 0.15, 21);
+        let mut boxes2 = Vec::new();
+        for gy in 0..5 {
+            for gx in 0..6 {
+                boxes2.push((gx * 11 + (gy % 3) * 4, gy * 10 + gx % 2, 12));
+            }
+        }
+        let w2 = img2.width as usize;
+        let mut mask2 = vec![false; img2.data.len()];
+        for &(x, y, s) in &boxes2 {
+            for yy in y..y + s {
+                for xx in x..x + s {
+                    mask2[yy * w2 + xx] = true;
+                }
+            }
+        }
+        let masked2 = grain_stats_masked(&img2, Some(&mask2));
+        let boxed2 = grain_stats_boxes(&img2, &boxes2);
+        for k in 0..3 {
+            assert!((masked2.std[k] - boxed2.std[k]).abs() < 1e-6, "{k}: {masked2:?} vs {boxed2:?}");
+        }
+        assert!((masked2.size - boxed2.size).abs() <= 1e-7, "size: {masked2:?} vs {boxed2:?}");
+        // No boxes measures the whole image, like no mask.
+        assert_eq!(grain_stats_boxes(&img, &[]), grain_stats(&img));
+    }
+
    #[test]
    fn match_grain_transfers_grain_strength() {
        let flat = Image::filled(48, 48, [0.5, 0.5, 0.5, 1.0]);
@@ -191,6 +191,11 @@ pub fn roto_data(params: &Params, layer_size: [f64; 2], f: i64, with_model: bool
 /// Seed of the chain keys: what the frames are (the Input Key), the layer size, the frame rate,
 /// the mode and the model. The prompt is in each frame's key.
 pub fn seed(params: &Params, layer_size: [f64; 2], fps: f64, model: Option<&dyn MaskModel>) -> u64 {
+    seed_of(params, layer_size, fps, model.map_or(effectcraft_segment::CLASSICAL, |m| m.info().id))
+}
+
+/// [`seed`] for the model with id `model` ([`effectcraft_segment::CLASSICAL`]: no model).
+fn seed_of(params: &Params, layer_size: [f64; 2], fps: f64, model: &str) -> u64 {
    let mut h = 0xcbf2_9ce4_8422_2325;
    fnv(&mut h, ID.as_bytes());
    fnv(&mut h, s(params, INPUT_KEY).as_bytes());
@@ -198,7 +203,7 @@ pub fn seed(params: &Params, layer_size: [f64; 2], fps: f64, model: Option<&dyn
        fnv(&mut h, &v.to_bits().to_le_bytes());
    }
    fnv(&mut h, &[tracks(params) as u8]);
-    fnv(&mut h, model.map_or(effectcraft_segment::CLASSICAL, |m| m.info().id).as_bytes());
+    fnv(&mut h, model.as_bytes());
    h
 }

@@ -255,9 +260,14 @@ pub fn frame_keys(params: &Params, layer_size: [f64; 2], fps: f64, frames: &[i64
 /// What frozen mattes depend on: what the frames are (the seed: Input Key, size, rate, mode,
 /// model), the prompt, the tracked span and the matte settings.
 pub fn frozen_key(params: &Params, layer_size: [f64; 2], fps: f64, model: Option<&dyn MaskModel>) -> String {
-    let mut h = seed(params, layer_size, fps, model);
+    frozen_key_of(params, layer_size, fps, model.map_or(effectcraft_segment::CLASSICAL, |m| m.info().id))
+}
+
+/// [`frozen_key`] for the model with id `model` ([`effectcraft_segment::CLASSICAL`]: no model).
+fn frozen_key_of(params: &Params, layer_size: [f64; 2], fps: f64, model: &str) -> String {
+    let mut h = seed_of(params, layer_size, fps, model);
    let base = reference_frame(params);
-    if let Some(st) = prompt_strokes(params, layer_size, base, model.is_some()) {
+    if let Some(st) = prompt_strokes(params, layer_size, base, model != effectcraft_segment::CLASSICAL) {
        fnv(&mut h, serde_json::to_string(&st).unwrap_or_default().as_bytes());
    }
    for v in [base, reach(params)[0], reach(params)[1]] {
@@ -273,7 +283,9 @@ pub fn is_frozen(params: &Params) -> bool {
 }

 /// Frame `f`'s frozen matte on a `w`×`h` grid, when the instance is frozen, the mattes still
-/// match ([`frozen_key`]) and `f` is one of them.
+/// match ([`frozen_key`]) and `f` is one of them. The mattes match under the session's `model`
+/// or under the model that froze them (which this session may not have loaded, e.g. a fresh
+/// headless render): frozen mattes need no segmentation.
 pub fn frozen_alpha(params: &Params, layer_size: [f64; 2], fps: f64, f: i64, w: usize, h: usize, model: Option<&dyn MaskModel>) -> Option<Vec<f32>> {
    let j = s(params, FROZEN);
    if j.is_empty() {
@@ -281,7 +293,10 @@ pub fn frozen_alpha(params: &Params, layer_size: [f64; 2], fps: f64, f: i64, w:
    }
    let fc = frozen_cache(j)?;
    if fc.key != frozen_key(params, layer_size, fps, model) {
-        return None;
+        let ids = std::iter::once(effectcraft_segment::CLASSICAL).chain(effectcraft_segment::MODELS.iter().map(|m| m.id));
+        if !ids.into_iter().any(|id| fc.key == frozen_key_of(params, layer_size, fps, id)) {
+            return None;
+        }
    }
    let fr = fc.frames.get(&f)?;
    let [fw, fh] = fc.size;
@@ -705,4 +720,28 @@ mod tests {
        p.values.insert(FROZEN.into(), Value::Str(fc2.to_json()));
        assert_eq!(frozen_alpha(&p, [100.0, 80.0], 25.0, 2, 100, 80, None), None);
    }
+
+    /// Mattes frozen with a model stay usable in a session where that model is not loaded (a
+    /// fresh headless render): they are used as stored, not re-segmented with another model.
+    #[test]
+    fn frozen_mattes_survive_a_session_without_their_model() {
+        let mut p = params(&[
+            ("objectPoint", Value::Vec2([40.0, 40.0])),
+            ("useBox", Value::Bool(true)),
+            ("boxTopLeft", Value::Vec2([10.0, 10.0])),
+            ("boxBottomRight", Value::Vec2([90.0, 70.0])),
+            ("objectTracking/framesAfter", Value::Scalar(3.0)),
+        ]);
+        p.values.insert(INPUT_KEY.into(), Value::Str("frozen-model-test".into()));
+        let stub = Stub::default();
+        let alpha: Vec<f32> = (0..100 * 80).map(|i| ((i % 100) < 50) as u8 as f32).collect();
+        let mut fc = FrozenCache { key: frozen_key(&p, [100.0, 80.0], 25.0, Some(&stub)), size: [100, 80], ..Default::default() };
+        fc.frames.insert(2, roto::freeze_frame(&alpha, &[]));
+        p.values.insert(FROZEN.into(), Value::Str(fc.to_json()));
+        assert!(is_frozen(&p));
+        assert!(frozen_alpha(&p, [100.0, 80.0], 25.0, 2, 100, 80, Some(&stub)).is_some());
+        assert_eq!(frozen_alpha(&p, [100.0, 80.0], 25.0, 2, 50, 40, None).map(|a| (a[20 * 50 + 5], a[20 * 50 + 45])), Some((1.0, 0.0)));
+        let out = run(&p, 2);
+        assert!(out.data[40 * 100 + 10][3] > 0.99 && out.data[40 * 100 + 90][3] < 0.01, "the frozen matte is used");
+    }
 }
@@ -85,21 +85,27 @@ pub trait ParticleSim: Send + Sync {
 /// (the CPU step's `carry` arithmetic, exactly). `None` when more than `cap` would be born (the
 /// CPU drops births at its live-particle cap, which an independent simulation can't know).
 pub fn births(rate: f64, steps: u64, cap: usize) -> Option<Vec<u32>> {
-    let per = rate / SPS;
-    if per * steps as f64 > cap as f64 + 2.0 {
+    if rate / SPS * steps as f64 > cap as f64 + 2.0 {
        return None;
    }
+    births_at(steps, cap, |_| rate)
+}
+
+/// [`births`] with the rate of each step, `rate(i)` particles per second during step `i` (a
+/// keyframed Birth Rate, #1373).
+pub fn births_at(steps: u64, cap: usize, rate: impl Fn(u64) -> f64) -> Option<Vec<u32>> {
    let mut out = Vec::new();
    let mut carry = 0.0f64;
    for i in 0..steps {
-        carry += per;
+        carry += rate(i) / SPS;
        let n = carry.floor() as u32;
        carry -= n as f64;
-        for _ in 0..n {
-            out.push(i as u32);
+        if n as usize > cap.saturating_sub(out.len()) {
+            return None;
        }
+        out.extend(std::iter::repeat_n(i as u32, n as usize));
    }
-    (out.len() <= cap).then_some(out)
+    Some(out)
 }

 /// Steps per second of the stepped simulations.
@@ -15,7 +15,7 @@ use effectcraft_raster::{Image, Px};
 use rayon::prelude::*;

 use crate::generate::value_noise;
-use crate::util::{SimCache, hash1, params_key, params_key_except, unpremul};
+use crate::util::{SimCache, hash1, params_key_except, unpremul};
 use crate::{Buf, EffectCtx, EffectSpec, col, num, p, popup, slider};

 mod common;
@@ -28,15 +28,18 @@ mod weather;
 pub(crate) use common::{h, hs, pct, pt, spec};
 pub use engine::particle_state;
 #[cfg(test)]
-pub(crate) use engine::{PState, PW_ANIMS, Phys, simulate};
+use engine::{MERCURY, PS2, PW_EFFECT_CAMERA, Stepped, rate_history, sim_key, simulate_rates};
 #[cfg(test)]
-use engine::{PW_EFFECT_CAMERA, sim_key};
+pub(crate) use engine::{PState, PW_ANIMS, Phys, simulate};
 pub(crate) use engine::{SPS, steps_at};
+pub(crate) use particle_fx::particle_world_textured;
 pub use particle_fx::{Blob, mercury_blobs};
+#[cfg(test)]
+use particle_fx::{PW_RATE, mercury_phys, ps2_phys, pw_phys};
 pub use registry::{specs, sprite_plan};
 pub use sprites::{Acc, Post, Shape, Sprite, SpritePlan, Tint};
 pub(crate) use sprites::{combine, raster, splat};
-pub use weather::{Bubble, bubble_list, drizzle_drops};
+pub use weather::{Bubble, bubble_list, bubble_sample_bounds, drizzle_drops};

 #[cfg(test)]
 mod tests;
@@ -1,5 +1,5 @@
 use super::common::{h, hs};
-use super::particle_fx::{PS2_CACHE, PW_CACHE, ps2_phys, pw_phys};
+use super::particle_fx::{MERCURY_CACHE, MERCURY_RATE, PS2_CACHE, PS2_RATE, PW_CACHE, PW_RATE, ps2_phys, pw_phys};
 use super::sprites::{Shape, Sprite};
 use super::{Buf, EffectCtx, Image, IntoParallelRefMutIterator, ParallelIterator, SimCache, params_key_except, value_noise};

@@ -29,6 +29,14 @@ pub(crate) struct PState {
    pub parts: Vec<Particle>,
    pub carry: f64,
    pub next_id: u32,
+    /// The birth rates of the steps so far (see [`rates_hash`]): a checkpoint is only resumed
+    /// from with the same history.
+    pub hist: u64,
+}
+
+/// `hist` after one more step at `rate` particles per second.
+fn rates_hash(hist: u64, rate: f64) -> u64 {
+    (hist ^ rate.to_bits()).wrapping_mul(0x0100_0000_01b3).rotate_left(5)
 }

 /// Physics configuration (world units; y down).
@@ -106,7 +114,15 @@ impl Phys {
        Particle { p, v, age: 0.0, life, rnd: h(id, 11, seed), id }
    }

+    /// One step at the constant [`Phys::rate`] (the tests' reference).
+    #[cfg(test)]
    pub(crate) fn step(&self, st: &mut PState, step: u64) {
+        self.step_at_rate(st, step, self.rate);
+    }
+
+    /// One step with `rate` particles per second born during it (rather than [`Phys::rate`]):
+    /// the rate only decides the births, particles already alive move and age as ever.
+    pub(crate) fn step_at_rate(&self, st: &mut PState, step: u64, rate: f64) {
        let dt = (1.0 / SPS) as f32;
        let t = step as f32 * dt;
        let mut drag = self.resistance;
@@ -164,7 +180,8 @@ impl Phys {
            q.age += dt;
        });
        st.parts.retain(|q| q.age < q.life);
-        st.carry += self.rate / SPS;
+        st.hist = rates_hash(st.hist, rate);
+        st.carry += rate / SPS;
        let n = st.carry.floor() as u32;
        st.carry -= n as f64;
        for _ in 0..n {
@@ -211,42 +228,111 @@ impl Phys {
 }

 /// The state at layer time `ctx.time` from the host's particle backend (GPU particles), or
-/// `None` (simulate on the CPU).
-pub(super) fn accelerated(ctx: &EffectCtx, key: u64, phys: &Phys) -> Option<std::sync::Arc<PState>> {
+/// `None` (simulate on the CPU). `rates`: the birth rate of each step, when it changes over time
+/// (else [`Phys::rate`]).
+pub(super) fn accelerated(ctx: &EffectCtx, key: u64, phys: &Phys, rates: Option<&[f64]>) -> Option<std::sync::Arc<PState>> {
    let backend = ctx.env.host?.particles()?;
    let steps = steps_at(ctx.time);
-    let births = crate::psim::births(phys.rate, steps, phys.max)?;
+    let births = match rates {
+        Some(r) => crate::psim::births_at(steps, phys.max, |i| r.get(i as usize).copied().unwrap_or(0.0))?,
+        None => crate::psim::births(phys.rate, steps, phys.max)?,
+    };
    let req = crate::psim::SimRequest { key, steps, births: &births, system: crate::psim::ParticleSystem::Engine(phys.desc()) };
    let parts = backend.simulate(&req)?;
    Some(std::sync::Arc::new(PState {
        parts: parts.into_iter().map(|q| Particle { p: q.p, v: q.v, age: q.age, life: q.life, rnd: q.rnd, id: q.id }).collect(),
        carry: 0.0,
        next_id: births.len() as u32,
+        hist: 0,
    }))
 }

+/// The birth rate (particles per second) of each step up to layer time `ctx.time`: parameter
+/// `id` × `k`, sampled where the step starts (a keyframed or expression-driven Birth Rate only
+/// decides the births of its own time, #1373). Without a host that evaluates the effect at
+/// other times, the current value for every step.
+pub(super) fn rate_history(ctx: &EffectCtx, id: &str, k: f64) -> Vec<f64> {
+    let now = ctx.params.f(id);
+    // A rate without keyframes or an expression is the same at every step.
+    let host = ctx.env.host.filter(|h| !h.param_is_static(ctx.env.effect_index, id));
+    (0..steps_at(ctx.time))
+        .map(|i| {
+            let v = host.and_then(|h| h.param_at(ctx.env.effect_index, id, i as f64 / SPS)).map_or(now, |v| v.as_f64());
+            if v.is_finite() { v.max(0.0) * k } else { 0.0 }
+        })
+        .collect()
+}
+
+/// Run a particle system through `rates` (one birth rate per step, see [`rate_history`]) with
+/// `cache`, resuming only from checkpoints reached with the same rates.
+pub(super) fn simulate_rates(cache: &SimCache<PState>, key: u64, phys: &Phys, rates: &[f64]) -> std::sync::Arc<PState> {
+    // `hist` of the state after each number of steps.
+    let mut prefix = Vec::with_capacity(rates.len() + 1);
+    prefix.push(0u64);
+    for r in rates {
+        prefix.push(rates_hash(prefix.last().copied().unwrap_or(0), *r));
+    }
+    let rate = |i: u64| rates.get(i as usize).copied().unwrap_or(0.0);
+    cache.run_where(key, rates.len() as u64, PState::default, |st, i| phys.step_at_rate(st, i, rate(i)), |s, st| prefix.get(s as usize) == Some(&st.hist))
+}
+
+/// A stepped particle system's particles at `ctx.time`, born at the Birth Rate of their own
+/// time (`birthRate` × `k` particles per second, see [`rate_history`]). The cache key is every
+/// parameter but Birth Rate (its history is checked through `PState::hist`) and those under
+/// `skip`, with `salt`. `gpu`: the host's particle backend may simulate it.
+pub(super) struct Stepped<'a> {
+    pub(super) cache: &'a SimCache<PState>,
+    pub(super) salt: u64,
+    pub(super) skip: &'a [&'a str],
+    pub(super) k: f64,
+    pub(super) gpu: bool,
+}
+
+impl Stepped<'_> {
+    pub(super) fn state(&self, ctx: &EffectCtx, phys: &Phys) -> std::sync::Arc<PState> {
+        let rates = rate_history(ctx, "birthRate", self.k);
+        let mut skip = self.skip.to_vec();
+        skip.push("birthRate");
+        let key = params_key_except(ctx, &Buf { img: Image::new(0, 0), offset: [0.0; 2], scale: 1.0 }, self.salt, &skip);
+        let gpu = if self.gpu { accelerated(ctx, key, phys, Some(&rates)) } else { None };
+        gpu.unwrap_or_else(|| simulate_rates(self.cache, key, phys, &rates))
+    }
+}
+
+/// CC Particle World.
+const PW: Stepped = Stepped { cache: &PW_CACHE, salt: 1, skip: &[PW_EFFECT_CAMERA], k: PW_RATE, gpu: true };
+/// CC Particle Systems II.
+pub(super) const PS2: Stepped = Stepped { cache: &PS2_CACHE, salt: 2, skip: &[], k: PS2_RATE, gpu: true };
+/// CC Mr. Mercury (its blobs are simulated on the CPU).
+pub(super) const MERCURY: Stepped = Stepped { cache: &MERCURY_CACHE, salt: 3, skip: &[], k: MERCURY_RATE, gpu: false };
+
+/// CC Particle World's particles at `ctx.time`, born at the Birth Rate of their own time.
+pub(super) fn pw_state(ctx: &EffectCtx, phys: &Phys) -> std::sync::Arc<PState> {
+    PW.state(ctx, phys)
+}
+
 /// The live particles of a stepped particle effect (`ec.sim.ccparticleworld`,
 /// `ec.sim.ccparticlesystems2`) at `ctx.time`: from the host's particle backend when it has
 /// one (GPU particles), else from the CPU simulation. For comparing the two.
 pub fn particle_state(id: &str, ctx: &EffectCtx) -> Option<Vec<crate::psim::SimParticle>> {
-    let (phys, cache, salt) = match id {
-        "ec.sim.ccparticleworld" => (pw_phys(ctx), &PW_CACHE, 1),
-        "ec.sim.ccparticlesystems2" => (ps2_phys(ctx), &PS2_CACHE, 2),
+    let st = match id {
+        "ec.sim.ccparticleworld" => pw_state(ctx, &pw_phys(ctx)),
+        "ec.sim.ccparticlesystems2" => PS2.state(ctx, &ps2_phys(ctx)),
        _ => return None,
    };
-    let key = sim_key(ctx, salt);
-    let st = accelerated(ctx, key, &phys).unwrap_or_else(|| simulate(cache, key, ctx.time, &phys));
    Some(st.parts.iter().map(|q| crate::psim::SimParticle { p: q.p, v: q.v, age: q.age, life: q.life, rnd: q.rnd, id: q.id }).collect())
 }

-/// The simulation cache key of a stepped particle effect: every parameter but CC Particle World's
-/// Effect Camera, which only changes how the particles are seen (animating it doesn't restart
-/// the simulation).
+/// The simulation cache key of a stepped particle effect at a constant Birth Rate (the tests'
+/// reference): every parameter but CC Particle World's Effect Camera.
+#[cfg(test)]
 pub(super) fn sim_key(ctx: &EffectCtx, salt: u64) -> u64 {
    params_key_except(ctx, &Buf { img: Image::new(0, 0), offset: [0.0; 2], scale: 1.0 }, salt, &[PW_EFFECT_CAMERA])
 }

-/// Run a particle system to layer time `t` through `cache`.
+/// Run a particle system at its constant [`Phys::rate`] to layer time `t` through `cache` (the
+/// tests' reference).
+#[cfg(test)]
 pub(crate) fn simulate(cache: &SimCache<PState>, key: u64, t: f64, phys: &Phys) -> std::sync::Arc<PState> {
    cache.run(key, steps_at(t), PState::default, |st, i| phys.step(st, i))
 }
@@ -1,16 +1,19 @@
-use super::engine::{PState, PW_EFFECT_CAMERA, Phys, accelerated, norm3, particle_look, sim_key, simulate, type_sprite};
-use super::sprites::{Acc, Post, Sprite, SpritePlan, raster, splat};
-use super::{Buf, EffectCtx, Image, IntoParallelRefIterator, ParallelIterator, SimCache, Value, params_key, unpremul};
+use super::engine::{MERCURY, PS2, PState, PW_EFFECT_CAMERA, Phys, norm3, particle_look, pw_state, type_sprite};
+use super::sprites::{Acc, Post, Sprite, SpritePlan, aa, raster, splat, sprite_bbox};
+use super::{Buf, EffectCtx, Image, IntoParallelRefIterator, ParallelIterator, SimCache, Value, unpremul};

 // ------------------------------------------------------------------ CC Particle World

 pub(super) static PW_CACHE: SimCache<PState> = SimCache::new(6);

+/// Particles per second per unit of CC Particle World's Birth Rate.
+pub(super) const PW_RATE: f64 = 120.0;
+
 /// CC Particle World's physics.
 pub(super) fn pw_phys(ctx: &EffectCtx) -> Phys {
    let pr = ctx.params;
    Phys {
-        rate: pr.f("birthRate").max(0.0) * 120.0,
+        rate: pr.f("birthRate").max(0.0) * PW_RATE,
        life: pr.f("longevity").max(0.0) as f32,
        producer: [pr.f("producer/producerX") as f32, pr.f("producer/producerY") as f32, pr.f("producer/producerZ") as f32],
        radius: [pr.f("producer/radiusX").max(0.0) as f32, pr.f("producer/radiusY").max(0.0) as f32, pr.f("producer/radiusZ").max(0.0) as f32],
@@ -32,20 +35,44 @@ pub(super) fn pw_phys(ctx: &EffectCtx) -> Phys {
    }
 }

+/// CC Particle World's Particle Type ▸ Textured Square.
+const PW_TEXTURED_SQUARE: u32 = 8;
+/// CC Particle World's Particle ▸ Texture ▸ Texture Layer.
+pub(super) const PW_TEXTURE_LAYER: &str = "particle/texture/textureLayer";
+
+/// Whether CC Particle World draws its Texture Layer on the particles (Textured Square with a
+/// layer chosen). Only the CPU does: `catalog::gpu_supported` keeps this case off the GPU.
+pub(crate) fn particle_world_textured(ctx: &EffectCtx) -> bool {
+    ctx.params.e("particle/particleType") == PW_TEXTURED_SQUARE && ctx.params.get(PW_TEXTURE_LAYER).and_then(Value::as_layer).is_some()
+}
+
 pub(super) fn particle_world(ctx: &EffectCtx, b: Buf) -> Buf {
+    // The texture at the current comp time, shared by every shutter sample. A layer the host
+    // can't give (the effect's own layer with its effects, a reference cycle) leaves the
+    // squares in the particle colour. Authored buffers (text, shapes) span only their content:
+    // covering the whole layer keeps the clamped sampling from stretching their edge pixels.
+    let tex = particle_world_textured(ctx).then(|| ctx.layer_param(PW_TEXTURE_LAYER, true)).flatten().map(|mut t| {
+        t.buf.cover(t.size);
+        t
+    });
+    let (w, h) = (b.img.width, b.img.height);
+    let draw = |plan: &SpritePlan| match &tex {
+        Some(t) => splat_textured(w, h, &plan.sprites, plan.acc, t),
+        None => splat(w, h, &plan.sprites, plan.acc),
+    };
    // #1195: with the comp's motion-blur shutter open, particles draw as motion trails: the
    // sprite fields of samples across the shutter are averaged, as Transform averages its
    // matrix samples. (The GPU compositor runs this case on the CPU: catalog::gpu_supported.)
    if let Some((angle, phase, n)) = ctx.env.shutter.filter(|(a, _, _)| *a > 0.0) {
        let n = (n.clamp(2, 64) as usize).max(2);
        let fd = 1.0 / ctx.fps().max(0.001);
-        let mut acc = Image::new(b.img.width, b.img.height);
+        let mut acc = Image::new(w, h);
        let mut post: Option<Post> = None;
        for k in 0..n {
            let t = ctx.time + (phase + angle * k as f64 / (n - 1) as f64) / 360.0 * fd;
            let sub = EffectCtx { params: ctx.params, time: t, layer_size: ctx.layer_size, seed: ctx.seed, adjustment: ctx.adjustment, env: ctx.env };
            if let Some(plan) = particle_world_plan(&sub, &b) {
-                let fx = splat(b.img.width, b.img.height, &plan.sprites, plan.acc);
+                let fx = draw(&plan);
                acc.data.iter_mut().zip(&fx.data).for_each(|(a, o)| (0..4).for_each(|c| a[c] += o[c]));
                post.get_or_insert(plan.post);
            }
@@ -57,11 +84,38 @@ pub(super) fn particle_world(ctx: &EffectCtx, b: Buf) -> Buf {
        };
    }
    match particle_world_plan(ctx, &b) {
-        Some(plan) => plan.finish(b),
+        Some(plan) => {
+            let fx = draw(&plan);
+            plan.finish_with(b, fx)
+        }
        None => b,
    }
 }

+/// Draw square sprites into a new transparent image of `w`×`h`, each showing the layer `tex`
+/// stretched over the square (turned with it) at the sprite's opacity.
+fn splat_textured(w: u32, hgt: u32, sprites: &[Sprite], acc: Acc, tex: &crate::LayerPixels) -> Image {
+    let mut img = Image::new(w, hgt);
+    let (tw, th) = (tex.size[0], tex.size[1]);
+    let shade = |s: &Sprite, x: f32, y: f32| {
+        // As [`sprite_shade`]'s Square, sub-pixel sprites included.
+        let (r, fade) = if s.r < 0.5 { (0.5, s.r / 0.5) } else { (s.r, 1.0) };
+        let (sn, cs) = s.rot.sin_cos();
+        let (dx, dy) = (x - s.x, y - s.y);
+        let (ux, uy) = (dx * cs + dy * sn, -dx * sn + dy * cs);
+        let e = r * 0.75;
+        let a = aa(e - ux.abs()) * aa(e - uy.abs()) * s.c[3] * fade;
+        if a <= 1e-6 {
+            return None;
+        }
+        let (u, v) = (((ux / e + 1.0) * 0.5).clamp(0.0, 1.0) as f64, ((uy / e + 1.0) * 0.5).clamp(0.0, 1.0) as f64);
+        let (px, py) = tex.buf.to_px([u * tw, v * th]);
+        Some(tex.buf.img.sample_bilinear_clamped(px, py).map(|c| c * a))
+    };
+    raster(&mut img, sprites, sprite_bbox, shade, acc);
+    img
+}
+
 /// Effect Camera ▸ FOV's default (degrees).
 pub(super) const PW_FOV: f64 = 50.0;

@@ -152,8 +206,7 @@ pub(super) fn particle_world_plan(ctx: &EffectCtx, b: &Buf) -> Option<SpritePlan
    if phys.rate <= 0.0 && ctx.time <= 0.0 {
        return None;
    }
-    let key = sim_key(ctx, 1);
-    let st = accelerated(ctx, key, &phys).unwrap_or_else(|| simulate(&PW_CACHE, key, ctx.time, &phys));
+    let st = pw_state(ctx, &phys);
    let kind = pr.e("particle/particleType");
    let birth = pr.color("particle/birthColor");
    let death = pr.color("particle/deathColor");
@@ -190,6 +243,9 @@ fn particle_sprites(sprites: Vec<Sprite>, mode: u32) -> SpritePlan {

 pub(super) static PS2_CACHE: SimCache<PState> = SimCache::new(6);

+/// Particles per second per unit of CC Particle Systems II's Birth Rate.
+pub(super) const PS2_RATE: f64 = 60.0;
+
 /// CC Particle Systems II's physics.
 pub(super) fn ps2_phys(ctx: &EffectCtx) -> Phys {
    let pr = ctx.params;
@@ -198,7 +254,7 @@ pub(super) fn ps2_phys(ctx: &EffectCtx) -> Phys {
    let pos = pr.v2("producer/position");
    let dir = (pr.f("physics/direction") as f32).to_radians();
    Phys {
-        rate: pr.f("birthRate").max(0.0) * 60.0,
+        rate: pr.f("birthRate").max(0.0) * PS2_RATE,
        life: pr.f("longevity").max(0.0) as f32,
        producer: [pos[0] as f32 / unit, pos[1] as f32 / unit, 0.0],
        radius: [pr.f("producer/radiusX").max(0.0) as f32 / unit, pr.f("producer/radiusY").max(0.0) as f32 / unit, 0.0],
@@ -225,9 +281,7 @@ pub(super) fn particle_systems2_plan(ctx: &EffectCtx, b: &Buf) -> SpritePlan {
    let pr = ctx.params;
    let lh = ctx.layer_size[1] as f32;
    let unit = lh.max(1.0);
-    let phys = ps2_phys(ctx);
-    let key = sim_key(ctx, 2);
-    let st = accelerated(ctx, key, &phys).unwrap_or_else(|| simulate(&PS2_CACHE, key, ctx.time, &phys));
+    let st = PS2.state(ctx, &ps2_phys(ctx));
    let kind = pr.e("particle/particleType");
    let birth = pr.color("particle/birthColor");
    let death = pr.color("particle/deathColor");
@@ -250,7 +304,10 @@ pub(super) fn particle_systems2_plan(ctx: &EffectCtx, b: &Buf) -> SpritePlan {

 // ------------------------------------------------------------------ CC Mr. Mercury

-static MERCURY_CACHE: SimCache<PState> = SimCache::new(6);
+pub(super) static MERCURY_CACHE: SimCache<PState> = SimCache::new(6);
+
+/// Blobs per second per unit of CC Mr. Mercury's Birth Rate.
+pub(super) const MERCURY_RATE: f64 = 10.0;

 /// A CC Mr. Mercury blob (buffer px).
 #[derive(Clone, Copy, Debug)]
@@ -260,15 +317,14 @@ pub struct Blob {
    pub r: f32,
 }

-/// CC Mr. Mercury's blobs this frame, from its particle simulation (for buffer geometry `b`).
-pub fn mercury_blobs(ctx: &EffectCtx, b: &Buf) -> Vec<Blob> {
+/// CC Mr. Mercury's physics.
+pub(super) fn mercury_phys(ctx: &EffectCtx) -> Phys {
    let pr = ctx.params;
-    let lh = ctx.layer_size[1] as f32;
-    let unit = lh.max(1.0);
+    let unit = (ctx.layer_size[1] as f32).max(1.0);
    let pos = pr.v2("producer");
    let dir = (pr.f("direction") as f32).to_radians();
-    let phys = Phys {
-        rate: pr.f("birthRate").max(0.0) * 10.0,
+    Phys {
+        rate: pr.f("birthRate").max(0.0) * MERCURY_RATE,
        life: pr.f("longevity").max(0.0) as f32,
        producer: [pos[0] as f32 / unit, pos[1] as f32 / unit, 0.0],
        radius: [pr.f("radiusX").max(0.0) as f32 / unit, pr.f("radiusY").max(0.0) as f32 / unit, 0.0],
@@ -282,8 +338,15 @@ pub fn mercury_blobs(ctx: &EffectCtx, b: &Buf) -> Vec<Blob> {
        seed: ctx.seed.wrapping_mul(0xc2b2ae35),
        max: 4_000,
        flat: true,
-    };
-    let st = simulate(&MERCURY_CACHE, params_key(ctx, &Buf { img: Image::new(0, 0), offset: [0.0; 2], scale: 1.0 }, 3), ctx.time, &phys);
+    }
+}
+
+/// CC Mr. Mercury's blobs this frame, from its particle simulation (for buffer geometry `b`).
+pub fn mercury_blobs(ctx: &EffectCtx, b: &Buf) -> Vec<Blob> {
+    let pr = ctx.params;
+    let unit = (ctx.layer_size[1] as f32).max(1.0);
+    let phys = mercury_phys(ctx);
+    let st = MERCURY.state(ctx, &phys);
    let (bs, ds) = (pr.f("blobBirthSize") as f32, pr.f("blobDeathSize") as f32);
    let s = b.scale as f32;
    st.parts
@@ -1,6 +1,6 @@
 use super::common::{pct, pt, spec};
 use super::engine::{PARTICLE_TYPES, PW_ANIMS};
-use super::particle_fx::{PW_FOV, mr_mercury, particle_systems2, particle_systems2_plan, particle_world, particle_world_plan};
+use super::particle_fx::{PW_FOV, PW_TEXTURE_LAYER, mr_mercury, particle_systems2, particle_systems2_plan, particle_world, particle_world_plan};
 use super::sprites::SpritePlan;
 use super::weather::{bubbles, drizzle, rainfall, rainfall_plan, snowfall, snowfall_plan, star_burst, star_burst_plan};
 use super::{Buf, EffectCtx, EffectSpec, ParamUi, Value, col, num, p, popup, slider};
@@ -151,6 +151,7 @@ pub fn specs() -> Vec<EffectSpec> {
                p("physics/gravityVector/gravityY", "Gravity Y", num(1.0), slider(-1.0, 1.0, -1.0, 1.0, 2)),
                p("physics/gravityVector/gravityZ", "Gravity Z", num(0.0), slider(-1.0, 1.0, -1.0, 1.0, 2)),
                p("particle/particleType", "Particle Type", Value::Enum(0), popup(PARTICLE_TYPES)),
+                p(PW_TEXTURE_LAYER, "Texture Layer", Value::Layer(None), ParamUi::Layer),
                p("particle/birthSize", "Birth Size", num(0.2), slider(0.0, 10.0, 0.0, 1.0, 3)),
                p("particle/deathSize", "Death Size", num(0.2), slider(0.0, 10.0, 0.0, 1.0, 3)),
                p("particle/sizeVariation", "Size Variation", num(0.0), pct()),
@@ -225,7 +225,7 @@ impl Post {
    }
 }

-fn sprite_bbox(s: &Sprite) -> Option<[f32; 4]> {
+pub(super) fn sprite_bbox(s: &Sprite) -> Option<[f32; 4]> {
    if s.c[3] <= 1e-5 || s.r <= 0.0 {
        return None;
    }
@@ -97,6 +97,60 @@ fn bubbles_rise() {
    assert!(y0 >= 0.0 && y1 >= 0.0 && (y1 < y0 || y0 < 8.0), "{y0} -> {y1}");
 }

+/// #2024: bubbles near the layer's edges show its edge pixels, not the pale colour that stands
+/// in for transparent ones.
+#[test]
+fn bubbles_near_edges_show_the_layer() {
+    let blue = Image::filled(40, 40, [0.0, 0.0, 1.0, 1.0]);
+    let pale = [0, 1].map(|reflection| {
+        let vals = [("bubbleAmount", num(200.0)), ("bubbleSize", num(3.0)), ("reflectionType", Value::Enum(reflection))];
+        let a = run("ec.sim.ccbubbles", &vals, blue.clone(), 0.3);
+        assert!(a.data.iter().any(|p| p[3] > 0.5), "bubbles drawn");
+        // Blue plus the white highlight keeps blue − red = alpha; the pale colour leaves 0.2 · alpha.
+        a.data.iter().filter(|p| (p[2] - p[0] - p[3]).abs() > 1e-4).count()
+    });
+    assert_eq!(pale, [0, 0], "pale bubble pixels (liquid, metal)");
+}
+
+/// CC Bubbles on a 40 × 40 layer `img` at `scale`, in a buffer padded by 6 transparent pixels
+/// (a half-resolution preview's layout).
+fn padded_bubbles(img: Image, scale: f64, reflection: u32) -> Image {
+    let size = 40.0;
+    let s = crate::find("ec.sim.ccbubbles").unwrap();
+    let mut params = crate::Params { values: s.params.iter().map(|p| (p.id.to_string(), crate::default_value(p, [size; 2]))).collect() };
+    for (k, v) in [("bubbleAmount", num(200.0)), ("bubbleSize", num(3.0)), ("reflectionType", Value::Enum(reflection))] {
+        params.values.insert(k.into(), v);
+    }
+    let ctx = EffectCtx { params: &params, time: 0.3, layer_size: [size; 2], seed: 1, adjustment: false, env: EffectEnv::default() };
+    let mut b = Buf { img, offset: [0.0; 2], scale };
+    b.pad(6);
+    crate::apply(s, &ctx, b).img
+}
+
+/// #2024: the same when the buffer has transparent padding around the layer: samples past the
+/// layer's edges repeat its edge pixels, not the padding, and a clear hole inside the layer is
+/// still refracted as the pale colour.
+#[test]
+fn bubbles_near_padded_edges_show_the_layer() {
+    let blue = |side| Image::filled(side, side, [0.0, 0.0, 1.0, 1.0]);
+    let pale = |img: &Image| img.data.iter().filter(|p| (p[2] - p[0] - p[3]).abs() > 1e-4).count();
+    for (scale, side) in [(1.0, 40), (0.5, 20)] {
+        let counts = [0, 1].map(|reflection| {
+            let a = padded_bubbles(blue(side), scale, reflection);
+            assert!(a.data.iter().any(|p| p[3] > 0.5), "bubbles drawn");
+            pale(&a)
+        });
+        assert_eq!(counts, [0, 0], "pale bubble pixels at scale {scale} (liquid, metal)");
+    }
+    let mut holed = blue(40);
+    for y in 12..28 {
+        for x in 12..28 {
+            holed.set(x, y, [0.0; 4]);
+        }
+    }
+    assert!(pale(&padded_bubbles(holed, 1.0, 0)) > 0, "the hole refracts as the pale colour");
+}
+
 #[test]
 fn drizzle_ripples() {
    let a = run("ec.sim.ccdrizzle", &[], ramp(48, 48), 0.6);
@@ -329,6 +383,110 @@ fn particle_world_effect_camera() {
    assert_ne!(key(&params), key(&moved));
 }

+/// A host whose every layer is `img`.
+struct TexHost(Image);
+impl crate::EffectHost for TexHost {
+    fn layer(&self, _: u64, _: bool) -> Option<crate::LayerPixels> {
+        let s = [self.0.width as f64, self.0.height as f64];
+        Some(crate::LayerPixels { buf: Buf { img: self.0.clone(), offset: [0.0; 2], scale: 1.0 }, size: s })
+    }
+    fn audio(&self, _: u64, _: f64, _: usize, _: u32) -> Option<Vec<f32>> {
+        None
+    }
+}
+
+/// A texture whose left half is green and right half blue.
+fn two_tone_tex() -> Image {
+    let mut tex = Image::new(8, 8);
+    for y in 0..8 {
+        for x in 0..8 {
+            tex.set(x, y, if x < 4 { [0.0, 1.0, 0.0, 1.0] } else { [0.0, 0.0, 1.0, 1.0] });
+        }
+    }
+    tex
+}
+
+/// CC Particle World drawing red Textured Squares with Texture Layer `layer`.
+fn pw_textured_vals(layer: Option<u64>) -> Vec<(&'static str, Value)> {
+    vec![
+        ("birthRate", num(1.0)),
+        ("extras/randomSeed", num(4.0)),
+        ("particle/particleType", Value::Enum(8)),
+        ("particle/texture/textureLayer", Value::Layer(layer)),
+        ("particle/birthSize", num(1.0)),
+        ("particle/deathSize", num(1.0)),
+        ("particle/birthColor", col(1.0, 0.0, 0.0)),
+        ("particle/deathColor", col(1.0, 0.0, 0.0)),
+    ]
+}
+
+/// #1465: Textured Square draws the Texture Layer on each particle, not the particle colour.
+#[test]
+fn particle_world_textured_square_draws_the_texture_layer() {
+    let host = TexHost(two_tone_tex());
+    let vals = pw_textured_vals;
+    let env = EffectEnv { host: Some(&host), ..Default::default() };
+    let out = run_fx("ec.sim.ccparticleworld", &vals(Some(1)), Image::new(48, 48), 1.0, env).img;
+    let seen: Vec<_> = out.data.iter().filter(|p| p[3] > 0.05).collect();
+    assert!(!seen.is_empty(), "particles drawn");
+    assert!(seen.iter().all(|p| p[0] < 0.02 * p[3]), "no particle colour: {:?}", seen.iter().find(|p| p[0] >= 0.02 * p[3]));
+    // Both halves of the texture show: it is mapped across the square, not sampled once.
+    assert!(seen.iter().any(|p| p[1] > 2.0 * p[2]) && seen.iter().any(|p| p[2] > 2.0 * p[1]), "both texture halves");
+    // Without a texture layer the squares keep the particle colour.
+    let plain = run_fx("ec.sim.ccparticleworld", &vals(None), Image::new(48, 48), 1.0, env).img;
+    assert!(plain.data.iter().any(|p| p[3] > 0.05 && p[0] > 0.9 * p[3]));
+}
+
+/// #1465 with #1195's motion trails: with the shutter open the averaged samples still show
+/// the Texture Layer, not the particle colour.
+#[test]
+fn particle_world_textured_square_motion_trails_draw_the_texture_layer() {
+    let host = TexHost(two_tone_tex());
+    let env = EffectEnv { host: Some(&host), frame_rate: 10.0, shutter: Some((360.0, -180.0, 8)), ..Default::default() };
+    let blurred = run_fx("ec.sim.ccparticleworld", &pw_textured_vals(Some(1)), Image::new(48, 48), 1.0, env).img;
+    let sharp = run_fx("ec.sim.ccparticleworld", &pw_textured_vals(Some(1)), Image::new(48, 48), 1.0, EffectEnv { shutter: None, ..env }).img;
+    assert_ne!(sharp.data, blurred.data, "the shutter smears the particles");
+    let seen: Vec<_> = blurred.data.iter().filter(|p| p[3] > 0.02).collect();
+    assert!(!seen.is_empty(), "particles drawn");
+    assert!(seen.iter().all(|p| p[0] < 0.02 * p[3]), "no particle colour: {:?}", seen.iter().find(|p| p[0] >= 0.02 * p[3]));
+    assert!(seen.iter().any(|p| p[1] > 2.0 * p[2]) && seen.iter().any(|p| p[2] > 2.0 * p[1]), "both texture halves");
+}
+
+/// A host whose every layer is `0` as given (a buffer that may span only its content).
+struct PixelsHost(crate::LayerPixels);
+impl crate::EffectHost for PixelsHost {
+    fn layer(&self, _: u64, _: bool) -> Option<crate::LayerPixels> {
+        Some(self.0.clone())
+    }
+    fn audio(&self, _: u64, _: f64, _: usize, _: u32) -> Option<Vec<f32>> {
+        None
+    }
+}
+
+/// #1465: a Texture Layer whose buffer spans only its content (text, shapes) is mapped as
+/// the whole layer, transparent around the content, not with its edge pixels stretched.
+#[test]
+fn particle_world_texture_layer_with_a_content_sized_buffer() {
+    // An 8×8 layer with a green 4×4 square in the middle: once as the full layer, once as
+    // just the square's pixels.
+    let mut full = Image::new(8, 8);
+    for y in 2..6 {
+        for x in 2..6 {
+            full.set(x, y, [0.0, 1.0, 0.0, 1.0]);
+        }
+    }
+    let content = Image::filled(4, 4, [0.0, 1.0, 0.0, 1.0]);
+    let render = |buf: Buf| {
+        let host = PixelsHost(crate::LayerPixels { buf, size: [8.0, 8.0] });
+        let env = EffectEnv { host: Some(&host), ..Default::default() };
+        run_fx("ec.sim.ccparticleworld", &pw_textured_vals(Some(1)), Image::new(48, 48), 1.0, env).img
+    };
+    let want = render(Buf { img: full, offset: [0.0; 2], scale: 1.0 });
+    let got = render(Buf { img: content, offset: [-2.0, -2.0], scale: 1.0 });
+    assert!(want.data.iter().any(|p| p[3] > 0.05), "particles drawn");
+    assert_eq!(want.data, got.data, "the content-sized buffer draws as the full layer");
+}
+
 #[test]
 fn particle_systems2_seek_and_direction() {
    let v = vec![
@@ -405,3 +563,266 @@ fn half_resolution_scales_sprites() {
    let sum = |i: &Image| i.data.iter().map(|p| p[0]).sum::<f32>() / i.data.len() as f32;
    assert!((sum(&full.img) - sum(&half.img)).abs() < 0.05, "{} {}", sum(&full.img), sum(&half.img));
 }
+
+// ---------------------------------------------------------- Birth Rate over time (#1373)
+
+/// A host that evaluates effect `index`'s Birth Rate at other layer times as `rate(t)`.
+struct Rate {
+    index: usize,
+    rate: fn(f64) -> f64,
+}
+impl crate::EffectHost for Rate {
+    fn layer(&self, _: u64, _: bool) -> Option<crate::LayerPixels> {
+        None
+    }
+    fn audio(&self, _: u64, _: f64, _: usize, _: u32) -> Option<Vec<f32>> {
+        None
+    }
+    fn param_at(&self, effect_index: usize, id: &str, t: f64) -> Option<Value> {
+        (effect_index == self.index && id == "birthRate").then(|| num((self.rate)(t)))
+    }
+}
+
+/// Birth Rate 3 until 0.5 s, then 0 (the issue's one-shot burst).
+fn burst(t: f64) -> f64 {
+    if t < 0.5 { 3.0 } else { 0.0 }
+}
+
+/// The same burst, cut at 0.25 s (an earlier key moved).
+fn short_burst(t: f64) -> f64 {
+    if t < 0.25 { 3.0 } else { 0.0 }
+}
+
+/// Birth Rate falling linearly from 3 at 0 s to 0 at 0.5 s.
+fn falling(t: f64) -> f64 {
+    (3.0 * (1.0 - t / 0.5)).max(0.0)
+}
+
+/// CC Particle World's parameters: random seed `seed`, Birth Rate `now` (its value at the
+/// rendered time), Longevity 1 s.
+fn pw_params(seed: f64, now: f64) -> crate::Params {
+    let spec = crate::find("ec.sim.ccparticleworld").unwrap();
+    let mut p = crate::Params { values: spec.params.iter().map(|ps| (ps.id.to_string(), crate::default_value(ps, [100.0, 100.0]))).collect() };
+    for (k, v) in [("birthRate", num(now)), ("extras/randomSeed", num(seed)), ("longevity", num(1.0))] {
+        p.values.insert(k.to_string(), v);
+    }
+    p
+}
+
+fn pw_ctx<'a>(p: &'a crate::Params, t: f64, host: Option<&'a Rate>, index: usize) -> EffectCtx<'a> {
+    let env = EffectEnv { host: host.map(|h| h as &dyn crate::EffectHost), effect_index: index, ..Default::default() };
+    EffectCtx { params: p, time: t, layer_size: [100.0, 100.0], seed: 1, adjustment: false, env }
+}
+
+/// The live particles at layer time `t` with Birth Rate `now` there and `host`'s history.
+fn pw_at(seed: f64, now: f64, t: f64, host: Option<&Rate>) -> Vec<crate::psim::SimParticle> {
+    let p = pw_params(seed, now);
+    particle_state("ec.sim.ccparticleworld", &pw_ctx(&p, t, host, host.map_or(0, |h| h.index))).unwrap()
+}
+
+/// The same, simulated from layer time 0 with a cache of its own (the reference).
+fn pw_fresh(seed: f64, now: f64, t: f64, host: &Rate) -> Vec<crate::psim::SimParticle> {
+    let p = pw_params(seed, now);
+    let ctx = pw_ctx(&p, t, Some(host), host.index);
+    let key = params_key_except(&ctx, &Buf { img: Image::new(0, 0), offset: [0.0; 2], scale: 1.0 }, 1, &[PW_EFFECT_CAMERA, "birthRate"]);
+    let st = simulate_rates(&SimCache::new(1), key, &pw_phys(&ctx), &rate_history(&ctx, "birthRate", PW_RATE));
+    st.parts.iter().map(|q| crate::psim::SimParticle { p: q.p, v: q.v, age: q.age, life: q.life, rnd: q.rnd, id: q.id }).collect()
+}
+
+/// Particles born in the first `t` seconds of `rate`.
+fn born_by(rate: fn(f64) -> f64, t: f64) -> usize {
+    crate::psim::births_at(steps_at(t), 40_000, |i| rate(i as f64 / SPS) * PW_RATE).unwrap().len()
+}
+
+/// #1373: Birth Rate only decides the births of its own time. After a burst stops, the
+/// particles born in it live on (moving and ageing) until their Longevity runs out, rather
+/// than vanishing because the rate is now 0.
+#[test]
+fn a_burst_lives_on_after_birth_rate_drops_to_zero() {
+    let host = Rate { index: 2, rate: burst };
+    // During the burst: as a constant Birth Rate of 3.
+    assert_eq!(pw_at(101.0, 3.0, 0.4, Some(&host)), pw_at(101.0, 3.0, 0.4, None));
+    // After it: the burst's particles, none newer.
+    let late = pw_at(101.0, 0.0, 0.9, Some(&host));
+    let n = born_by(burst, 0.5);
+    assert!(late.len() > n / 2 && late.iter().all(|q| (q.id as usize) < n), "{} live of {n} born", late.len());
+    assert!(pw_at(101.0, 0.0, 0.9, None).is_empty(), "a constant Birth Rate of 0 never bore any");
+    // They keep moving.
+    let early = pw_at(101.0, 0.0, 0.7, Some(&host));
+    let q0 = early.iter().find(|q| q.id == late[0].id).unwrap();
+    assert!(q0.p != late[0].p && late[0].age > q0.age + 0.19, "{q0:?} -> {:?}", late[0]);
+    // Longevity 1 s (± 20 %): all gone by 1.8 s.
+    assert!(pw_at(101.0, 0.0, 1.8, Some(&host)).is_empty());
+    // The effect asks for its own index: another effect's history isn't its own.
+    let p = pw_params(101.0, 0.0);
+    assert!(particle_state("ec.sim.ccparticleworld", &pw_ctx(&p, 0.9, Some(&host), 0)).unwrap().is_empty());
+}
+
+/// A Birth Rate ramping down isn't simulated as if its current value had always applied.
+#[test]
+fn a_ramped_birth_rate_bears_what_each_moment_asked_for() {
+    let host = Rate { index: 0, rate: falling };
+    let ramped = pw_at(102.0, falling(0.25), 0.25, Some(&host));
+    let constant = pw_at(102.0, falling(0.25), 0.25, None);
+    assert_eq!(ramped.len(), born_by(falling, 0.25), "every particle born so far is alive");
+    assert_eq!(constant.len(), born_by(|_| 1.5, 0.25));
+    assert!(ramped.len() > constant.len() + 10, "{} vs {}", ramped.len(), constant.len());
+}
+
+/// Seeking backward, forward and to the same time again gives the state simulated from 0.
+#[test]
+fn seeking_through_a_birth_rate_history_matches_simulating_from_zero() {
+    let host = Rate { index: 0, rate: burst };
+    for t in [1.4, 0.6, 0.9, 0.3, 0.9, 1.1] {
+        let now = burst(t);
+        assert_eq!(pw_at(103.0, now, t, Some(&host)), pw_fresh(103.0, now, t, &host), "at {t}");
+    }
+}
+
+/// The simulation cache key leaves Birth Rate out (so an animated rate keeps its checkpoints),
+/// but a checkpoint is only resumed with the history that reached it: after an earlier key
+/// moves, the same current rate (0) gives the new history's particles.
+#[test]
+fn an_earlier_birth_rate_change_is_not_served_from_stale_checkpoints() {
+    let (long, short) = (Rate { index: 0, rate: burst }, Rate { index: 0, rate: short_burst });
+    let a = pw_at(104.0, 0.0, 0.9, Some(&long));
+    let b = pw_at(104.0, 0.0, 0.9, Some(&short));
+    assert_eq!(b, pw_fresh(104.0, 0.0, 0.9, &short));
+    assert!(b.len() < a.len() && !b.is_empty(), "{} vs {}", b.len(), a.len());
+    assert_eq!(pw_at(104.0, 0.0, 1.0, Some(&long)), pw_fresh(104.0, 0.0, 1.0, &long));
+}
+
+/// A constant Birth Rate gives exactly the particles it did before the history was sampled.
+#[test]
+fn a_constant_birth_rate_is_unchanged() {
+    let host = Rate { index: 0, rate: |_| 2.0 };
+    let p = pw_params(105.0, 2.0);
+    let ctx = pw_ctx(&p, 1.3, None, 0);
+    let phys = pw_phys(&ctx);
+    let before = simulate(&SimCache::new(1), sim_key(&ctx, 1), 1.3, &phys);
+    let now = pw_at(105.0, 2.0, 1.3, Some(&host));
+    assert_eq!(now.len(), before.parts.len());
+    assert!(now.iter().zip(&before.parts).all(|(a, b)| a.id == b.id && a.p == b.p && a.v == b.v && a.age == b.age));
+    assert_eq!(crate::psim::births_at(78, 40_000, |_| phys.rate), crate::psim::births(phys.rate, 78, 40_000));
+}
+
+/// The GPU's birth schedule for a rate history is the CPU's: the ids born are the ids the
+/// CPU simulation numbers.
+#[test]
+fn the_birth_schedule_follows_the_rate_history() {
+    let host = Rate { index: 0, rate: falling };
+    let p = pw_params(106.0, 0.0);
+    let ctx = pw_ctx(&p, 0.7, Some(&host), 0);
+    let rates = rate_history(&ctx, "birthRate", PW_RATE);
+    let st = simulate_rates(&SimCache::new(1), 9, &pw_phys(&ctx), &rates);
+    let births = crate::psim::births_at(rates.len() as u64, 40_000, |i| rates[i as usize]).unwrap();
+    assert_eq!(st.next_id as usize, births.len());
+    assert!(births.iter().all(|&b| f64::from(b) / SPS < 0.5), "nothing born once the ramp reaches 0");
+}
+
+// ------------------------- CC Particle Systems II and CC Mr. Mercury's Birth Rate over time
+
+/// A stepped particle effect: its id, physics and simulation.
+struct System {
+    id: &'static str,
+    phys: fn(&EffectCtx) -> Phys,
+    stepped: Stepped<'static>,
+}
+
+const SYSTEMS: [System; 2] =
+    [System { id: "ec.sim.ccparticlesystems2", phys: ps2_phys, stepped: PS2 }, System { id: "ec.sim.ccmrmercury", phys: mercury_phys, stepped: MERCURY }];
+
+/// `id`'s parameters with Birth Rate `now` and Longevity 1 s.
+fn sys_params(id: &str, now: f64) -> crate::Params {
+    let spec = crate::find(id).unwrap();
+    let mut p = crate::Params { values: spec.params.iter().map(|ps| (ps.id.to_string(), crate::default_value(ps, [100.0, 100.0]))).collect() };
+    for (k, v) in [("birthRate", num(now)), ("longevity", num(1.0))] {
+        assert!(p.values.contains_key(k), "{id}: no {k}");
+        p.values.insert(k.to_string(), v);
+    }
+    p
+}
+
+/// The context at layer time `t` (`seed` keeps each test's simulations apart).
+fn sys_ctx<'a>(p: &'a crate::Params, t: f64, host: Option<&'a Rate>, seed: u32) -> EffectCtx<'a> {
+    let env = EffectEnv { host: host.map(|h| h as &dyn crate::EffectHost), effect_index: host.map_or(0, |h| h.index), ..Default::default() };
+    EffectCtx { params: p, time: t, layer_size: [100.0, 100.0], seed, adjustment: false, env }
+}
+
+/// The live particles (id, position, age) of `sys` at `t` through its simulation.
+fn sys_at(sys: &System, seed: u32, now: f64, t: f64, host: Option<&Rate>) -> Vec<(u32, [f32; 3], f32)> {
+    let p = sys_params(sys.id, now);
+    let ctx = sys_ctx(&p, t, host, seed);
+    sys.stepped.state(&ctx, &(sys.phys)(&ctx)).parts.iter().map(|q| (q.id, q.p, q.age)).collect()
+}
+
+/// The same, simulated from layer time 0 with a cache of its own (the reference).
+fn sys_fresh(sys: &System, seed: u32, now: f64, t: f64, host: &Rate) -> Vec<(u32, [f32; 3], f32)> {
+    let p = sys_params(sys.id, now);
+    let ctx = sys_ctx(&p, t, Some(host), seed);
+    let mut skip = sys.stepped.skip.to_vec();
+    skip.push("birthRate");
+    let key = params_key_except(&ctx, &Buf { img: Image::new(0, 0), offset: [0.0; 2], scale: 1.0 }, sys.stepped.salt, &skip);
+    let st = simulate_rates(&SimCache::new(1), key, &(sys.phys)(&ctx), &rate_history(&ctx, "birthRate", sys.stepped.k));
+    st.parts.iter().map(|q| (q.id, q.p, q.age)).collect()
+}
+
+/// What `sys` draws at `t`: CC Particle Systems II's particles, CC Mr. Mercury's blobs.
+fn sys_drawn(sys: &System, seed: u32, now: f64, t: f64, host: Option<&Rate>) -> usize {
+    let p = sys_params(sys.id, now);
+    let ctx = sys_ctx(&p, t, host, seed);
+    match sys.id {
+        "ec.sim.ccmrmercury" => mercury_blobs(&ctx, &Buf { img: Image::new(100, 100), offset: [0.0; 2], scale: 1.0 }).len(),
+        id => particle_state(id, &ctx).unwrap().len(),
+    }
+}
+
+/// #1373 for CC Particle Systems II and CC Mr. Mercury: a burst lives on after Birth Rate
+/// drops to 0 (what they draw too), moving and ageing, and is gone after its Longevity.
+#[test]
+fn particle_systems_ii_and_mr_mercury_keep_a_burst_after_birth_rate_drops() {
+    let host = Rate { index: 1, rate: burst };
+    for sys in &SYSTEMS {
+        let born = crate::psim::births_at(steps_at(0.5), 40_000, |i| burst(i as f64 / SPS) * sys.stepped.k).unwrap().len();
+        assert_eq!(sys_at(sys, 201, 3.0, 0.4, Some(&host)), sys_at(sys, 201, 3.0, 0.4, None), "{}: during the burst", sys.id);
+        let late = sys_at(sys, 201, 0.0, 0.9, Some(&host));
+        assert!(late.len() > born / 2 && late.iter().all(|q| (q.0 as usize) < born), "{}: {} live of {born}", sys.id, late.len());
+        assert!(sys_drawn(sys, 201, 0.0, 0.9, Some(&host)) > 0, "{}: drawn", sys.id);
+        assert_eq!(sys_drawn(sys, 201, 0.0, 0.9, None), 0, "{}: a constant 0 bore none", sys.id);
+        let early = sys_at(sys, 201, 0.0, 0.7, Some(&host));
+        let q0 = early.iter().find(|q| q.0 == late[0].0).unwrap();
+        assert!(q0.1 != late[0].1 && late[0].2 > q0.2 + 0.19, "{}: {q0:?} -> {:?}", sys.id, late[0]);
+        assert!(sys_at(sys, 201, 0.0, 1.8, Some(&host)).is_empty(), "{}: gone after Longevity", sys.id);
+    }
+}
+
+/// Seeking matches a simulation from 0, and moving an earlier key (same current rate, same
+/// cache key) isn't served from the old history's checkpoints.
+#[test]
+fn particle_systems_ii_and_mr_mercury_seek_and_drop_stale_checkpoints() {
+    let (long, short) = (Rate { index: 0, rate: burst }, Rate { index: 0, rate: short_burst });
+    for sys in &SYSTEMS {
+        for t in [1.4, 0.6, 0.9, 0.3, 0.9, 1.1] {
+            let now = burst(t);
+            assert_eq!(sys_at(sys, 202, now, t, Some(&long)), sys_fresh(sys, 202, now, t, &long), "{} at {t}", sys.id);
+        }
+        let b = sys_at(sys, 202, 0.0, 0.9, Some(&short));
+        assert_eq!(b, sys_fresh(sys, 202, 0.0, 0.9, &short), "{}: the moved key", sys.id);
+        assert!(!b.is_empty() && b.len() < sys_at(sys, 202, 0.0, 0.9, Some(&long)).len(), "{}", sys.id);
+    }
+}
+
+/// A constant Birth Rate gives exactly the particles the constant-rate simulation did.
+#[test]
+fn particle_systems_ii_and_mr_mercury_are_unchanged_at_a_constant_rate() {
+    let host = Rate { index: 0, rate: |_| 2.0 };
+    for sys in &SYSTEMS {
+        let p = sys_params(sys.id, 2.0);
+        let ctx = sys_ctx(&p, 1.3, None, 203);
+        let before = simulate(&SimCache::new(1), 1, 1.3, &(sys.phys)(&ctx));
+        let before: Vec<_> = before.parts.iter().map(|q| (q.id, q.p, q.age)).collect();
+        assert!(!before.is_empty());
+        assert_eq!(sys_at(sys, 203, 2.0, 1.3, Some(&host)), before, "{}: keyed to a constant", sys.id);
+        assert_eq!(sys_at(sys, 203, 2.0, 1.3, None), before, "{}: no host", sys.id);
+    }
+}
@@ -1,6 +1,7 @@
 use super::common::{h, hs};
 use super::sprites::{Acc, Post, Shape, Sprite, SpritePlan, Tint, aa, raster};
 use super::{Buf, EffectCtx, Image, IntoParallelIterator, ParallelIterator, unpremul};
+use crate::util::layer_rect_at;

 // ------------------------------------------------------------------ CC Rainfall / CC Snowfall

@@ -160,11 +161,21 @@ pub fn bubble_list(ctx: &EffectCtx, b: &Buf) -> Vec<Bubble> {
        .collect()
 }

+/// CC Bubbles' refraction sample bounds in the pixels of a buffer with `offset` and `scale`: the
+/// layer rectangle's first and last pixel centres (x0, y0, x1, y1). Samples clamped to them repeat
+/// the layer's edge pixels instead of reaching transparent padding around it (#2024).
+pub fn bubble_sample_bounds(ctx: &EffectCtx, offset: [f64; 2], scale: f64) -> [f32; 4] {
+    let (lx, ly, lw, lh) = layer_rect_at(ctx, offset, scale);
+    let (x0, y0) = (lx + 0.5, ly + 0.5);
+    [x0 as f32, y0 as f32, (lx + lw - 0.5).max(x0) as f32, (ly + lh - 0.5).max(y0) as f32]
+}
+
 pub(super) fn bubbles(ctx: &EffectCtx, mut b: Buf) -> Buf {
    let pr = ctx.params;
    let metal = pr.e("reflectionType") == 1;
    let shading = pr.e("shadingType");
    let list = bubble_list(ctx, &b);
+    let [x0, y0, x1, y1] = bubble_sample_bounds(ctx, b.offset, b.scale);
    let src = b.img.clone();
    let mut out = Image::new(src.width, src.height);
    raster(
@@ -182,7 +193,8 @@ pub(super) fn bubbles(ctx: &EffectCtx, mut b: Buf) -> Buf {
            // Liquid refracts (inverted, magnified), metal reflects (wide-angle mirror).
            let k = if metal { 1.6 } else { -0.7 };
            let nz = (1.0 - d2).max(0.0).sqrt();
-            let p = src.sample_bilinear((q.sx + dx * q.r * k) as f64, (q.sy + dy * q.r * k) as f64);
+            let (sx, sy) = ((q.sx + dx * q.r * k).max(x0).min(x1), (q.sy + dy * q.r * k).max(y0).min(y1));
+            let p = src.sample_bilinear_clamped(sx as f64, sy as f64);
            let (c, sa) = unpremul(p);
            let mut c = if sa <= 0.0 { [0.6, 0.7, 0.8] } else { c };
            let mut a = cov;
@@ -351,7 +351,7 @@ fn hex_cell(x: f64, y: f64, r: f64) -> ((f64, f64), (i64, i64)) {
    let rr = (2.0 / 3.0 * y) / r;
    // Cube rounding.
    let (cx, cz) = (q, rr);
-    let cy = -cx - cz;
+    let cy = (-3f64.sqrt() / 3.0 * x - y / 3.0) / r;
    let (mut rx, ry, mut rz) = (cx.round(), cy.round(), cz.round());
    let (dx, dy, dz) = ((rx - cx).abs(), (ry - cy).abs(), (rz - cz).abs());
    if dx > dy && dx > dz {
@@ -6,6 +6,10 @@ use effectcraft_color::{luminance, rgb_to_hsl};
 use effectcraft_raster::{Image, Px};
 use rayon::prelude::*;

+/// Below this many pixels, `Plane::transpose` and `Plane::map_rows` run on the calling thread:
+/// the rayon dispatch costs more than the work on small crops (the Match Grain sample boxes).
+const PAR_MIN: usize = 4096;
+
 /// A single-channel `f32` image (row-major).
 #[derive(Clone, Debug, Default, PartialEq)]
 pub struct Plane {
@@ -62,6 +66,15 @@ impl Plane {
    pub fn transpose(&self) -> Plane {
        let (w, h) = (self.w, self.h);
        let mut out = Plane::new(h, w);
+        if w.saturating_mul(h) < PAR_MIN {
+            // Small planes: the rayon dispatch costs more than the copy itself.
+            for (x, col) in out.data.chunks_mut(h.max(1)).enumerate() {
+                for y in 0..h {
+                    col[y] = self.data[y * w + x];
+                }
+            }
+            return out;
+        }
        out.data.par_chunks_mut(h.max(1)).enumerate().for_each(|(x, col)| {
            for y in 0..h {
                col[y] = self.data[y * w + x];
@@ -75,6 +88,11 @@ impl Plane {
        if self.w == 0 {
            return out;
        }
+        if self.w.saturating_mul(self.h) < PAR_MIN {
+            // Small planes: the rayon dispatch costs more than the rows themselves.
+            out.data.chunks_mut(self.w).zip(self.data.chunks(self.w)).for_each(|(o, s)| f(s, o));
+            return out;
+        }
        out.data.par_chunks_mut(self.w).zip(self.data.par_chunks(self.w)).for_each(|(o, s)| f(s, o));
        out
    }
@@ -534,14 +552,29 @@ impl<S: Clone> SimCache<S> {

    /// State after `target` steps. `init` builds step 0; `step(state, i)` advances from step
    /// `i` to `i + 1`.
-    pub fn run(&self, key: u64, target: u64, init: impl FnOnce() -> S, mut step: impl FnMut(&mut S, u64)) -> std::sync::Arc<S> {
+    pub fn run(&self, key: u64, target: u64, init: impl FnOnce() -> S, step: impl FnMut(&mut S, u64)) -> std::sync::Arc<S> {
+        self.run_where(key, target, init, step, |_, _| true)
+    }
+
+    /// [`SimCache::run`] for a simulation whose steps also depend on inputs outside `key` (a
+    /// parameter's values over time): a checkpoint after `s` steps is only resumed from when
+    /// `valid(s, state)` says it was reached with the same inputs. Fresh checkpoints replace
+    /// those at the same step.
+    pub fn run_where(
+        &self,
+        key: u64,
+        target: u64,
+        init: impl FnOnce() -> S,
+        mut step: impl FnMut(&mut S, u64),
+        valid: impl Fn(u64, &S) -> bool,
+    ) -> std::sync::Arc<S> {
        use std::sync::Arc;
        let start = {
            let mut g = self.inner.lock().unwrap_or_else(std::sync::PoisonError::into_inner);
            let tick = g.iter().map(|e| e.used).max().unwrap_or(0) + 1;
            g.iter_mut().find(|e| e.key == key).and_then(|e| {
                e.used = tick;
-                e.checkpoints.iter().filter(|(s, _)| *s <= target).max_by_key(|(s, _)| *s).map(|(s, st)| (*s, st.clone()))
+                e.checkpoints.iter().filter(|(s, st)| *s <= target && valid(*s, st)).max_by_key(|(s, _)| *s).map(|(s, st)| (*s, st.clone()))
            })
        };
        let had_start = start.is_some();
@@ -579,9 +612,8 @@ impl<S: Clone> SimCache<S> {
        let e = &mut g[idx];
        e.used = tick;
        for (s, st) in fresh {
-            if !e.checkpoints.iter().any(|(c, _)| *c == s) {
-                e.checkpoints.push((s, st));
-            }
+            e.checkpoints.retain(|(c, _)| *c != s);
+            e.checkpoints.push((s, st));
        }
        // Keep memory bounded: drop unaligned (exact-target) checkpoints first, then thin.
        if e.checkpoints.len() > 256 {
@@ -100,17 +100,11 @@ impl Cineon {
    fn knee(&self) -> f32 {
        1.0 - (self.rolloff / 100.0).clamp(0.0, 0.99)
    }
-    /// Normalised code value (code / 1023) → linear.
+    /// Normalized code value (code / 1023) → linear, raised to `1.7 / gamma`
+    /// ([`effectcraft_project::cineon_log_to_lin`], which Interpret Footage ▸ Cineon Settings
+    /// also uses with `1 / gamma`).
    pub fn log_to_lin(&self, v: f32) -> f32 {
-        let off = self.offset();
-        let code = v * 1023.0;
-        let mut lin = (10f32.powf((code - self.white) * 0.002 / 0.6) - off) / (1.0 - off).max(1e-6);
-        lin = lin.max(0.0).powf(1.7 / self.gamma.max(0.01));
-        let k = self.knee();
-        if k < 1.0 && lin > k {
-            let w = 1.0 - k;
-            lin = k + w * (1.0 - (-(lin - k) / w).exp());
-        }
+        let lin = effectcraft_project::cineon_log_to_lin(v, self.black, self.white, 1.7, self.gamma, self.rolloff);
        self.ib + (self.iw - self.ib) * lin
    }
    /// Linear → normalised code value.
@@ -495,6 +489,87 @@ mod tests {
        assert!(c.log_to_lin(95.0 / 1023.0).abs() < 1e-4);
    }

+    /// Interpret Footage ▸ Cineon Settings and the Cineon Converter's Log to Linear give the same
+    /// values for the same points and Highlight Rolloff when the converter's Gamma is 1.7 times
+    /// Cineon Settings' Gamma: the converter's default 1.7 and Cineon Settings' Gamma 1 both give
+    /// linear light (code 400 is 0.10251).
+    #[test]
+    fn cineon_converter_matches_interpret_footage() {
+        let codes = [0.0f32, 95.0, 250.0, 400.0, 560.0, 685.0, 800.0, 1023.0];
+        for (gamma, rolloff) in [(1.0, 20.0), (1.0, 0.0), (1.7, 50.0), (2.4, 50.0)] {
+            let mut img = Image::new(codes.len() as u32, 1);
+            for (x, code) in codes.iter().enumerate() {
+                let v = code / 1023.0;
+                img.set(x as u32, 0, [v, v, v, 1.0]);
+            }
+            let vals = [("conversionType", Value::Enum(1)), ("gamma", num(gamma * 1.7)), ("highlightRolloff", num(rolloff))];
+            let out = run("ec.utility.cineon", &vals, img);
+            let settings = effectcraft_project::CineonSettings { log_conversion: true, gamma: gamma as f32, rolloff: rolloff as f32, ..Default::default() };
+            for (x, code) in codes.iter().enumerate() {
+                let footage = settings.convert(code / 1023.0);
+                let effect = out.img.data[x][0];
+                assert!((footage - effect).abs() < 1e-6, "gamma {gamma}, rolloff {rolloff}, code {code}: {footage} vs {effect}");
+            }
+        }
+        let linear = effectcraft_project::CineonSettings { gamma: 1.0, rolloff: 0.0, ..Default::default() };
+        assert!((linear.convert(400.0 / 1023.0) - 0.10251).abs() < 1e-4);
+    }
+
+    /// The Cineon Converter gives the same values as before Cineon Settings shared its
+    /// log-to-linear function, at the default Gamma (1.7) and at Gamma 2.4, for all three
+    /// conversion types.
+    #[test]
+    fn cineon_converter_output_is_unchanged() {
+        fn log_to_lin(v: f32, gamma: f32, rolloff: f32, black: f32, white: f32) -> f32 {
+            let off = 10f32.powf((black - white) * 0.002 / 0.6);
+            let mut lin = (10f32.powf((v * 1023.0 - white) * 0.002 / 0.6) - off) / (1.0 - off).max(1e-6);
+            lin = lin.max(0.0).powf(1.7 / gamma.max(0.01));
+            let k = 1.0 - (rolloff / 100.0).clamp(0.0, 0.99);
+            if k < 1.0 && lin > k {
+                let w = 1.0 - k;
+                lin = k + w * (1.0 - (-(lin - k) / w).exp());
+            }
+            lin
+        }
+        fn lin_to_log(v: f32, gamma: f32, rolloff: f32, black: f32, white: f32) -> f32 {
+            let off = 10f32.powf((black - white) * 0.002 / 0.6);
+            let mut lin = v;
+            let k = 1.0 - (rolloff / 100.0).clamp(0.0, 0.99);
+            if k < 1.0 && lin > k {
+                let w = 1.0 - k;
+                lin = k - w * (1.0 - (lin - k) / w).max(1e-6).ln();
+            }
+            lin = lin.max(0.0).powf(gamma.max(0.01) / 1.7);
+            (white + (lin * (1.0 - off) + off).max(1e-9).log10() * 0.6 / 0.002) / 1023.0
+        }
+        let codes = [0.0f32, 95.0, 250.0, 400.0, 560.0, 685.0, 800.0, 1023.0];
+        for gamma in [None, Some(2.4)] {
+            for kind in 0..3 {
+                let mut img = Image::new(codes.len() as u32, 1);
+                for (x, code) in codes.iter().enumerate() {
+                    let v = code / 1023.0;
+                    img.set(x as u32, 0, [v, v, v, 1.0]);
+                }
+                let mut vals = vec![("conversionType", Value::Enum(kind))];
+                if let Some(g) = gamma {
+                    vals.push(("gamma", num(g)));
+                }
+                let out = run("ec.utility.cineon", &vals, img);
+                let g = gamma.unwrap_or(1.7) as f32;
+                for (x, code) in codes.iter().enumerate() {
+                    let v = code / 1023.0;
+                    let want = match kind {
+                        0 => lin_to_log(v, g, 20.0, 95.0, 685.0),
+                        1 => log_to_lin(v, g, 20.0, 95.0, 685.0),
+                        _ => lin_to_log(log_to_lin(v, g, 20.0, 95.0, 685.0), 1.7, 20.0, 95.0, 685.0),
+                    };
+                    let got = out.img.data[x][0];
+                    assert!((want - got).abs() < 1e-6, "gamma {g}, type {kind}, code {code}: {want} vs {got}");
+                }
+            }
+        }
+    }
+
    #[test]
    fn hdr_compression_behaviour() {
        let mut img = Image::new(2, 1);
@@ -152,15 +152,6 @@ pub fn settings(params: &Params, fps: f64) -> StabSettings {
    }
 }

-fn fnv(bytes: &[u8]) -> u64 {
-    let mut h: u64 = 0xcbf2_9ce4_8422_2325;
-    for b in bytes {
-        h ^= *b as u64;
-        h = h.wrapping_mul(0x0100_0000_01b3);
-    }
-    h
-}
-
 struct KeyHasher(u64);
 impl Hasher for KeyHasher {
    fn finish(&self) -> u64 {
@@ -183,24 +174,12 @@ fn settings_key(s: &StabSettings) -> u64 {
    h.finish()
 }

-type AnalysisCache = Mutex<HashMap<u64, Arc<WarpAnalysis>>>;
 type PlanCache = Mutex<HashMap<(u64, u64), Arc<Plan>>>;

-/// Parsed analyses by content hash (parsing a long clip's JSON every frame would dominate).
+/// Parsed analyses and their content keys; cache hits compare source text without rehashing.
 fn analysis_cached(json: &str) -> Option<(u64, Arc<WarpAnalysis>)> {
-    static C: OnceLock<AnalysisCache> = OnceLock::new();
-    let key = fnv(json.as_bytes());
-    let c = C.get_or_init(Default::default);
-    if let Some(a) = c.lock().unwrap_or_else(std::sync::PoisonError::into_inner).get(&key) {
-        return Some((key, a.clone()));
-    }
-    let a = Arc::new(WarpAnalysis::from_json(json)?);
-    let mut m = c.lock().unwrap_or_else(std::sync::PoisonError::into_inner);
-    if m.len() > 8 {
-        m.clear();
-    }
-    m.insert(key, a.clone());
-    Some((key, a))
+    static C: crate::analysis_cache::AnalysisCache<WarpAnalysis> = crate::analysis_cache::AnalysisCache::new();
+    C.get(json, WarpAnalysis::from_json)
 }

 fn plans() -> &'static PlanCache {
@@ -223,6 +202,19 @@ fn plan_cached(akey: u64, a: &WarpAnalysis, s: &StabSettings) -> Arc<Plan> {
    p
 }

+/// Validate and cache the default stabilization plan after analysis. Use the serialized
+/// analysis so the cached plan has exactly the same inputs as the first render, including
+/// any floating-point round trip through JSON. Other settings still get their own plan.
+pub fn prepare_default_plan(json: &str) -> bool {
+    let Some((key, a)) = analysis_cached(json) else { return false };
+    if a.is_empty() {
+        return false;
+    }
+    let fps = if a.frame_duration > 0.0 { 1.0 / a.frame_duration } else { 30.0 };
+    let p = plan_cached(key, &a, &StabSettings { fps, ..Default::default() });
+    p.warps.len() == a.frames.len() && p.warps.iter().all(|h| h.0.iter().flatten().all(|v| v.is_finite()))
+}
+
 /// The stored analysis of an instance (`None` when not analysed).
 pub fn analysis(params: &Params) -> Option<Arc<WarpAnalysis>> {
    let j = s(params, ANALYSIS);
@@ -531,6 +523,7 @@ fn dot(img: &mut Image, c: [f64; 2], r: f64, col: Px) {
 mod tests {
    use super::*;
    use crate::EffectEnv;
+    use crate::analysis_cache::fnv;
    use effectcraft_track::stabilize::FrameMotion;

    fn analysis_json(n: usize, w: f64, h: f64, shift: impl Fn(usize) -> [f64; 2]) -> String {
@@ -601,6 +594,61 @@ mod tests {
        assert_eq!(render(&ctx, Buf { img: img.clone(), offset: [0.0; 2], scale: 1.0 }).img.data, img.data);
    }

+    #[test]
+    fn prepared_default_plan_preserves_first_render_and_is_reused() {
+        let json = analysis_json(25, 64.0, 48.0, |k| [((k * 7) % 5) as f64 - 2.0, k as f64 * 0.1]);
+        let mut a = WarpAnalysis::from_json(&json).unwrap();
+        a.start = 0.012345678901234567;
+        a.tracks = (0..24)
+            .map(|id| effectcraft_track::camtrack::Track2D {
+                id,
+                start: 0,
+                pts: (0..25).map(|k| [8.0 + (id % 6) as f32 * 8.0 + ((k * 7) % 5) as f32, 8.0 + (id / 6) as f32 * 8.0 + k as f32 * 0.1]).collect(),
+            })
+            .collect();
+        let json = a.to_json();
+        let ps = params(&json, 2, 0);
+        let ctx = EffectCtx { params: &ps, time: a.start, layer_size: a.size, seed: 1, adjustment: false, env: EffectEnv::default() };
+        let input = Buf { img: frame([30.0, 22.0]), offset: [0.0; 2], scale: 1.0 };
+        // Original flow: validate, discard the plan, then render from the stored analysis.
+        let _discarded = plan(&a, &StabSettings { fps: 25.0, ..Default::default() });
+        let before = render(&ctx, input.clone());
+        let key = (fnv(json.as_bytes()), settings_key(&settings(&ps, 25.0)));
+        plans().lock().unwrap().remove(&key);
+        assert!(prepare_default_plan(&json));
+        let prepared = plans().lock().unwrap().get(&key).unwrap().clone();
+        assert!(!prepared.meshes.is_empty(), "exercise the Subspace Warp plan");
+        let after = render(&ctx, input);
+        let (_, _, rendered) = plan_at(&ps, a.start).unwrap();
+        assert!(Arc::ptr_eq(&prepared, &rendered));
+        assert_eq!(before.offset, after.offset);
+        assert_eq!(before.scale.to_bits(), after.scale.to_bits());
+        for (a, b) in before.img.data.iter().flatten().zip(after.img.data.iter().flatten()) {
+            assert_eq!(a.to_bits(), b.to_bits());
+        }
+        assert!(!prepare_default_plan("invalid"));
+        assert!(!prepare_default_plan(&WarpAnalysis::default().to_json()));
+    }
+
+    #[test]
+    fn changing_analysis_changes_the_plan_key() {
+        let json = analysis_json(10, 64.0, 48.0, |k| [k as f64 * 0.1, 0.0]);
+        let mut ps = params(&json, 2, 0);
+        let before = summary_key(&ps).unwrap();
+        assert_eq!(before[0], fnv(json.as_bytes()));
+        let mut a = WarpAnalysis::from_json(&json).unwrap();
+        a.start = 1.0;
+        ps.values.insert(ANALYSIS.into(), Value::Str(a.to_json()));
+        let after = summary_key(&ps).unwrap();
+        assert_ne!(before[0], after[0]);
+        assert_eq!(before[1], after[1]);
+        assert_eq!(*analysis(&ps).unwrap(), a);
+        ps.values.insert(ANALYSIS.into(), Value::Str(json));
+        assert_eq!(summary_key(&ps).unwrap(), before);
+        ps.values.insert(ANALYSIS.into(), Value::Str(String::new()));
+        assert!(analysis(&ps).is_none());
+    }
+
    #[test]
    fn nested_param_lookup() {
        let mut p = Params::default();
@@ -433,26 +433,26 @@ const GOLDEN: &[(&str, u64)] = &[
    ("ec.sim.ccstarburst/1/32bpc/t1.5", 0x5c39f8b1bd0e9e43),
    ("ec.sim.ccstarburst/1/32bpc/t0.8", 0xdf20aa9dcf4b3e22),
    ("ec.sim.ccstarburst/1/32bpc/t2.2", 0x4fa441737bfcb64d),
-    ("ec.sim.ccbubbles/0/8bpc/t0.5", 0xdcd187e75eeb2fae),
-    ("ec.sim.ccbubbles/0/8bpc/t1.5", 0x835ca088747736ed),
-    ("ec.sim.ccbubbles/0/8bpc/t0.8", 0x5cbb1a6fbb77b41d),
-    ("ec.sim.ccbubbles/0/8bpc/t2.2", 0x3b168068f5bfa533),
-    ("ec.sim.ccbubbles/0/32bpc/t0.5", 0x524b84d14edd77e2),
-    ("ec.sim.ccbubbles/0/32bpc/t1.5", 0xfd7a17f0d40f2a27),
-    ("ec.sim.ccbubbles/0/32bpc/t0.8", 0x70dd2b2b4ff0f7ce),
-    ("ec.sim.ccbubbles/0/32bpc/t2.2", 0xae21dd5cc2c2c07c),
-    ("ec.sim.ccbubbles/0/8bpc/half/t0.5", 0x931b4ca707604220),
-    ("ec.sim.ccbubbles/0/8bpc/half/t1.5", 0x21c25d4555abebe9),
-    ("ec.sim.ccbubbles/0/8bpc/half/t0.8", 0x7e05972683359632),
-    ("ec.sim.ccbubbles/0/8bpc/half/t2.2", 0xadc4f7219dab4921),
-    ("ec.sim.ccbubbles/1/8bpc/t0.5", 0x89d27a2fe2011067),
-    ("ec.sim.ccbubbles/1/8bpc/t1.5", 0x2bbfee897bf5bf6e),
-    ("ec.sim.ccbubbles/1/8bpc/t0.8", 0x26cc704e7b06fffc),
-    ("ec.sim.ccbubbles/1/8bpc/t2.2", 0x959d331545d96479),
-    ("ec.sim.ccbubbles/1/32bpc/t0.5", 0xaf486cebfcbf4641),
-    ("ec.sim.ccbubbles/1/32bpc/t1.5", 0xe150e9fdb558036f),
-    ("ec.sim.ccbubbles/1/32bpc/t0.8", 0x6395f3967cb24284),
-    ("ec.sim.ccbubbles/1/32bpc/t2.2", 0x68a55894d86ffb9e),
+    ("ec.sim.ccbubbles/0/8bpc/t0.5", 0x6cb63df0c062fdf4),
+    ("ec.sim.ccbubbles/0/8bpc/t1.5", 0x5bb1350114234ac3),
+    ("ec.sim.ccbubbles/0/8bpc/t0.8", 0xaa824d49f12c4156),
+    ("ec.sim.ccbubbles/0/8bpc/t2.2", 0x3528577358c4fc90),
+    ("ec.sim.ccbubbles/0/32bpc/t0.5", 0xdcd8e71222c13a9a),
+    ("ec.sim.ccbubbles/0/32bpc/t1.5", 0xd09565e124d8f5db),
+    ("ec.sim.ccbubbles/0/32bpc/t0.8", 0x91242f8e1fd0ad84),
+    ("ec.sim.ccbubbles/0/32bpc/t2.2", 0x1f9782131e62149d),
+    ("ec.sim.ccbubbles/0/8bpc/half/t0.5", 0x020755e48bdf8f43),
+    ("ec.sim.ccbubbles/0/8bpc/half/t1.5", 0x4aac0f1332e6001e),
+    ("ec.sim.ccbubbles/0/8bpc/half/t0.8", 0xdc2ab5e04c4a95a2),
+    ("ec.sim.ccbubbles/0/8bpc/half/t2.2", 0x30f78adc5d1dd715),
+    ("ec.sim.ccbubbles/1/8bpc/t0.5", 0x2f5415c679ff0980),
+    ("ec.sim.ccbubbles/1/8bpc/t1.5", 0xfcfc354dcd22e6d0),
+    ("ec.sim.ccbubbles/1/8bpc/t0.8", 0xdf90fd57c217019c),
+    ("ec.sim.ccbubbles/1/8bpc/t2.2", 0xd365c88c12219802),
+    ("ec.sim.ccbubbles/1/32bpc/t0.5", 0x50f20497f40bb46d),
+    ("ec.sim.ccbubbles/1/32bpc/t1.5", 0x74760599ffba220a),
+    ("ec.sim.ccbubbles/1/32bpc/t0.8", 0x028de52900ed8618),
+    ("ec.sim.ccbubbles/1/32bpc/t2.2", 0xaf0e21d9a7f625fe),
    ("ec.sim.ccdrizzle/0/8bpc/t0.5", 0x2bdfbc17d92b65b5),
    ("ec.sim.ccdrizzle/0/8bpc/t1.5", 0x8c354c46f99e35d3),
    ("ec.sim.ccdrizzle/0/8bpc/t0.8", 0x891f331ba47ee557),
@@ -39,3 +39,7 @@ rayon = { workspace = true }
 image = { workspace = true }
 web-time = { workspace = true }
 exr = { workspace = true }
+
+# Native only: the volume's own identity for a file, to tell that a hard link is the footage it leads to.
+[target.'cfg(not(target_arch = "wasm32"))'.dependencies]
+same-file = { workspace = true }
@@ -0,0 +1,248 @@
+{
+  "format": "effectcraft.animationPresets/1",
+  "notes": "Original EffectCraft behavior presets (MIT OR Apache-2.0), written from scratch. Each one drives a transform property or opacity with a time-based expression built on the property's own value, so the motion runs for the layer's whole duration and still follows the property's keyframes. Apply to any layer; no effects are added.",
+  "presets": [
+    {
+      "id": "wiggleSoft",
+      "name": "Soft Wiggle",
+      "category": "Behaviors",
+      "description": "The layer wanders gently around its position.",
+      "layer": {
+        "expr": {
+          "transform/position": "var w = wiggle(1.2, 30); [w[0], w[1]]"
+        }
+      }
+    },
+    {
+      "id": "shake",
+      "name": "Shake",
+      "category": "Behaviors",
+      "description": "A fast, tight shake of the layer's position.",
+      "layer": {
+        "expr": {
+          "transform/position": "var w = wiggle(14, 12); [w[0], w[1]]"
+        }
+      }
+    },
+    {
+      "id": "floatUpDown",
+      "name": "Float",
+      "category": "Behaviors",
+      "description": "The layer bobs up and down like it floats on water.",
+      "layer": {
+        "expr": {
+          "transform/position": "[value[0]+(0), value[1]+(Math.sin(time*2)*18)]"
+        }
+      }
+    },
+    {
+      "id": "sway",
+      "name": "Sway",
+      "category": "Behaviors",
+      "description": "The layer sways left and right.",
+      "layer": {
+        "expr": {
+          "transform/position": "[value[0]+(Math.sin(time*1.6)*40), value[1]+(0)]"
+        }
+      }
+    },
+    {
+      "id": "orbit",
+      "name": "Orbit",
+      "category": "Behaviors",
+      "description": "The layer travels round a circle around its position.",
+      "layer": {
+        "expr": {
+          "transform/position": "[value[0]+(Math.cos(time*2)*80), value[1]+(Math.sin(time*2)*80)]"
+        }
+      }
+    },
+    {
+      "id": "figureEight",
+      "name": "Figure Eight",
+      "category": "Behaviors",
+      "description": "The layer traces a figure eight around its position.",
+      "layer": {
+        "expr": {
+          "transform/position": "[value[0]+(Math.sin(time*1.5)*100), value[1]+(Math.sin(time*3)*45)]"
+        }
+      }
+    },
+    {
+      "id": "bouncingBall",
+      "name": "Bouncing Ball",
+      "category": "Behaviors",
+      "description": "The layer bounces up from its position again and again.",
+      "layer": {
+        "expr": {
+          "transform/position": "[value[0]+(0), value[1]+(-Math.abs(Math.sin(time*3.2))*140)]"
+        }
+      }
+    },
+    {
+      "id": "driftRight",
+      "name": "Drift Right",
+      "category": "Behaviors",
+      "description": "The layer drifts steadily to the right.",
+      "layer": {
+        "expr": {
+          "transform/position": "[value[0]+(time*40), value[1]+(0)]"
+        }
+      }
+    },
+    {
+      "id": "driftDiagonal",
+      "name": "Drift Diagonal",
+      "category": "Behaviors",
+      "description": "The layer drifts slowly down and to the right.",
+      "layer": {
+        "expr": {
+          "transform/position": "[value[0]+(time*30), value[1]+(time*18)]"
+        }
+      }
+    },
+    {
+      "id": "pendulum",
+      "name": "Pendulum",
+      "category": "Behaviors",
+      "description": "The layer swings like a pendulum.",
+      "layer": {
+        "expr": {
+          "transform/rotation": "value + Math.sin(time*2.4)*25"
+        }
+      }
+    },
+    {
+      "id": "wobble",
+      "name": "Wobble",
+      "category": "Behaviors",
+      "description": "The layer rotates with an irregular wobble.",
+      "layer": {
+        "expr": {
+          "transform/rotation": "wiggle(2, 10)"
+        }
+      }
+    },
+    {
+      "id": "spinSlow",
+      "name": "Spin Slow",
+      "category": "Behaviors",
+      "description": "The layer rotates once every ten seconds.",
+      "layer": {
+        "expr": {
+          "transform/rotation": "value + time*36"
+        }
+      }
+    },
+    {
+      "id": "spinFast",
+      "name": "Spin Fast",
+      "category": "Behaviors",
+      "description": "The layer rotates twice a second.",
+      "layer": {
+        "expr": {
+          "transform/rotation": "value + time*720"
+        }
+      }
+    },
+    {
+      "id": "pulse",
+      "name": "Pulse",
+      "category": "Behaviors",
+      "description": "The layer swells and shrinks smoothly.",
+      "layer": {
+        "expr": {
+          "transform/scale": "[value[0]*(1+0.12*Math.sin(time*4)), value[1]*(1+0.12*Math.sin(time*4))]"
+        }
+      }
+    },
+    {
+      "id": "heartbeat",
+      "name": "Heartbeat",
+      "category": "Behaviors",
+      "description": "Two quick beats, then a rest, repeating every second.",
+      "layer": {
+        "expr": {
+          "transform/scale": "var t = time % 1; var b = t < 0.3 ? Math.sin(t/0.3*Math.PI) : (t < 0.6 ? 0.7*Math.sin((t-0.3)/0.3*Math.PI) : 0); var k = 1 + 0.2*b; [value[0]*k, value[1]*k]"
+        }
+      }
+    },
+    {
+      "id": "breathe",
+      "name": "Breathe",
+      "category": "Behaviors",
+      "description": "The layer slowly grows and settles back.",
+      "layer": {
+        "expr": {
+          "transform/scale": "[value[0]*(1+0.06*Math.sin(time*1.1)), value[1]*(1+0.06*Math.sin(time*1.1))]"
+        }
+      }
+    },
+    {
+      "id": "rubberBand",
+      "name": "Rubber Band",
+      "category": "Behaviors",
+      "description": "Width and height stretch against each other.",
+      "layer": {
+        "expr": {
+          "transform/scale": "[value[0]*(1+0.15*Math.sin(time*5)), value[1]*(1-0.15*Math.sin(time*5))]"
+        }
+      }
+    },
+    {
+      "id": "jitterScale",
+      "name": "Jitter Scale",
+      "category": "Behaviors",
+      "description": "The layer's size jitters randomly.",
+      "layer": {
+        "expr": {
+          "transform/scale": "var w = wiggle(8, 6); [w[0], w[1]]"
+        }
+      }
+    },
+    {
+      "id": "blink",
+      "name": "Blink",
+      "category": "Behaviors",
+      "description": "The layer switches on and off twice a second.",
+      "layer": {
+        "expr": {
+          "transform/opacity": "(Math.floor(time*4) % 2 === 0) ? value : 0"
+        }
+      }
+    },
+    {
+      "id": "strobe",
+      "name": "Strobe",
+      "category": "Behaviors",
+      "description": "The layer flashes on for a few frames each beat.",
+      "layer": {
+        "expr": {
+          "transform/opacity": "((time*6) % 1 < 0.25) ? value : 0"
+        }
+      }
+    },
+    {
+      "id": "flicker",
+      "name": "Flicker",
+      "category": "Behaviors",
+      "description": "The layer's opacity flickers like a failing lamp.",
+      "layer": {
+        "expr": {
+          "transform/opacity": "var w = wiggle(14, 45); Math.max(0, Math.min(100, w))"
+        }
+      }
+    },
+    {
+      "id": "fadePulse",
+      "name": "Fade Pulse",
+      "category": "Behaviors",
+      "description": "Opacity breathes between full and a third.",
+      "layer": {
+        "expr": {
+          "transform/opacity": "value*(0.67+0.33*Math.sin(time*2.5))"
+        }
+      }
+    }
+  ]
+}
@@ -0,0 +1,7 @@
+asset:        behaviors.json
+title:        EffectCraft Behaviors animation presets (Soft Wiggle, Shake, Float, Sway, Orbit, Figure Eight, Bouncing Ball, Drift Right, Drift Diagonal, Pendulum, Wobble, Spin Slow, Spin Fast, Pulse, Heartbeat, Breathe, Rubber Band, Jitter Scale, Blink, Strobe, Flicker, Fade Pulse)
+author:       EffectCraft contributors
+source:       original work
+license:      MIT OR Apache-2.0
+added:        2026-10-15 by vangel76 (Claude Code agent, gap 7, #1510)
+notes:        Expressions and values written from scratch for EffectCraft on its own transform properties and expression engine; not derived from any Adobe preset (.ffx) or its values.
@@ -77,7 +77,7 @@
          "name": "Tracking In",
          "properties": { "tracking": 0, "opacity": 100 },
          "keys": {
-            "tracking": [[0, 400], [1.6, 0]],
+            "tracking": [[0, 40], [1.6, 0]],
            "opacity": [[0, 0], [0.8, 100]]
          },
          "ease": true,
@@ -197,7 +197,8 @@ pub(crate) struct Work {
 }

 /// The layer's source frame at comp time `t` at 100 % (layer pixels + offset = image pixels).
-/// Footage at its native size is used straight from the footage source (no copy).
+/// Footage at its native size is used straight from the footage source (no copy unless its
+/// Cineon Settings convert it).
 pub(crate) fn source_frame(
    r: &Renderer,
    project: &Project,
@@ -207,7 +208,7 @@ pub(crate) fn source_frame(
    t: Tick,
    expr: Option<&dyn ExprHost>,
 ) -> Option<(Arc<Image>, [f64; 2])> {
-    let ctx = EvalCtx { project, comp_id: cid, comp, time: t, expr, footage: None };
+    let ctx = EvalCtx { project, comp_id: cid, comp, time: t, expr, footage: None, property_overrides: &[], media_overrides: &[] };
    if let effectcraft_project::LayerSource::Footage { item } = &layer.source
        && let Some(effectcraft_project::ItemKind::Footage(f)) = project.item(*item).map(|i| &i.kind)
        && f.has_video
@@ -215,7 +216,7 @@ pub(crate) fn source_frame(
        && img.width == f.width
        && img.height == f.height
    {
-        return Some((img, [0.0; 2]));
+        return Some((effectcraft_render::cineon_frame(img, f), [0.0; 2]));
    }
    let buf = r.layer_source(&ctx, layer)?;
    if (buf.scale - 1.0).abs() > 1e-9 && buf.scale > 0.0 {
@@ -4,7 +4,7 @@
 //! the Warp Stabilizer, `Renderer::layer_input`) for every frame between the layer's In and Out
 //! points on a background thread, and feeds the frames to `effectcraft_track::stabilize`'s
 //! analyzer (step 1 of 2, "Analyzing in background"); step 2 ("Stabilizing") derives the
-//! stabilization plan once to validate the result. When the job finishes, the analysis is
+//! stabilization plan once to validate and cache the result. When the job finishes, the analysis is
 //! written into the effect's hidden Analysis parameter as one undo step, together with a key of
 //! what it was made from (the layer's source, In/Out, start, stretch and Time Remap). Edits that
 //! change those clear the analysis (`invalidate`, run after every edit) and queue the effect
@@ -21,7 +21,7 @@ use effectcraft_project::{GroupKind, ItemId, ItemKind, Layer, LayerId, LayerSour
 use effectcraft_raster::Image;
 use effectcraft_render::{EvalCtx, ExprHost, FootageSource, LayerCache, Renderer};
 use effectcraft_time::Tick;
-use effectcraft_track::stabilize::{AnalyzeOpts, Analyzer, StabSettings, WarpAnalysis};
+use effectcraft_track::stabilize::{AnalyzeOpts, Analyzer, WarpAnalysis};
 use serde::Serialize;

 use crate::tracking::lock;
@@ -245,9 +245,8 @@ async fn run_work(w: WarpWork, shared: &WarpShared) {
    let lt0 = layer.layer_time(w.times[0]).seconds();
    let fd = if w.times.len() > 1 { layer.layer_time(w.times[1]).seconds() - lt0 } else { comp.frame_duration().seconds() };
    let a = an.finish(lt0, fd);
-    // Step 2: derive a plan once (validates the motion and warms nothing else up).
-    let plan = effectcraft_track::stabilize::plan(&a, &StabSettings { fps: if fd > 0.0 { 1.0 / fd } else { 30.0 }, ..Default::default() });
-    if plan.warps.len() != a.frames.len() || plan.warps.iter().any(|h| h.0.iter().flatten().any(|v| !v.is_finite())) {
+    // Plan from the stored JSON, exactly as rendering does, and retain it for the first render.
+    if !warp_stab::prepare_default_plan(&a.to_json()) {
        return fail("the stabilization could not be computed");
    }
    *lock(&shared.result) = Some(a);
@@ -10,6 +10,7 @@ mod animation;
 pub(crate) mod app_more;
 mod autotrace;
 mod batch;
+mod blender;
 mod camera_cmds;
 mod comp;
 pub(crate) mod comp_more;
@@ -163,8 +164,8 @@ pub use enabled::always;
 pub(crate) use enabled::{has_comp, has_keys, has_layers, has_project_selection, not_yet, not_yet_run};
 pub use params::match_path_of;
 pub(crate) use params::{
-    b_p, bad, comp_id, f_p, frontend, layer_mut, layer_p, layers_or, layers_p, merge_p, resolve_effect_path, resolve_layer, selectable, selected_leaf_props,
-    str_p, time_p, unlocked, visible_p,
+    b_p, bad, comp_id, f_p, frontend, layer_mut, layer_p, layers_or, layers_p, merge_p, popup_options, resolve_effect_path, resolve_layer, selectable,
+    selected_leaf_props, str_p, time_p, unlocked, visible_p,
 };
 pub use schema::{accepted_params, check_params, params_schema};

@@ -45,6 +45,7 @@ fn copy(s: &mut Session, _: &Value) -> Result<Value> {
        clip.push(KeyClip { layer: lid, path, keys });
    }
    let n: usize = clip.iter().map(|c| c.keys.len()).sum();
+    s.state.keyframe_text = crate::keyframe_text::text(&s.project, comp, &s.state.selected_keys, &[]);
    s.state.key_clipboard = clip;
    s.state.clip_is_keys = true;
    Ok(json!(n))
@@ -1,6 +1,7 @@
 //! EffectCraft's own animation preset library (Effects & Presets ▸ * Animation Presets): the
 //! Transitions category (original presets built on our Transition effects and layer opacity) and
-//! the Backgrounds category (generators, noise and colour effects driven by expressions).
+//! the Backgrounds category (generators, noise and colour effects driven by expressions) and the
+//! Behaviors category (transform and opacity driven by expressions, no effects).
 //!
 //! Each preset adds effects (with values and keyframes) and/or keys layer properties, starting
 //! at the current time, on every selected layer. The library is data
@@ -26,13 +27,17 @@ pub const TRANSITIONS_JSON: &str = include_str!("../../presets/transitions.json"
 /// The original background presets (`presets/backgrounds.json`).
 pub const BACKGROUNDS_JSON: &str = include_str!("../../presets/backgrounds.json");

+/// The original behavior presets (`presets/behaviors.json`): expression-driven motion on a layer's
+/// transform and opacity, no effects.
+pub const BEHAVIORS_JSON: &str = include_str!("../../presets/behaviors.json");
+
 /// Keys per animated property, so a hostile inline preset can't allocate without bound.
 const MAX_KEYS: usize = 256;
 /// Longest expression text an inline preset may carry.
 const MAX_EXPR: usize = 4096;

 fn presets() -> Vec<Value> {
-    [TRANSITIONS_JSON, BACKGROUNDS_JSON]
+    [TRANSITIONS_JSON, BACKGROUNDS_JSON, BEHAVIORS_JSON]
        .iter()
        .flat_map(|src| serde_json::from_str::<Value>(src).ok().and_then(|v| v.get("presets").and_then(Value::as_array).cloned()).unwrap_or_default())
        .collect()
@@ -10,11 +10,16 @@ use effectcraft_project::{GroupKind, Layer, LayerId, LayerSource, Node, Project,
 use effectcraft_time::Tick;
 use serde_json::{Value, json};

+use super::effect::{effect_time_error, retime_effect};
 use super::{CommandSpec, bad, frontend, has_comp, has_keys, has_layers, layer_mut, layers_p, match_path_of, resolve_effect_path, selected_leaf_props, str_p};
 use crate::{EngineError, KeyRef, Result, Session, cmd};

 /// Preset file format version tag (`*.ecpreset`, JSON).
 pub const PRESET_TAG: &str = "effectcraftAnimationPreset";
+/// The preset format version that `anim.savePreset` writes.
+pub const PRESET_VERSION: u64 = 2;
+/// The first preset version that stores effect keys relative to the earliest key (#1971).
+const RELATIVE_EFFECT_KEYS: u64 = 2;

 fn has_selected_props(s: &Session) -> std::result::Result<(), String> {
    has_comp(s)?;
@@ -45,13 +50,26 @@ fn selected_effects(s: &Session) -> Vec<(LayerId, PropGroup)> {
        .collect()
 }

+/// The earliest key anywhere in `groups`, nested controls included.
+fn earliest_key<'a>(groups: impl IntoIterator<Item = &'a PropGroup>) -> Option<Tick> {
+    let mut first: Option<Tick> = None;
+    for g in groups {
+        g.walk("", &mut |_, pr| {
+            if let Some(t) = pr.keys.iter().map(|k| k.time).min() {
+                first = Some(first.map_or(t, |f| f.min(t)));
+            }
+        });
+    }
+    first
+}
+
 // ---------------------------------------------------------------- presets

 fn save_preset(s: &mut Session, p: &Value) -> Result<Value> {
    let path = str_p(p, "path").ok_or_else(|| bad("anim.savePreset", "missing `path`"))?.to_string();
    let comp = s.active_comp().ok_or(EngineError::NoComp)?;
    let t = s.time();
-    let effects: Vec<(LayerId, PropGroup)> = selected_effects(s);
+    let mut effects: Vec<(LayerId, PropGroup)> = selected_effects(s);
    let effect_uids: Vec<Uid> = effects.iter().map(|(_, g)| g.uid).collect();
    let mut props = vec![];
    for (lid, uid) in selected_leaf_props(s) {
@@ -67,7 +85,11 @@ fn save_preset(s: &mut Session, p: &Value) -> Result<Value> {
        return Err(bad("anim.savePreset", "select properties or effects to save"));
    }
    // Key times are stored relative to the earliest key so the preset applies at the CTI.
-    let first = props.iter().flat_map(|(_, _, pr)| pr.keys.iter().map(|k| k.time)).min().unwrap_or(Tick::ZERO);
+    let first =
+        props.iter().flat_map(|(_, _, pr)| pr.keys.iter().map(|k| k.time)).chain(earliest_key(effects.iter().map(|(_, g)| g))).min().unwrap_or(Tick::ZERO);
+    for (_, g) in &mut effects {
+        retime_effect(g, 1.0, "anim.savePreset", |t| Ok(Tick(t.0.checked_sub(first.0).ok_or_else(|| effect_time_error("anim.savePreset"))?)))?;
+    }
    let props_json: Vec<Value> = props
        .iter()
        .map(|(_, mp, pr)| {
@@ -82,12 +104,27 @@ fn save_preset(s: &mut Session, p: &Value) -> Result<Value> {
    let name = str_p(p, "name")
        .map(str::to_string)
        .unwrap_or_else(|| std::path::Path::new(&path).file_stem().map(|s| s.to_string_lossy().to_string()).unwrap_or_default());
-    let doc = json!({PRESET_TAG: 1, "name": name, "properties": props_json, "effects": fx_json});
+    let doc = json!({PRESET_TAG: PRESET_VERSION, "name": name, "properties": props_json, "effects": fx_json});
    let text = serde_json::to_string_pretty(&doc).unwrap_or_default();
    s.services.write_file(&path, text.as_bytes()).map_err(|e| EngineError::Other(format!("cannot write {path}: {e}")))?;
    Ok(json!({"path": path, "properties": props.len(), "effects": effects.len()}))
 }

+/// Rewrite an effect property path in a preset (`effects/<effect id>[#n]/<param>`) to the current
+/// parameter id when it names a parameter that the effect has since renamed or moved into a
+/// twirl-down group. Any other path comes back unchanged.
+fn upgrade_effect_path(path: &str) -> String {
+    let Some((seg, tail)) = path.strip_prefix("effects/").and_then(|r| r.split_once('/')) else { return path.to_string() };
+    let effect = match seg.rsplit_once('#') {
+        Some((m, n)) if !m.is_empty() && n.parse::<usize>().is_ok() => m,
+        _ => seg,
+    };
+    match effectcraft_effects::find(effect).and_then(|spec| effectcraft_effects::migrate::current_param_id(spec, tail)) {
+        Some(id) if id != tail => format!("effects/{seg}/{id}"),
+        _ => path.to_string(),
+    }
+}
+
 fn apply_preset(s: &mut Session, p: &Value) -> Result<Value> {
    let doc: Value = match (p.get("preset"), str_p(p, "path")) {
        (Some(v), _) => v.clone(),
@@ -110,14 +147,22 @@ fn apply_preset(s: &mut Session, p: &Value) -> Result<Value> {
        s.save_prefs();
        s.prefs_revision += 1;
    }
-    let effects: Vec<PropGroup> =
+    let mut effects: Vec<PropGroup> =
        doc["effects"].as_array().map(|a| a.iter().filter_map(|v| serde_json::from_value(v.clone()).ok()).collect()).unwrap_or_default();
+    // Older presets stored effect keys at the source layer's times.
+    if doc[PRESET_TAG].as_u64().unwrap_or(1) < RELATIVE_EFFECT_KEYS
+        && let Some(first) = earliest_key(&effects)
+    {
+        for g in &mut effects {
+            retime_effect(g, 1.0, "anim.applyPreset", |t| Ok(Tick(t.0.checked_sub(first.0).ok_or_else(|| effect_time_error("anim.applyPreset"))?)))?;
+        }
+    }
    let props: Vec<(String, Property)> = doc["properties"]
        .as_array()
        .map(|a| {
            a.iter()
                .filter_map(|v| {
-                    let path = v["path"].as_str()?.to_string();
+                    let path = upgrade_effect_path(v["path"].as_str()?);
                    let value: KV = serde_json::from_value(v["value"].clone()).ok()?;
                    let keys: Vec<Keyframe> = serde_json::from_value(v["keys"].clone()).unwrap_or_default();
                    let expr = serde_json::from_value(v["expression"].clone()).ok().flatten();
@@ -130,16 +175,30 @@ fn apply_preset(s: &mut Session, p: &Value) -> Result<Value> {
        })
        .unwrap_or_default();
    let t = s.time();
+    // Effect bounds per layer size the point defaults of parameters added since the preset was saved.
+    let comp = s.project.comp(cid).ok_or(EngineError::NoComp)?;
+    let sizes: BTreeMap<LayerId, [f64; 2]> =
+        ids.iter().filter_map(|lid| comp.layer(*lid).map(|l| (*lid, effectcraft_render::effect_bounds(&s.project, comp, l).0))).collect();
    let mut applied = 0;
    let mut skipped = vec![];
    s.edit("Apply Animation Preset", None, |proj, _| {
        let mut next = proj.next_id;
        for lid in &ids {
+            let size = sizes.get(lid).copied().unwrap_or([100.0, 100.0]);
            let l = layer_mut(proj, cid, *lid)?;
            let lt = l.layer_time(t);
            if let Some(fx) = l.props.sub_mut("effects") {
                for g in &effects {
                    let mut g = g.clone();
+                    // Effects saved by an earlier version get the upgrade a project gets on open.
+                    let spec = match &g.kind {
+                        GroupKind::Effect { effect } => effectcraft_effects::find(effect),
+                        _ => None,
+                    };
+                    if let Some(spec) = spec {
+                        effectcraft_effects::migrate::upgrade_instance(spec, &mut g, &mut Ids(&mut next), size);
+                    }
+                    retime_effect(&mut g, 1.0, "anim.applyPreset", |t| Ok(Tick(t.0.checked_add(lt.0).ok_or_else(|| effect_time_error("anim.applyPreset"))?)))?;
                    g.reassign_uids(&mut next);
                    next += 1;
                    fx.children.push(Node::Group(g));
@@ -184,7 +243,7 @@ fn add_keyframe(s: &mut Session, _: &Value) -> Result<Value> {
    }
    let cid = s.active_comp_id().ok_or(EngineError::NoComp)?;
    let t = s.time();
-    let n = s.edit("Add Keyframe", None, |proj, _| {
+    let n = s.edit("Add Keyframe", None, |proj, state| {
        let mut n = 0;
        for (lid, uid) in &targets {
            let l = layer_mut(proj, cid, *lid)?;
@@ -200,6 +259,9 @@ fn add_keyframe(s: &mut Session, _: &Value) -> Result<Value> {
                pr.set_value_at(lt, v);
            }
            n += 1;
+            if pr.match_id == "type" {
+                super::prop::sync_polystar_property(proj, state, cid, *lid, *uid, t)?;
+            }
        }
        Ok(n)
    })?;
@@ -152,7 +152,7 @@ fn clear_recent_presets(s: &mut Session, _: &Value) -> Result<Value> {

 fn save_copy_xml(s: &mut Session, p: &Value) -> Result<Value> {
    let path = str_p(p, "path").ok_or_else(|| bad("file.saveCopyAsXml", "missing `path` (.ecprojx)"))?;
-    let xml = crate::xml_project::to_xml(&s.project.to_file_json_with_view(&s.saved_view())?).map_err(EngineError::Other)?;
+    let xml = crate::xml_project::to_xml(&s.project.to_file_json_with_view(&s.saved_view(), false)?).map_err(EngineError::Other)?;
    s.services.write_file(path, xml.as_bytes()).map_err(|e| EngineError::Other(format!("cannot write {path}: {e}")))?;
    s.toast(format!("Saved an XML copy to {path}"));
    Ok(json!({"path": path, "bytes": xml.len()}))
@@ -240,7 +240,7 @@ fn replace_with_precomp(s: &mut Session, p: &Value) -> Result<Value> {
            let ids: Vec<ItemId> = proj.items.keys().copied().filter(|c| *c != comp).collect();
            for cid in ids {
                if let Some(c) = proj.comp_mut(cid) {
-                    for l in c.layers.iter_mut().filter(|l| is_user(l)) {
+                    for l in c.layers.iter_mut_where(|l| is_user(l)) {
                        l.source = LayerSource::Comp { item: comp };
                        n += 1;
                    }
@@ -9,8 +9,9 @@ use serde_json::{Value, json};
 use super::{CommandSpec, always, bad, str_p};
 use crate::{EngineError, Result, Session};

-/// Commands that can't run inside a batch (they replace the project or nest batches).
-const NOT_IN_BATCH: &[&str] = &["engine.batch", "file.runScript", "script.run"];
+/// Commands that can't run inside a batch (they nest batches), besides the commands that run
+/// scripts ([`super::scripts::RUNS_SCRIPTS`]).
+const NOT_IN_BATCH: &[&str] = &["engine.batch"];

 /// Resolve a `$N` / `$N.key.0.key` reference against the results so far.
 fn reference(s: &str, results: &[Value]) -> Option<Result<Value>> {
@@ -78,7 +79,7 @@ fn batch(s: &mut Session, p: &Value) -> Result<Value> {
                .or_else(|| step.get("id"))
                .and_then(Value::as_str)
                .ok_or_else(|| bad("engine.batch", "each step needs `command` (a command id)"))?;
-            if NOT_IN_BATCH.contains(&id) {
+            if NOT_IN_BATCH.contains(&id) || super::scripts::RUNS_SCRIPTS.contains(&id) {
                return Err(bad("engine.batch", format!("`{id}` can't run inside a batch")));
            }
            let params = substitute(step.get("params").unwrap_or(&json!({})), results)?;
@@ -0,0 +1,295 @@
+//! Camera-solve interchange through Blender's public Python API. The generated script is
+//! original MIT OR Apache-2.0 code; no Blender implementation is read or embedded.
+
+use std::path::Path;
+
+use effectcraft_effects::camera_tracker as ct;
+use effectcraft_project::{Footage, FootageKind, ItemId, ItemKind, Layer, LayerId, LayerSource, Uid};
+use effectcraft_render::EvalCtx;
+use effectcraft_time::Tick;
+use effectcraft_track::camtrack::{CameraSolve, linalg};
+use serde_json::{Value, json};
+
+mod validate;
+
+use super::{b_p, bad, f_p, str_p};
+use crate::{EngineError, Result, Session};
+
+const CMD: &str = "camera.exportBlender";
+const MAX_FRAMES: usize = 100_000;
+const MAX_POINTS: usize = 100_000;
+const MAX_JSON: usize = 64 * 1024 * 1024;
+const MAX_FRAME: i64 = 1_048_574;
+
+fn number(p: &Value, key: &str, default: f64, min: f64, max: f64) -> Result<f64> {
+    let v = match p.get(key) {
+        None => default,
+        Some(_) => f_p(p, key).ok_or_else(|| bad(CMD, format!("{key}: expected a number")))?,
+    };
+    if !v.is_finite() || !(min..=max).contains(&v) {
+        return Err(bad(CMD, format!("{key}: expected {min}..{max}")));
+    }
+    Ok(v)
+}
+
+fn finite(values: impl IntoIterator<Item = f64>) -> Result<()> {
+    if values.into_iter().any(|v| !v.is_finite() || v.abs() > 1e12) {
+        return Err(bad(CMD, "invalid or excessive numeric camera/scene data; re-analyze the tracker"));
+    }
+    Ok(())
+}
+
+/// Right-handed EffectCraft world (right, down, forward) → Blender (right, forward, up).
+fn position(p: [f64; 3], scale: f64) -> [f64; 3] {
+    [p[0] * scale, p[2] * scale, -p[1] * scale]
+}
+
+fn media_path(s: &Session, path: &str) -> Result<String> {
+    if path.is_empty() || path.contains('\0') {
+        return Err(bad(CMD, "the source footage has no valid file path; relink it before exporting"));
+    }
+    let path = Path::new(path);
+    if path.is_absolute() || cfg!(target_arch = "wasm32") {
+        return Ok(path.to_string_lossy().into_owned());
+    }
+    let cwd = std::env::current_dir().map_err(|e| bad(CMD, format!("cannot resolve footage path: {e}")))?;
+    let base = s.path.as_deref().and_then(|p| Path::new(p).parent()).map(|p| cwd.join(p)).unwrap_or(cwd);
+    Ok(base.join(path).to_string_lossy().into_owned())
+}
+
+pub(super) fn export(s: &mut Session, p: &Value, cid: ItemId, lid: LayerId, uid: Uid) -> Result<Value> {
+    if s.running_for_script() && !s.prefs.scripting.allow_scripts_write_files {
+        return Err(bad(CMD, "scripts can't export files unless Settings ▸ Scripting & Expressions ▸ Allow Scripts to Write Files and Access Network is on"));
+    }
+    let options = Options::parse(p)?;
+    let Options { path, sensor, units, start, include_points } = options;
+    if s.camera_target().is_some_and(|(c, l, u)| (c, l, u) == (cid, lid, uid)) && s.is_camera_analyzing() || s.camera_pending.contains(&(cid, lid, uid)) {
+        return Err(bad(CMD, "wait for this tracker's analysis to finish before exporting"));
+    }
+    let comp = s.project.comp(cid).ok_or(EngineError::NoComp)?;
+    let layer = comp.layer(lid).ok_or_else(|| bad(CMD, "tracked layer missing"))?;
+    let g = layer.props.find_group(uid).ok_or_else(|| bad(CMD, "tracker missing"))?;
+    for name in [ct::SOLVE, ct::TRACKS] {
+        if g.prop(name).is_some_and(|p| matches!(&p.value, effectcraft_keyframe::Value::Str(v) if v.len() > MAX_JSON)) {
+            return Err(bad(CMD, "tracking data exceeds the 64 MiB export limit"));
+        }
+    }
+    let params = crate::camera_track::static_params(g);
+    let solve = ct::solve(&params).ok_or_else(|| bad(CMD, "the camera is not solved yet; analyze the tracker first"))?;
+    let (lo, end) = validate::timing(comp, layer, &solve, start)?;
+    let Source { footage, path: source_path, fps: source_fps, count: source_count } = source(s, layer, &solve, path)?;
+    validate::geometry(&solve, sensor)?;
+    let camera = params
+        .get(ct::CAMERA)
+        .map(|v| v.as_f64())
+        .filter(|v| v.is_finite() && *v > 0.0 && *v <= u64::MAX as f64)
+        .and_then(|id| comp.layer(LayerId(id as u64)))
+        .filter(|l| l.is_camera());
+    let warnings = scene_warnings(camera, &solve, footage);
+    let ctx = EvalCtx { expr: s.expr.as_deref(), ..EvalCtx::new(&s.project, cid, comp, lo) };
+    let (frames, world) = bake_frames(&ctx, layer, &solve, camera, &options, footage, source_count)?;
+    let mut points = Vec::new();
+    for point in &solve.points {
+        finite(point.pos.into_iter().chain([point.error as f64]))?;
+        if point.first > point.last || point.last as usize >= solve.frames.len() {
+            return Err(bad(CMD, "invalid solved point frame range; re-analyze the tracker"));
+        }
+        let location = position(world.apply(point.pos), units);
+        finite(location)?;
+        if include_points {
+            points.push(json!({"id": point.id, "location": location, "error": point.error,
+                "first": start.saturating_add(point.first as i64), "last": start.saturating_add(point.last as i64)}));
+        }
+    }
+    let tracks = ct::tracks(&params);
+    if tracks.as_ref().is_some_and(|t| t.tracks.len() > MAX_POINTS || t.tracks.iter().any(|t| t.pts.len() > MAX_FRAMES)) {
+        return Err(bad(CMD, "2D tracks exceed export limits"));
+    }
+    let markers: Vec<Value> = comp
+        .markers
+        .iter()
+        .filter_map(|m| {
+            let frame = start.saturating_add(comp.frame_rate.frame_at(m.time).saturating_sub(comp.frame_rate.frame_at(lo)));
+            if (start..=end).contains(&frame) { Some(json!({"name": m.comment, "frame": frame})) } else { None }
+        })
+        .collect();
+    let payload = json!({"version": 1, "name": format!("{} — {}", s.project.item(cid).map(|i| i.name.as_str()).unwrap_or("Shot"), layer.name),
+        "resolution": solve.size, "fpsNumerator": comp.frame_rate.num, "fpsDenominator": comp.frame_rate.den,
+        "startFrame": start, "endFrame": end, "sensorWidth": sensor, "unitScale": units,
+        "media": {"path": source_path, "kind": if footage.kind == FootageKind::Still {"FILE"} else {"MOVIE"},
+            "fps": source_fps, "nativeRate": footage.native_rate, "pixelAspect": footage.pixel_aspect, "timecode": footage.start_timecode,
+            "frameCount": source_count, "loopCount": footage.loop_count},
+        "frames": frames, "points": points, "markers": markers, "ground": solve.ground.is_some(),
+        "groundSize": world.s * units, "shutter": comp.shutter_angle / 360.0, "shutterPhase": comp.shutter_phase,
+        "solve": solve, "tracks": if include_points { tracks.as_deref() } else { None },
+        "warnings": warnings});
+    let data = serde_json::to_string(&payload).map_err(|e| bad(CMD, format!("cannot serialize scene: {e}")))?;
+    if data.len() > MAX_JSON {
+        return Err(bad(CMD, "scene exceeds the 64 MiB script limit; disable includePoints or split the shot"));
+    }
+    let quoted = serde_json::to_string(&data).map_err(|e| bad(CMD, format!("cannot encode scene: {e}")))?;
+    let script = include_str!("blender_scene.py").replace("__EFFECTCRAFT_DATA__", &quoted);
+    s.services.write_file(path, script.as_bytes()).map_err(|e| bad(CMD, format!("cannot write {path}: {e}")))?;
+    Ok(json!({"path": path, "bytes": script.len(), "frames": frames.len(), "points": points.len(), "warnings": warnings}))
+}
+
+struct Options<'a> {
+    path: &'a str,
+    sensor: f64,
+    units: f64,
+    start: i64,
+    include_points: bool,
+}
+
+impl<'a> Options<'a> {
+    fn parse(p: &'a Value) -> Result<Self> {
+        let path = str_p(p, "path").filter(|p| !p.is_empty() && !p.contains('\0')).ok_or_else(|| bad(CMD, "missing `path` (.py)"))?;
+        if !Path::new(path).extension().is_some_and(|e| e.eq_ignore_ascii_case("py")) {
+            return Err(bad(CMD, "the export path must end in .py"));
+        }
+        let sensor = number(p, "sensorWidth", 36.0, 1.0, 1000.0)?;
+        let units = number(p, "unitScale", 0.01, 0.000_001, 1000.0)?;
+        let start = match p.get("startFrame") {
+            None => 1,
+            Some(v) => v.as_i64().filter(|n| (1..=MAX_FRAME).contains(n)).ok_or_else(|| bad(CMD, "startFrame: expected a positive Blender frame number"))?,
+        };
+        let include_points = match p.get("includePoints") {
+            Some(v) if !v.is_boolean() => return Err(bad(CMD, "includePoints: expected a boolean")),
+            _ => b_p(p, "includePoints").unwrap_or(true),
+        };
+        Ok(Self { path, sensor, units, start, include_points })
+    }
+}
+
+struct Source<'a> {
+    footage: &'a Footage,
+    path: String,
+    fps: f64,
+    count: i64,
+}
+
+fn source<'a>(s: &'a Session, layer: &Layer, solve: &CameraSolve, path: &str) -> Result<Source<'a>> {
+    let footage = match layer.source {
+        LayerSource::Footage { item } => s.project.item(item).and_then(|i| match &i.kind {
+            ItemKind::Footage(f) => Some(f),
+            _ => None,
+        }),
+        _ => None,
+    }
+    .filter(|f| f.has_video && matches!(f.kind, FootageKind::Video | FootageKind::Still));
+    let footage = footage
+        .ok_or_else(|| bad(CMD, "Blender background export needs a video or still-footage layer; render precomps/sequences to a video and track that video"))?;
+    let source_path = media_path(s, &footage.path)?;
+    if Path::new(path) == Path::new(&source_path) {
+        return Err(bad(CMD, "the export path must differ from the source footage"));
+    }
+    if footage.width as f64 != solve.size[0] || footage.height as f64 != solve.size[1] {
+        return Err(bad(CMD, "the analysis image differs from the original footage dimensions; render the tracker's input to a video and track that video"));
+    }
+    let source_fps = footage.frame_rate.as_f64();
+    if footage.frame_rate.num <= 0 || footage.frame_rate.den <= 0 || !source_fps.is_finite() || source_fps <= 0.0 {
+        return Err(bad(CMD, "invalid source footage frame rate"));
+    }
+    // Same frame selection as the media pool: interpreted FPS, rounded per-loop frame count,
+    // clamp to the total loop range, then wrap. Native FPS does not change the frame index.
+    let divisor = (effectcraft_time::TICKS_PER_SECOND as i128).saturating_mul(footage.frame_rate.den as i128);
+    let source_count = (footage.duration.0 as i128).saturating_mul(footage.frame_rate.num as i128).saturating_add(divisor / 2) / divisor;
+    let source_count = if footage.kind == FootageKind::Still { 1 } else { source_count };
+    if !(1..=MAX_FRAME as i128).contains(&source_count) {
+        return Err(bad(CMD, "invalid footage duration or footage exceeds Blender's frame range; trim/render the source video first"));
+    }
+    let source_count = source_count as i64;
+    Ok(Source { footage, path: source_path, fps: source_fps, count: source_count })
+}
+
+fn scene_warnings(camera: Option<&Layer>, solve: &CameraSolve, footage: &Footage) -> Vec<String> {
+    let mut warnings = vec![
+        "Sensor width is assumed (36 mm by default); monocular tracking cannot recover physical sensor size or absolute scene scale.".to_string(),
+        "The original footage is referenced, not embedded or rendered: masks and effects before the tracker are not baked. Relink the video if moving this script.".to_string(),
+    ];
+    if camera.is_none() {
+        warnings
+            .push("No linked tracker camera: focus uses the default scene depth, DOF is off; optical focus cannot be recovered from feature tracks.".into());
+    } else {
+        warnings.push("Focus/iris settings are sampled from the linked camera; pose and lens come from the tracker solve. Blender's physical DOF is an approximation of EffectCraft's blur model.".into());
+    }
+    if solve.distortion.is_some_and(|d| !d.is_none()) {
+        warnings.push("Radial distortion is preserved as metadata (Brown k1/k2, half-diagonal normalization), not applied to Blender's pinhole camera. Use an undistorted plate for exact alignment.".into());
+    }
+    if (footage.pixel_aspect - 1.0).abs() > 1e-6 {
+        warnings.push("The tracker solves square pixels: export uses square pixels; original footage pixel aspect is retained in metadata.".into());
+    }
+    warnings
+}
+
+/// Bake the solved camera and the linked camera's optical settings at exact composition ticks.
+fn bake_frames(
+    ctx0: &EvalCtx<'_>,
+    layer: &Layer,
+    solve: &CameraSolve,
+    camera: Option<&Layer>,
+    options: &Options<'_>,
+    footage: &Footage,
+    source_count: i64,
+) -> Result<(Vec<Value>, linalg::Similarity)> {
+    let comp = ctx0.comp;
+    let lo = ctx0.time;
+    let fd = comp.frame_duration();
+    let sensor = options.sensor;
+    let units = options.units;
+    let start = options.start;
+    let first = solve.frames.first().ok_or_else(|| bad(CMD, "the camera solve is empty"))?;
+    let m = ctx0.world_matrix(layer).0;
+    let layer_scale = m[0][0].hypot(m[1][0]);
+    finite([layer_scale])?;
+    if layer_scale <= 1e-9 {
+        return Err(bad(CMD, "the tracked layer has zero scale"));
+    }
+    let world = solve.world([comp.width as f64, comp.height as f64], first.focal * layer_scale);
+    finite([world.s * units])?;
+    let mut frames = Vec::with_capacity(solve.frames.len());
+    for (i, frame) in solve.frames.iter().enumerate() {
+        let time = Tick(lo.0.saturating_add(fd.0.saturating_mul(i as i64)));
+        let ctx = ctx0.at(time);
+        let pose = linalg::mm(&world.r, &linalg::mt(&frame.r()));
+        let right = position(linalg::mv(&pose, [1.0, 0.0, 0.0]), 1.0);
+        let up = position(linalg::mv(&pose, [0.0, -1.0, 0.0]), 1.0);
+        let back = position(linalg::mv(&pose, [0.0, 0.0, -1.0]), 1.0);
+        let location = position(world.apply(frame.center), units);
+        let lens = frame.focal * sensor / solve.size[0];
+        let opts = camera.and_then(|l| l.props.sub("cameraOptions").map(|g| (l, g)));
+        let value = |key: &str, fallback: f64| opts.map(|(l, g)| ctx.f(l, g, key, fallback)).unwrap_or(fallback);
+        let focus = value("focusDistance", world.s) * units;
+        let aperture = value("aperture", 0.0);
+        let zoom = value("zoom", frame.focal * layer_scale);
+        // Match Camera Settings' f-stop conversion: focal_for_zoom uses a 36 mm film width,
+        // and the aperture UI is mm scaled by comp_width / 1920 (not a world-space diameter).
+        let aperture_mm = aperture * 1920.0 / comp.width as f64;
+        let fstop = if aperture_mm > 0.0 { (zoom * 36.0 / comp.width as f64) / aperture_mm } else { 2.8 };
+        let rotation = value("irisRotation", 0.0).to_radians();
+        let ratio = value("irisAspectRatio", 1.0);
+        let shape = opts.map(|(l, g)| ctx.e(l, g, "irisShape")).unwrap_or(0);
+        let blades = match shape {
+            0 => 4,
+            1..=8 => shape.saturating_add(2),
+            _ => return Err(bad(CMD, "invalid iris shape")),
+        };
+        let dof = opts.is_some_and(|(l, g)| ctx.b(l, g, "dof")) && aperture > 0.0 && value("blurLevel", 100.0) > 0.0;
+        let source_time = ctx.source_time(layer);
+        let source_frame = if footage.kind == FootageKind::Still {
+            0
+        } else {
+            footage.frame_rate.frame_at(source_time).clamp(0, source_count.saturating_mul(footage.loop_count.max(1) as i64).saturating_sub(1)) % source_count
+        };
+        finite(location.into_iter().chain([focus, aperture, zoom, fstop, rotation, ratio, value("blurLevel", 100.0), value("irisRoundness", 0.0)]))?;
+        if focus <= 0.0 || !(0.01..=100.0).contains(&ratio) || !(0.01..=1e6).contains(&fstop) {
+            return Err(bad(CMD, "focus, f-stop or iris aspect is outside Blender's supported range"));
+        }
+        frames.push(json!({"frame": start + i as i64, "timeTicks": time.0, "sourceFrame": source_frame,
+            "location": location, "rotation": [right, up, back], "lens": lens, "focus": focus, "dof": dof,
+            "fstop": fstop, "blades": blades, "irisRotation": rotation, "irisRatio": ratio,
+            "sourceAperture": aperture, "sourceZoom": zoom,
+            "blurLevel": value("blurLevel", 100.0), "irisRoundness": value("irisRoundness", 0.0)}));
+    }
+    Ok((frames, world))
+}
@@ -0,0 +1,71 @@
+//! Validate solved geometry and its correspondence to the current layer timing.
+
+use effectcraft_project::{Comp, Layer};
+use effectcraft_time::Tick;
+use effectcraft_track::camtrack::{CameraSolve, linalg};
+
+use super::{CMD, MAX_FRAME, MAX_FRAMES, MAX_POINTS, bad, finite};
+use crate::Result;
+
+pub(super) fn timing(comp: &Comp, layer: &Layer, solve: &CameraSolve, start: i64) -> Result<(Tick, i64)> {
+    if solve.frames.len() > MAX_FRAMES || solve.points.len() > MAX_POINTS {
+        return Err(bad(CMD, "export is limited to 100,000 frames and 100,000 points; split the shot"));
+    }
+    if solve.size.iter().any(|v| !v.is_finite() || *v < 4.0 || *v > 65_536.0 || v.fract() != 0.0) {
+        return Err(bad(CMD, "invalid tracking resolution (expected 4..65536 whole pixels)"));
+    }
+    let fps = comp.frame_rate.as_f64();
+    if comp.frame_rate.num <= 0 || comp.frame_rate.den <= 0 || !fps.is_finite() || !(1.0..=1000.0).contains(&fps) {
+        return Err(bad(CMD, "invalid composition frame rate (expected 1..1000 fps)"));
+    }
+    let end = start
+        .checked_add(solve.frames.len() as i64)
+        .and_then(|n| n.checked_sub(1))
+        .filter(|n| *n <= MAX_FRAME)
+        .ok_or_else(|| bad(CMD, "the baked animation exceeds Blender's frame range"))?;
+    finite([solve.start, solve.frame_duration, solve.average_error, layer.stretch, comp.shutter_angle, comp.shutter_phase])?;
+    if layer.stretch == 0.0 || comp.width == 0 || comp.height == 0 {
+        return Err(bad(CMD, "invalid composition dimensions or zero layer stretch"));
+    }
+    let lo = comp.frame_rate.snap_nearest(layer.in_point.max(Tick::ZERO));
+    let hi = layer.out_point.min(comp.duration);
+    let fd = comp.frame_duration();
+    if fd.0 <= 0 || lo >= hi {
+        return Err(bad(CMD, "the tracked layer has no active frames"));
+    }
+    let expected = ((hi.0 as i128 - lo.0 as i128 + fd.0 as i128 - 1) / fd.0 as i128) as u128;
+    if expected != solve.frames.len() as u128 {
+        return Err(bad(CMD, "the solve no longer matches the layer's frame range; re-analyze the tracker"));
+    }
+    let dt = (layer.layer_time(lo + fd) - layer.layer_time(lo)).seconds();
+    if (solve.start - layer.layer_time(lo).seconds()).abs() > 1e-6 || solve.frames.len() > 1 && (solve.frame_duration - dt).abs() > 1e-6 {
+        return Err(bad(CMD, "the solve no longer matches the layer's timing; re-analyze the tracker"));
+    }
+    Ok((lo, end))
+}
+
+pub(super) fn geometry(solve: &CameraSolve, sensor: f64) -> Result<()> {
+    for frame in &solve.frames {
+        finite(frame.rot.into_iter().chain(frame.center).chain([frame.focal]))?;
+        if !frame.solved || frame.focal <= 0.0 {
+            return Err(bad(CMD, "the solve contains unsolved frames or invalid focal lengths; re-analyze the tracker"));
+        }
+        let mm = sensor * frame.focal / solve.size[0];
+        if !(1.0..=5000.0).contains(&mm) {
+            return Err(bad(CMD, "lens outside Blender's 1..5000 mm range; choose another sensorWidth"));
+        }
+    }
+    if let Some(ground) = &solve.ground {
+        finite(ground.origin.into_iter().chain(ground.normal).chain(ground.x_axis))?;
+        if (linalg::norm(ground.normal) - 1.0).abs() > 1e-4
+            || (linalg::norm(ground.x_axis) - 1.0).abs() > 1e-4
+            || linalg::dot(ground.normal, ground.x_axis).abs() > 1e-4
+        {
+            return Err(bad(CMD, "invalid ground-plane basis; set the ground plane again"));
+        }
+    }
+    if let Some(d) = &solve.distortion {
+        finite([d.k1, d.k2, d.radius])?;
+    }
+    Ok(())
+}
@@ -0,0 +1,204 @@
+# EffectCraft camera tracker → Blender, original code under MIT OR Apache-2.0.
+# Run in Blender's Scripting workspace (Open, Run Script), or:
+# blender --background --python "Tracked Scene.py"
+# Creates a NEW scene; existing scenes and objects are preserved. Save the .blend yourself.
+# Public API types: bpy.types.Camera, bpy.types.ImageUser
+import json
+import math
+import os
+
+import bpy
+from mathutils import Matrix
+
+DATA = json.loads(__EFFECTCRAFT_DATA__)
+
+
+def _curves(owner):
+    """Blender 4.0–4.3 legacy actions and 4.4+/5.x layered actions."""
+    anim = owner.animation_data
+    if anim is None or anim.action is None:
+        return
+    action = anim.action
+    if getattr(action, "is_action_layered", False):
+        for layer in action.layers:
+            for strip in layer.strips:
+                if strip.type == 'KEYFRAME':
+                    bag = strip.channelbag(anim.action_slot)
+                    if bag is not None:
+                        yield from bag.fcurves
+    else:
+        yield from action.fcurves
+
+
+def _interpolation(owner):
+    for curve in _curves(owner):
+        # Footage indices and discrete switches must never interpolate between frames.
+        stepped = ("frame_offset" in curve.data_path or "use_dof" in curve.data_path
+                   or "aperture_blades" in curve.data_path)
+        for key in curve.keyframe_points:
+            key.interpolation = 'CONSTANT' if stepped else 'LINEAR'
+
+
+def _media_path():
+    original = DATA["media"]["path"]
+    candidates = [original]
+    # When sharing, place the video alongside the script or the .blend and run again.
+    script_path = globals().get("__file__", "")
+    if script_path:
+        candidates.append(os.path.join(os.path.dirname(os.path.abspath(script_path)),
+                                       os.path.basename(original)))
+    if bpy.data.filepath:
+        candidates.append(os.path.join(os.path.dirname(bpy.data.filepath),
+                                       os.path.basename(original)))
+    return next((p for p in candidates if os.path.isfile(p)), None)
+
+
+def import_scene():
+    if bpy.app.version < (4, 0, 0):
+        raise RuntimeError("EffectCraft scene import requires Blender 4.0 or newer")
+    scene = bpy.data.scenes.new(DATA["name"])
+    scene.frame_start = DATA["startFrame"]
+    scene.frame_end = DATA["endFrame"]
+    fps = DATA["fpsNumerator"] / DATA["fpsDenominator"]
+    scene.render.fps = max(1, round(fps))
+    scene.render.fps_base = scene.render.fps / fps
+    scene.render.resolution_x, scene.render.resolution_y = map(int, DATA["resolution"])
+    scene.render.resolution_percentage = 100
+    # The tracker assumes square pixels, regardless of the source's interpretation metadata.
+    scene.render.pixel_aspect_x = scene.render.pixel_aspect_y = 1.0
+    scene.render.film_transparent = True
+    scene.render.motion_blur_shutter = max(0.0, min(2.0, DATA["shutter"]))
+    scene.unit_settings.system = 'METRIC'
+    scene.unit_settings.scale_length = 1.0
+    scene["effectcraft_unit_scale"] = DATA["unitScale"]
+    scene["effectcraft_scale_is_arbitrary"] = True
+    scene["effectcraft_shutter_phase_degrees"] = DATA["shutterPhase"]
+
+    collection = bpy.data.collections.new("EffectCraft Tracking")
+    scene.collection.children.link(collection)
+    camera_data = bpy.data.cameras.new("3D Tracker Camera")
+    camera = bpy.data.objects.new("3D Tracker Camera", camera_data)
+    collection.objects.link(camera)
+    scene.camera = camera
+    camera.rotation_mode = 'QUATERNION'
+    camera_data.type = 'PERSP'
+    camera_data.sensor_fit = 'HORIZONTAL'
+    camera_data.sensor_width = DATA["sensorWidth"]
+    camera_data.sensor_height = (DATA["sensorWidth"] * DATA["resolution"][1]
+                                 / DATA["resolution"][0])
+    camera_data.show_background_images = True
+    camera_data.show_limits = True
+    extent = max([DATA["groundSize"], 1.0]
+                 + [math.dist(p["location"], f["location"])
+                    for p in DATA["points"][::max(1, len(DATA["points"]) // 100)]
+                    for f in DATA["frames"][::max(1, len(DATA["frames"]) // 10)]])
+    camera_data.clip_start = max(0.00001, min(0.1, extent / 10000.0))
+    camera_data.clip_end = max(1000.0, extent * 10.0)
+
+    previous = None
+    for sample in DATA["frames"]:
+        frame = sample["frame"]
+        camera.location = sample["location"]
+        # Exported right/up/back vectors are COLUMNS of Blender's local → world basis.
+        quaternion = Matrix(sample["rotation"]).transposed().to_quaternion()
+        if previous is not None and previous.dot(quaternion) < 0:
+            quaternion.negate()
+        camera.rotation_quaternion = quaternion
+        previous = quaternion.copy()
+        camera.keyframe_insert(data_path="location", frame=frame)
+        camera.keyframe_insert(data_path="rotation_quaternion", frame=frame)
+        camera_data.lens = sample["lens"]
+        camera_data.keyframe_insert(data_path="lens", frame=frame)
+        camera_data.dof.use_dof = sample["dof"]
+        camera_data.dof.focus_distance = sample["focus"]
+        camera_data.dof.aperture_fstop = sample["fstop"]
+        camera_data.dof.aperture_blades = sample["blades"]
+        camera_data.dof.aperture_rotation = (sample["irisRotation"] + math.pi) % math.tau - math.pi
+        camera_data.dof.aperture_ratio = sample["irisRatio"]
+        for prop in ("use_dof", "focus_distance", "aperture_fstop", "aperture_blades",
+                     "aperture_rotation", "aperture_ratio"):
+            camera_data.keyframe_insert(data_path="dof." + prop, frame=frame)
+
+    path = _media_path()
+    if path is not None:
+        try:
+            image = bpy.data.images.load(path, check_existing=False)
+            image.source = DATA["media"]["kind"]
+            background = camera_data.background_images.new()
+            background.source = 'IMAGE'
+            background.image = image
+            background.alpha = 1.0
+            background.display_depth = 'BACK'
+            background.frame_method = 'STRETCH'
+            user = background.image_user
+            user.use_auto_refresh = True
+            user.use_cyclic = False
+            user.frame_start = DATA["startFrame"]
+            user.frame_duration = max(1, min(1048574, image.frame_duration))
+            if image.source == 'MOVIE':
+                for sample in DATA["frames"]:
+                    # Blender uses 1-based image frames; sourceFrame is 0-based.
+                    user.frame_offset = sample["sourceFrame"] - (sample["frame"] - user.frame_start)
+                    camera_data.keyframe_insert(
+                        data_path="background_images[0].image_user.frame_offset",
+                        frame=sample["frame"])
+        except (RuntimeError, ValueError, OSError) as error:
+            DATA["warnings"].append("Blender could not load the background video: " + str(error))
+    else:
+        DATA["warnings"].append("Video not found: " + DATA["media"]["path"]
+                                + ". Place it beside this script or relink the camera background.")
+
+    if DATA["points"]:
+        mesh = bpy.data.meshes.new("Solved Track Points")
+        mesh.from_pydata([p["location"] for p in DATA["points"]], [], [])
+        mesh.update()
+        cloud = bpy.data.objects.new("Solved Track Points", mesh)
+        collection.objects.link(cloud)
+        cloud.show_in_front = True
+        cloud.hide_render = True
+        for name, kind, key in (("track_id", 'INT', "id"), ("reprojection_error", 'FLOAT', "error"),
+                                ("first_frame", 'INT', "first"), ("last_frame", 'INT', "last")):
+            attr = mesh.attributes.new(name=name, type=kind, domain='POINT')
+            for dest, point in zip(attr.data, DATA["points"]):
+                # Track IDs are u32 in EffectCraft; keep the full IDs in the JSON text too.
+                dest.value = point[key] if kind == 'FLOAT' else min(2147483647, point[key])
+
+    if DATA["ground"]:
+        size = DATA["groundSize"]
+        mesh = bpy.data.meshes.new("Solved Ground Plane")
+        mesh.from_pydata([(-size, -size, 0), (size, -size, 0),
+                          (size, size, 0), (-size, size, 0)], [], [(0, 1, 2, 3)])
+        mesh.update()
+        ground = bpy.data.objects.new("Solved Ground Plane", mesh)
+        collection.objects.link(ground)
+        ground.display_type = 'WIRE'
+        ground.hide_render = True
+    for marker in DATA["markers"]:
+        scene.timeline_markers.new(marker["name"], frame=marker["frame"])
+
+    _interpolation(camera)
+    _interpolation(camera_data)
+    metadata = bpy.data.texts.new("EffectCraft Tracking Metadata.json")
+    metadata.write(json.dumps(DATA, ensure_ascii=False, indent=2))
+    scene["effectcraft_metadata_text"] = metadata.name
+    camera_data["effectcraft_average_error_pixels"] = DATA["solve"]["averageError"]
+    camera_data["effectcraft_solve_method"] = DATA["solve"]["methodUsed"]
+    camera_data["effectcraft_focus_source"] = "See warnings in " + metadata.name
+    distortion = DATA["solve"].get("distortion")
+    if distortion:
+        for key in ("k1", "k2", "radius"):
+            camera_data["effectcraft_distortion_" + key] = distortion[key]
+    if bpy.context.window is not None:
+        bpy.context.window.scene = scene
+        for area in bpy.context.window.screen.areas:
+            if area.type == 'VIEW_3D':
+                area.spaces.active.region_3d.view_perspective = 'CAMERA'
+    scene.frame_set(scene.frame_start)
+    for warning in DATA["warnings"]:
+        print("EffectCraft: " + warning)
+    print("EffectCraft: imported", len(DATA["frames"]), "baked camera frames into", scene.name)
+    return scene
+
+
+if __name__ == "__main__":
+    EFFECTCRAFT_SCENE = import_scene()
@@ -42,11 +42,25 @@ pub fn specs() -> Vec<CommandSpec> {
            create_from_solve
        ),
        cmd!("camera.create", "Create Camera", [], None, "{layer?, effect?}", has_comp, |s, p| create_from_solve(s, &with_kind(p, "camera"))),
+        cmd!(
+            "camera.exportBlender",
+            "Export Scene to Blender...",
+            [],
+            None,
+            "{path: .py, comp?, layer?, effect?, sensorWidth?: mm (default 36), unitScale?: Blender units per comp pixel (default 0.01), startFrame?: positive integer (default 1), includePoints?: true}",
+            has_comp,
+            export_blender
+        ),
        cmd!("camera.setGroundPlane", "Set Ground Plane and Origin", [], None, "{points?: [id] (default: selected), layer?, effect?}", has_comp, set_ground),
        cmd!("camera.deletePoints", "Delete Selected Points", [], None, "{points?: [id] (default: selected), layer?, effect?, wait?}", has_comp, delete_points),
    ]
 }

+fn export_blender(s: &mut Session, p: &Value) -> Result<Value> {
+    let (cid, lid, uid) = ct_p(s, p, "camera.exportBlender")?;
+    super::blender::export(s, p, cid, lid, uid)
+}
+
 fn with_kind(p: &Value, kind: &str) -> Value {
    let mut q = p.clone();
    if !q.is_object() {
@@ -35,7 +35,7 @@ fn apply_settings(c: &mut Comp, p: &Value) {
        let dx = (c.width as f64 - ow as f64) * (a % 3) as f64 / 2.0;
        let dy = (c.height as f64 - oh as f64) * (a / 3) as f64 / 2.0;
        if dx != 0.0 || dy != 0.0 {
-            for l in c.layers.iter_mut().filter(|l| l.parent.is_none()) {
+            for l in c.layers.iter_mut_where(|l| l.parent.is_none()) {
                if let Some(tr) = l.transform_mut() {
                    super::layer::offset_position(tr, dx, dy);
                }
@@ -1,11 +1,11 @@
-//! Composition menu, part two: crop to region of interest / layer bounds, Save Frame As ▸ File,
-//! Copy Frame to Clipboard, Responsive Design — Time.
+//! Composition menu, part two: crop to region of interest / layer bounds, Scale Composition, Save
+//! Frame As ▸ File, Copy Frame to Clipboard, Responsive Design — Time.

 use effectcraft_project::Marker;
 use effectcraft_time::Tick;
 use serde_json::{Value, json};

-use super::{CommandSpec, always, bad, comp_id, f_p, has_comp, has_layers, layers_p, str_p};
+use super::{CommandSpec, always, b_p, bad, comp_id, f_p, has_comp, has_layers, layers_p, str_p};
 use crate::prefs::CompPreset;
 use crate::{EngineError, Result, Session, cmd, query};

@@ -25,7 +25,7 @@ fn crop(s: &mut Session, cid: effectcraft_project::ItemId, r: [f64; 4], label: &
        let (old_w, old_h) = (c.width, c.height);
        c.width = w;
        c.height = h;
-        for l in c.layers.iter_mut().filter(|l| l.parent.is_none()) {
+        for l in c.layers.iter_mut_where(|l| l.parent.is_none()) {
            if let Some(tr) = l.transform_mut() {
                super::layer::offset_position(tr, -x, -y);
            }
@@ -71,6 +71,164 @@ fn crop_to_layers(s: &mut Session, p: &Value) -> Result<Value> {
    crop(s, cid, [x0, y0, b[2].ceil() - x0, b[3].ceil() - y0], "Crop Comp to Selected Layer(s) Bounds")
 }

+/// Multiply a property's value, every key, its spatial tangents and its speeds by `f`.
+fn scale_prop(pr: &mut effectcraft_project::Property, f: f64) {
+    use effectcraft_keyframe::Value as KV;
+    let mul = |v: &KV| match v {
+        KV::Scalar(x) => KV::Scalar(x * f),
+        KV::Vec2(a) => KV::Vec2(a.map(|x| x * f)),
+        KV::Vec3(a) => KV::Vec3(a.map(|x| x * f)),
+        other => other.clone(),
+    };
+    pr.value = mul(&pr.value);
+    for k in &mut pr.keys {
+        k.value = mul(&k.value);
+        k.spatial_in = k.spatial_in.map(|x| x * f);
+        k.spatial_out = k.spatial_out.map(|x| x * f);
+        for e in k.in_ease.iter_mut().chain(&mut k.out_ease) {
+            e.speed *= f;
+        }
+    }
+}
+
+/// Multiply only the Z of a 3D value (and of its keys and spatial tangents) by `f`. Speeds follow:
+/// a spatial side's speed by how much the path's direction there stretches, so the ease keeps
+/// its shape; a per-dimension one (Scale) by `f` for Z only.
+fn scale_prop_z(pr: &mut effectcraft_project::Property, f: f64) {
+    use effectcraft_keyframe::Value as KV;
+    let stretch = |v: [f64; 3]| {
+        let n = v[0].hypot(v[1]).hypot(v[2]);
+        if n > 1e-12 && n.is_finite() { v[0].hypot(v[1]).hypot(v[2] * f) / n } else { 1.0 }
+    };
+    let pos = |k: &effectcraft_project::Keyframe| k.value.as_vec3();
+    let sub = |a: [f64; 3], b: [f64; 3]| [a[0] - b[0], a[1] - b[1], a[2] - b[2]];
+    let is_zero = |v: [f64; 3]| v.iter().all(|x| x.abs() <= 1e-12);
+    // Read every side's direction before anything changes (auto tangents come from the neighbours).
+    let sides: Vec<(f64, f64)> = (0..pr.keys.len())
+        .map(|i| {
+            let (tin, tout) = effectcraft_keyframe::spatial_tangents(&pr.keys, i);
+            let here = pr.keys.get(i).map(pos).unwrap_or_default();
+            let chord = |j: Option<usize>| j.and_then(|j| pr.keys.get(j)).map(|k| sub(pos(k), here)).unwrap_or_default();
+            let tin = if is_zero(tin) { chord(i.checked_sub(1)) } else { tin };
+            let tout = if is_zero(tout) { chord(Some(i + 1)) } else { tout };
+            (stretch(tin), stretch(tout))
+        })
+        .collect();
+    let spatial = pr.spatial;
+    let mul = |v: &mut KV| {
+        if let KV::Vec3(a) = v {
+            a[2] *= f;
+        }
+    };
+    mul(&mut pr.value);
+    for (k, (s_in, s_out)) in pr.keys.iter_mut().zip(sides) {
+        mul(&mut k.value);
+        k.spatial_in[2] *= f;
+        k.spatial_out[2] *= f;
+        if spatial {
+            k.in_ease.iter_mut().for_each(|e| e.speed *= s_in);
+            k.out_ease.iter_mut().for_each(|e| e.speed *= s_out);
+        } else {
+            // A shorter list lends its first ease to Z (`effective_ease`): give Z its own.
+            for list in [&mut k.in_ease, &mut k.out_ease] {
+                if let Some(&first) = list.first() {
+                    list.resize(list.len().max(3), first);
+                }
+                if let Some(e) = list.get_mut(2) {
+                    e.speed *= f;
+                }
+            }
+        }
+    }
+}
+
+/// Scale Composition (After Effects ships it as File ▸ Scripts ▸ Scale Composition.jsx): the comp
+/// and its contents grow or shrink by one factor, keys included, in one undo step. Layers whose
+/// parent has a Scale follow that parent; everything else scales its Position (and Point of
+/// Interest) and Scale. Anchor Point, masks, shapes and effects live in layer space and follow the
+/// layer's Scale. Cameras scale their Zoom so 3D layers keep their place in the frame; a 2D parent
+/// carries no depth, so its 3D children scale their Z themselves.
+fn scale_comp(s: &mut Session, p: &Value) -> Result<Value> {
+    const C: &str = "comp.scale";
+    let cid = comp_id(s, p)?;
+    let comp = s.project.comp(cid).ok_or(EngineError::NoComp)?;
+    let (ow, oh) = (f64::from(comp.width), f64::from(comp.height));
+    // The three are alternatives: with two, one would be ignored without a word.
+    if ["factor", "width", "height"].iter().filter(|k| f_p(p, k).is_some()).count() > 1 {
+        return Err(bad(C, "pass only one of `factor`, `width` or `height`"));
+    }
+    let f = match (f_p(p, "factor"), f_p(p, "width"), f_p(p, "height")) {
+        (Some(f), ..) => f,
+        (None, Some(w), _) => w / ow,
+        (None, None, Some(h)) => h / oh,
+        _ => return Err(bad(C, "pass `factor`, `width` or `height`")),
+    };
+    let (w, h) = ((ow * f).round(), (oh * f).round());
+    let max = f64::from(effectcraft_project::limits::MAX_SIZE);
+    if !f.is_finite() || f <= 0.0 || !(4.0..=max).contains(&w) || !(4.0..=max).contains(&h) {
+        return Err(bad(C, format!("the composition would be {w}×{h}: width and height run from 4 to 30,000 px")));
+    }
+    let (w, h) = (w as u32, h as u32);
+    let active = s.active_comp_id() == Some(cid);
+    s.edit("Scale Composition", None, |proj, st| {
+        let c = proj.comp_mut(cid).ok_or(EngineError::NoComp)?;
+        // An ancestor's Scale carries its descendants (X and Y only when that ancestor is 2D),
+        // through cameras and lights too: the renderer applies every ancestor's transform.
+        let chain: std::collections::HashMap<_, _> =
+            c.layers.iter().map(|l| (l.id, (l.transform().is_some_and(|tr| tr.get("scale").is_some()), l.is_3d(), l.parent))).collect();
+        // (X and Y carried, Z carried); bounded, as parent chains in a file can loop.
+        let carried = |mut cur: Option<effectcraft_project::LayerId>| {
+            let (mut xy, mut z) = (false, false);
+            for _ in 0..64 {
+                let Some(&(has_scale, three_d, up)) = cur.and_then(|id| chain.get(&id)) else { break };
+                xy |= has_scale;
+                z |= has_scale && three_d;
+                cur = up;
+            }
+            (xy, z)
+        };
+        for l in &mut c.layers {
+            let (xy_carried, z_carried) = carried(l.parent);
+            let three_d = l.is_3d();
+            let Some(tr) = l.transform_mut() else { continue };
+            if !xy_carried {
+                for name in ["position", "positionX", "positionY", "positionZ", "poi", "scale"] {
+                    if let Some(pr) = tr.get_mut(name) {
+                        scale_prop(pr, f);
+                    }
+                }
+            } else if three_d && !z_carried {
+                if let Some(pr) = tr.get_mut("positionZ") {
+                    scale_prop(pr, f);
+                }
+                for name in ["position", "poi", "scale"] {
+                    if let Some(pr) = tr.get_mut(name) {
+                        scale_prop_z(pr, f);
+                    }
+                }
+            }
+            if let Some(cam) = l.props.sub_mut("cameraOptions") {
+                for name in ["zoom", "focusDistance", "aperture"] {
+                    if let Some(pr) = cam.get_mut(name) {
+                        scale_prop(pr, f);
+                    }
+                }
+            }
+        }
+        // Percentage guides keep their percent.
+        for g in c.guides.iter_mut().filter(|g| !g.percent) {
+            g.position *= f;
+        }
+        c.width = w;
+        c.height = h;
+        if active && let Some(r) = &mut st.region_of_interest {
+            *r = r.map(|v| v * f);
+        }
+        Ok(())
+    })?;
+    Ok(json!({"width": w, "height": h, "factor": f}))
+}
+
 /// Encode straight 8-bit RGBA as PNG.
 pub(crate) fn encode_png(rgba: &[u8], w: u32, h: u32) -> std::result::Result<Vec<u8>, String> {
    use image::ImageEncoder;
@@ -82,7 +240,7 @@ pub(crate) fn encode_png(rgba: &[u8], w: u32, h: u32) -> std::result::Result<Vec
 /// Save Frame As ▸ File with `queue`: a Render Queue item for the current frame, from the Frame
 /// Default templates (Edit ▸ Templates).
 fn queue_frame(s: &mut Session, p: &Value) -> Result<Value> {
-    use effectcraft_project::render_queue::{RenderQueueItem, TimeSpan};
+    use effectcraft_project::render_queue::{Channels, RenderQueueItem, TimeSpan};
    use effectcraft_project::render_templates::TemplateSlot;
    let cid = comp_id(s, p)?;
    let comp = s.project.comp(cid).ok_or(EngineError::NoComp)?;
@@ -91,10 +249,16 @@ fn queue_frame(s: &mut Session, p: &Value) -> Result<Value> {
    it.settings = s.project.render_templates.default_render_settings(TemplateSlot::Still);
    it.settings.time_span = TimeSpan::Custom { start: t, end: t + comp.frame_duration() };
    it.output = s.project.render_templates.default_output_module(TemplateSlot::Still);
+    if b_p(p, "transparent") == Some(false) {
+        it.output.channels = Channels::Rgb;
+    }
    if let Some(path) = str_p(p, "path") {
        it.output.output = path.to_string();
-    } else if !it.output.format.is_sequence() {
-        it.output.output = "[compName]_frame.[fileExtension]".into();
+    } else {
+        if !it.output.format.is_sequence() {
+            it.output.output = "[compName]_frame.[fileExtension]".into();
+        }
+        s.avoid_sources(&mut it);
    }
    let id = s.edit("Save Frame As", None, |proj, _| {
        it.id = proj.render_queue.iter().map(|i| i.id).max().unwrap_or(0) + 1;
@@ -107,7 +271,7 @@ fn queue_frame(s: &mut Session, p: &Value) -> Result<Value> {
 }

 fn save_frame(s: &mut Session, p: &Value) -> Result<Value> {
-    if p.get("queue").and_then(Value::as_bool) == Some(true) {
+    if b_p(p, "queue") == Some(true) {
        return queue_frame(s, p);
    }
    let path = str_p(p, "path").ok_or_else(|| bad("comp.saveFrameAs", "missing `path` (.png)"))?.to_string();
@@ -117,7 +281,7 @@ fn save_frame(s: &mut Session, p: &Value) -> Result<Value> {
    let scale = f_p(p, "scale").unwrap_or(1.0).clamp(0.01, 4.0);
    let bg = comp.background;
    let img = s.render(cid, t, effectcraft_render::RenderOpts { scale, backend: effectcraft_render::Backend::Auto, ..Default::default() });
-    let rgba = img.to_rgba8_over(bg);
+    let rgba = if b_p(p, "transparent") == Some(false) { img.to_rgba8_over(bg) } else { img.to_rgba8() };
    let png = encode_png(&rgba, img.width, img.height).map_err(|e| EngineError::Other(format!("PNG encoding failed: {e}")))?;
    s.services.write_file(&path, &png).map_err(|e| EngineError::Other(format!("cannot write {path}: {e}")))?;
    s.toast(format!("Saved frame to {path}"));
@@ -230,12 +394,21 @@ pub fn specs() -> Vec<CommandSpec> {
    vec![
        cmd!("comp.cropToRegionOfInterest", "Crop Comp to Region of Interest", ["Composition"], None, "{comp?}", has_roi, crop_to_roi),
        cmd!("comp.cropToLayerBounds", "Crop Comp to Selected Layer(s) Bounds", ["Composition"], None, "{layers?}", has_layers, crop_to_layers),
+        cmd!(
+            "comp.scale",
+            "Scale Composition",
+            [],
+            None,
+            "{comp?, factor? (2 = twice the size) | width? | height? (the other side keeps the aspect ratio)}",
+            has_comp,
+            scale_comp
+        ),
        cmd!(
            "comp.saveFrameAs",
            "File...",
            ["Composition", "Save Frame As"],
            Some("Cmd+Alt+S"),
-            "{path (.png; with queue: an output path or template), time?, scale?, queue?: bool (add a Render Queue item from the Frame Default templates instead of writing now)}",
+            "{path (.png; with queue: an output path or template), time?, scale?, queue?: bool (add a Render Queue item from the Frame Default templates instead of writing now), transparent?: bool (default true)}",
            has_comp,
            save_frame
        ),
@@ -170,6 +170,21 @@ pub struct FillPlan {
    pub dir: String,
 }

+/// The fill holds every frame as float RGBA (16 bytes a pixel), its hole mask (1) and the filled
+/// copy (16) until it finishes (#1789): when even that is more than `available`, the error to
+/// report up front, instead of running out of memory partway through.
+fn memory_shortfall(frames: usize, w: u32, h: u32, available: u64) -> Option<String> {
+    let need = (frames as u64).saturating_mul(u64::from(w)).saturating_mul(u64::from(h)).saturating_mul(33);
+    (need > available).then(|| {
+        let gb = |b: u64| b as f64 / 1e9;
+        format!(
+            "Content-Aware Fill of {frames} frames at {w}×{h} needs at least {:.1} GB of memory, and {:.1} GB is free: fill a shorter range (set the work area and choose Work Area) or close other applications",
+            gb(need),
+            gb(available)
+        )
+    })
+}
+
 /// Run a fill: the layer's frames (rendered in passes with a job worker's GPU), the fill, the
 /// PNG sequence written into `plan.dir` (`Services::store_file`). Returns the files.
 #[allow(clippy::too_many_arguments)]
@@ -275,6 +290,9 @@ fn generate(s: &mut Session, p: &Value) -> Result<Value> {
    }
    let (fa, fb) = (fr.frame_at(fr.snap_nearest(a)), fr.frame_at(b - Tick(1)));
    let times: Vec<Tick> = (fa..=fb).map(|f| fr.tick_of(f)).collect();
+    if let Some(e) = crate::sysinfo::memory().and_then(|m| memory_shortfall(times.len(), w, h, m.available)) {
+        return Err(bad(c, e));
+    }
    let opts = FillOpts {
        method: FillMethod::from_name(&st.method).unwrap_or_default(),
        lighting: lighting(&st.lighting_correction).unwrap_or(0.0),
@@ -424,3 +442,18 @@ pub fn specs() -> Vec<CommandSpec> {
        },
    ]
 }
+
+#[cfg(test)]
+mod tests {
+    use super::memory_shortfall;
+
+    /// #1789: 10 s of 1080p30 (300 frames) needs at least 20 GB, which 4 GB free can't hold.
+    #[test]
+    fn a_fill_that_cannot_fit_in_memory_is_refused_up_front() {
+        let e = memory_shortfall(300, 1920, 1080, 4_000_000_000).expect("refused");
+        assert!(e.contains("300 frames") && e.contains("Work Area"), "{e}");
+        assert_eq!(memory_shortfall(30, 1920, 1080, 4_000_000_000), None, "a second of it fits");
+        // Hostile sizes saturate instead of overflowing.
+        assert!(memory_shortfall(usize::MAX, u32::MAX, u32::MAX, u64::MAX - 1).is_some());
+    }
+}
@@ -1,14 +1,17 @@
 //! Layer ▸ Create: Convert to Editable Text (Photoshop type layers), Create Shapes from Text,
-//! Create Masks from Text and Create Shapes from Vector Layer (SVG footage).
+//! Create Masks from Text, Create Shapes from Vector Layer (SVG footage) and Create 3D Layer
+//! Instance (a 2D copy of a 3D model layer that 2D effects can be applied to).

 use effectcraft_color::Label;
+use effectcraft_keyframe::Value as KV;
+use effectcraft_project::build::{self, Ids};
 use effectcraft_project::{ItemKind, LayerSource, Solid};
 use serde_json::{Value, json};

 use super::{CommandSpec, bad, has_layers, layers_p, str_p};
 use crate::{EngineError, Result, Session, cmd};

-const OPS: &str = "editableText|shapesFromText|masksFromText|shapesFromVector";
+const OPS: &str = "editableText|shapesFromText|masksFromText|shapesFromVector|instance3d";

 fn create(s: &mut Session, p: &Value) -> Result<Value> {
    let op = str_p(p, "op").ok_or_else(|| bad("layer.create", format!("missing `op` ({OPS})")))?;
@@ -19,6 +22,69 @@ fn create(s: &mut Session, p: &Value) -> Result<Value> {
    let time = s.time();
    let mut created = vec![];
    let mut skipped = vec![];
+    // All the selected models in one edit: one undo (or redo) removes (or restores) every
+    // instance at once, as one command in the History panel.
+    if op == "instance3d" {
+        // After Effects' Create 3D Layer Instance (Layer ▸ Create): 3D model layers take
+        // no masks or effects, so a comp-sized solid goes at the top of the layer stack
+        // with a 3D Layer Instance effect referencing the model — a 2D copy of its render,
+        // through the comp's camera, that 2D effects can be applied to. The model is switched
+        // off, as After Effects does (back on to keep its shadow).
+        let comp = s.project.comp(cid).ok_or(EngineError::NoComp)?.clone();
+        let mut eligible = vec![];
+        for lid in &lids {
+            match comp.layer(*lid) {
+                Some(src) if src.source.is_model() => eligible.push((*lid, src.clone())),
+                Some(src) => skipped.push(format!("{}: not a 3D model layer", src.name)),
+                None => {}
+            }
+        }
+        if !eligible.is_empty() {
+            let ids = s.edit("Create 3D Layer Instance", None, |proj, st| {
+                let mut ids = vec![];
+                for (lid, src) in &eligible {
+                    let name = proj.comp(cid).ok_or(EngineError::NoComp)?.unique_layer_name(&format!("{} Instance", src.name));
+                    let folder = proj.folder_named("Solids").unwrap_or_else(|| proj.add_item("Solids", Label::Yellow, None, ItemKind::Folder));
+                    let sid = proj.add_item(
+                        &name,
+                        src.label,
+                        Some(folder),
+                        ItemKind::Solid(Solid { color: [1.0, 1.0, 1.0], width: comp.width, height: comp.height, pixel_aspect: 1.0 }),
+                    );
+                    let mut l = build::layer(proj, &comp, &name, LayerSource::Solid { item: sid }, (comp.width, comp.height), None);
+                    // A soloed source keeps its Solo switch with video off, and any_solo hides
+                    // the non-soloed copy: the copy takes the Solo over to stay visible.
+                    l.switches.solo = src.switches.solo;
+                    // A 3D Layer Instance effect referencing the 3D layer: the solid shows its
+                    // render (the 2D copy).
+                    let fx = effectcraft_effects::find("ec.3d.instance3d").ok_or_else(|| bad("layer.create", "the 3D Layer Instance effect is missing"))?;
+                    let mut g = effectcraft_effects::instantiate(fx, &mut Ids(&mut proj.next_id), fx.name, [comp.width as f64, comp.height as f64]);
+                    if let Some(pr) = g.get_mut("layer") {
+                        pr.value = KV::Layer(Some(lid.0));
+                    }
+                    if let Some(fxg) = l.props.sub_mut("effects") {
+                        fxg.children.push(g.into());
+                    }
+                    // The model is switched off (After Effects turns the referenced layer off);
+                    // the copies go at the top of the stack, selected.
+                    let c = proj.comp_mut(cid).ok_or(EngineError::NoComp)?;
+                    if let Some(m) = c.layers.iter_mut().find(|x| x.id == *lid) {
+                        m.switches.video = false;
+                    }
+                    let id = l.id;
+                    c.layers.insert(0, l);
+                    ids.push(id);
+                }
+                st.selected_layers = ids.clone();
+                Ok(ids)
+            })?;
+            created.extend(ids.iter().map(|i| i.0));
+        }
+        if created.is_empty() && !skipped.is_empty() {
+            return Err(bad("layer.create", skipped.join("; ")));
+        }
+        return Ok(json!({"layers": created, "skipped": skipped}));
+    }
    for lid in lids {
        let comp = s.project.comp(cid).ok_or(EngineError::NoComp)?.clone();
        let Some(src) = comp.layer(lid).cloned() else { continue };
@@ -198,5 +264,5 @@ fn insert_above(
 }

 pub fn specs() -> Vec<CommandSpec> {
-    vec![cmd!("layer.create", "Create", [], None, "{op: editableText|shapesFromText|masksFromText|shapesFromVector, layers?}", has_layers, create)]
+    vec![cmd!("layer.create", "Create", [], None, "{op: editableText|shapesFromText|masksFromText|shapesFromVector|instance3d, layers?}", has_layers, create)]
 }
@@ -74,9 +74,9 @@ fn select_all(s: &mut Session, _: &Value) -> Result<Value> {
    Ok(json!(s.state.selected_layers.len()))
 }
 fn deselect_all(s: &mut Session, _: &Value) -> Result<Value> {
-    // A deselected layer never keeps an open text edit: commit the edit first, exactly as
-    // `text.endEdit` (an empty Type-tool layer included), so every route — menu, shortcut,
-    // script, MCP — leaves one final state.
+    // A deselected layer never keeps an open text edit: commit it first, exactly as `text.endEdit`,
+    // so every route — menu, shortcut, script, MCP — leaves one final state. An empty Type-tool
+    // layer survives, as it does in After Effects.
    super::text_edit::end_edit(s, &Value::Null)?;
    s.state.selected_layers.clear();
    s.state.selected_props.clear();
@@ -90,7 +90,7 @@ fn deselect_all(s: &mut Session, _: &Value) -> Result<Value> {
 fn relink_copies(comp: &mut Comp, map: &[(LayerId, LayerId)]) {
    let present: Vec<LayerId> = comp.layers.iter().map(|l| l.id).collect();
    let link = |id: LayerId| map.iter().find(|(o, _)| *o == id).map(|(_, c)| *c).or(present.contains(&id).then_some(id));
-    for l in comp.layers.iter_mut().filter(|l| map.iter().any(|(_, c)| *c == l.id)) {
+    for l in comp.layers.iter_mut_where(|l| map.iter().any(|(_, c)| *c == l.id)) {
        l.parent = l.parent.and_then(link);
        l.track_matte = l.track_matte.and_then(|m| link(m.layer).map(|layer| TrackMatte { layer, ..m }));
    }
@@ -133,12 +133,11 @@ fn duplicate(s: &mut Session, p: &Value) -> Result<Value> {
            return super::prop_groups::duplicate_contents(s, &items);
        }
    }
-    // A deselected layer never keeps an open text edit: the copies take the selection, so commit
-    // an open edit first, exactly as `text.endEdit` (typed text kept, an empty Type-tool layer
-    // discarded) and as Deselect All does — one call on the command path so every route (menu,
-    // shortcut, palette, MCP, script) ends the edit and leaves the same final state. Unnamed, the
-    // target is the edited layer even when an engine route selected another one meanwhile; it is
-    // read before the commit, which may discard an empty Type-tool layer and leave nothing to copy.
+    // A deselected layer never keeps an open text edit (#2226): the copies take the selection, so
+    // commit an open edit first, exactly as `text.endEdit` and Deselect All do — one call on the
+    // command path so every route (menu, shortcut, palette, MCP, script) ends the edit and leaves
+    // the same final state. Unnamed, the target is the edited layer even when an engine route
+    // selected another one meanwhile.
    let edited = s.state.text_edit.as_ref().map(|e| e.layer);
    super::text_edit::end_edit(s, &Value::Null)?;
    let (cid, ids) = match edited {
@@ -288,6 +287,7 @@ fn clear_clipboards(s: &mut Session) {
    s.state.contents_clipboard.clear();
    s.state.link_clipboard = None;
    s.state.value_clipboard.clear();
+    s.state.keyframe_text = None;
    s.state.clip_is_keys = false;
 }

@@ -354,10 +354,12 @@ fn copy_properties(s: &mut Session) -> Result<Option<Value>> {
    }
    let mut keys = s.state.selected_keys.clone();
    let mut values = vec![];
+    let mut statics = vec![];
    for (lid, uid) in &leaves {
        let Some(l) = comp.layer(*lid) else { continue };
        let Some(pr) = l.props.find(*uid) else { continue };
        if pr.keys.is_empty() {
+            statics.push((*lid, *uid));
            if let Some(path) = l.props.match_path_of(*uid)
                && !values.iter().any(|(p, _)| *p == path)
            {
@@ -367,6 +369,7 @@ fn copy_properties(s: &mut Session) -> Result<Option<Value>> {
            keys.extend(pr.keys.iter().map(|k| KeyRef { layer: *lid, prop: *uid, time: k.time }));
        }
    }
+    let text = crate::keyframe_text::text(&s.project, comp, &keys, &statics);
    clear_clipboards(s);
    let mut n = 0;
    if !keys.is_empty() {
@@ -375,6 +378,7 @@ fn copy_properties(s: &mut Session) -> Result<Option<Value>> {
        s.state.selected_keys = selected;
        n = r?.as_u64().unwrap_or(0);
    }
+    s.state.keyframe_text = text;
    let v = values.len();
    s.state.value_clipboard = values;
    // Keys alone answer as `keys.copy` does (their count).
@@ -700,7 +704,7 @@ fn label(s: &mut Session, p: &Value) -> Result<Value> {
            }
        }
        if let Some(comp) = proj.comp_mut(cid) {
-            for l in comp.layers.iter_mut().filter(|l| ids.contains(&l.id)) {
+            for l in comp.layers.iter_mut_where(|l| ids.contains(&l.id)) {
                l.label = lab;
            }
        }
@@ -136,7 +136,16 @@ fn warning(s: &mut Session, p: &Value) -> Result<Value> {
    let layer = comp.layer(lid).ok_or(EngineError::NoComp)?;
    let g = layer.effects().and_then(|fx| fx.groups().find(|g| g.uid == uid)).ok_or_else(|| bad(cmd, "no such effect"))?;
    let t = super::time_p(s, p, Some(comp));
-    let ctx = effectcraft_render::EvalCtx { project: &s.project, comp_id: cid, comp, time: t, expr: s.expr.as_deref(), footage: None };
+    let ctx = effectcraft_render::EvalCtx {
+        project: &s.project,
+        comp_id: cid,
+        comp,
+        time: t,
+        expr: s.expr.as_deref(),
+        footage: None,
+        property_overrides: &[],
+        media_overrides: &[],
+    };
    Ok(json!({"effect": uid, "warning": effectcraft_effects::warning(g, &mut |pr| ctx.value(layer, pr))}))
 }

@@ -160,7 +169,16 @@ fn pick_color(s: &mut Session, p: &Value) -> Result<Value> {
    .filter(|pr| pr.ui == effectcraft_project::ParamUi::Color)
    .ok_or_else(|| bad(cmd, "not a colour parameter of this effect"))?;
    let t = super::time_p(s, p, Some(comp));
-    let ctx = effectcraft_render::EvalCtx { project: &s.project, comp_id: cid, comp, time: t, expr: s.expr.as_deref(), footage: None };
+    let ctx = effectcraft_render::EvalCtx {
+        project: &s.project,
+        comp_id: cid,
+        comp,
+        time: t,
+        expr: s.expr.as_deref(),
+        footage: None,
+        property_overrides: &[],
+        media_overrides: &[],
+    };
    let mut r = effectcraft_render::Renderer::new(&s.project, &*s.footage, effectcraft_render::RenderOpts::default());
    r.expr = s.expr.as_deref();
    r.cache = Some(&s.layer_cache);
@@ -288,7 +306,16 @@ impl CryptoProbe {
            let comp = r.project.comp(cid).ok_or("no composition")?;
            let layer = comp.layer(lid).ok_or("no such layer")?;
            let g = layer.effects().and_then(|fx| fx.groups().nth(pos)).ok_or("no such effect")?;
-            let ctx = effectcraft_render::EvalCtx { project: r.project, comp_id: cid, comp, time, expr: r.expr, footage: None };
+            let ctx = effectcraft_render::EvalCtx {
+                project: r.project,
+                comp_id: cid,
+                comp,
+                time,
+                expr: r.expr,
+                footage: None,
+                property_overrides: &[],
+                media_overrides: &[],
+            };
            let params = effectcraft_effects::flatten_params(g, &mut |pr| ctx.value(layer, pr));
            let want = effectcraft_effects::CRYPTO_LAYERS.get(params.e("layer") as usize).copied().unwrap_or("CryptoAsset");
            let aux = r.layer_aux(&ctx, layer).ok_or(NO_CRYPTO)?;
@@ -351,7 +378,16 @@ fn probe_key<'a>(s: &'a Session, p: &Value, cmd: &str) -> Result<(ProbeKey, Tick
    let g = fx.groups().nth(pos).ok_or_else(|| bad(cmd, "no such effect"))?;
    let prop = g.prop("selection").filter(|_| g.match_id == "ec.3d.cryptomatte").ok_or_else(|| bad(cmd, "not a Cryptomatte effect"))?;
    let time = super::time_p(s, p, Some(comp));
-    let ctx = effectcraft_render::EvalCtx { project: &s.project, comp_id: cid, comp, time, expr: s.expr.as_deref(), footage: None };
+    let ctx = effectcraft_render::EvalCtx {
+        project: &s.project,
+        comp_id: cid,
+        comp,
+        time,
+        expr: s.expr.as_deref(),
+        footage: None,
+        property_overrides: &[],
+        media_overrides: &[],
+    };
    let frame = probe_frame(&ctx, layer, pos);
    let o = s.render_opts(Default::default());
    let prefs = (o.nested_switches, o.draft_shadows);
@@ -503,7 +539,16 @@ fn crypto_hit(s: &Session, p: &Value, cmd: &str) -> Result<Hit> {
    let Some(hash) = b.aux.index_at(ax, ay).and_then(|i| b.aux.crypto_id_at(&b.layer, i)) else { return Ok(Hit::Nothing) };
    let (cid, lid, ..) = key.at;
    let comp = s.project.comp(cid).ok_or(EngineError::NoComp)?;
-    let ctx = effectcraft_render::EvalCtx { project: &s.project, comp_id: cid, comp, time, expr: s.expr.as_deref(), footage: None };
+    let ctx = effectcraft_render::EvalCtx {
+        project: &s.project,
+        comp_id: cid,
+        comp,
+        time,
+        expr: s.expr.as_deref(),
+        footage: None,
+        property_overrides: &[],
+        media_overrides: &[],
+    };
    let selection = effectcraft_effects::flatten_params(g, &mut |pr| ctx.value(layer, pr)).s("selection").to_string();
    let driven = prop.expr.as_ref().is_some_and(|e| e.enabled);
    let (aux, layer_name) = (b.aux.clone(), b.layer.clone());
@@ -700,7 +745,7 @@ fn effects_p(s: &Session, p: &Value, cmd: &str) -> Result<Vec<(LayerId, Uid)>> {
    Ok(sel)
 }

-fn effect_time_error(cmd: &str) -> EngineError {
+pub(crate) fn effect_time_error(cmd: &str) -> EngineError {
    bad(cmd, "an effect keyframe converts outside the supported time range")
 }

@@ -736,7 +781,7 @@ fn effect_time(layer: &Layer, time: Tick, to_comp: bool, cmd: &str) -> Result<Ti

 /// Change the key time coordinate system throughout an effect, including nested controls.
 /// Ease speeds are per second in that coordinate system; reversed time swaps the key sides.
-fn retime_effect(group: &mut PropGroup, scale: f64, cmd: &str, mut time: impl FnMut(Tick) -> Result<Tick>) -> Result<()> {
+pub(crate) fn retime_effect(group: &mut PropGroup, scale: f64, cmd: &str, mut time: impl FnMut(Tick) -> Result<Tick>) -> Result<()> {
    let mut result = Ok(());
    group.walk_mut(&mut |pr| {
        if result.is_err() {
@@ -804,6 +849,7 @@ fn copy(s: &mut Session, p: &Value) -> Result<Value> {
    }
    s.state.clipboard.clear();
    s.state.key_clipboard.clear();
+    s.state.keyframe_text = None;
    s.state.contents_clipboard.clear();
    s.state.link_clipboard = None;
    s.state.clip_is_keys = false;
@@ -954,8 +1000,7 @@ fn list(_: &mut Session, p: &Value) -> Result<Value> {
                let mut out = json!({"id": p.id, "name": p.name, "type": p.default.kind_name(), "default": p.default.to_json()});
                match &p.ui {
                    effectcraft_project::ParamUi::Popup { options } => {
-                        // Engine/MCP popup values are zero-based; JSX exposes one-based values.
-                        out["options"] = json!(options.iter().enumerate().map(|(value, label)| json!({"value": value, "label": label})).collect::<Vec<_>>());
+                        out["options"] = super::popup_options(options);
                    }
                    effectcraft_project::ParamUi::Slider { min, max, slider_min, slider_max, decimals } => {
                        out["min"] = json!(min);
@@ -163,6 +163,8 @@ pub fn language_menu() -> Vec<(&'static str, Vec<(&'static str, &'static str)>)>
                ("easeIn(t, tMin, tMax, value1, value2)", "easeIn(t, tMin, tMax, value1, value2)"),
                ("easeOut(t, value1, value2)", "easeOut(t, value1, value2)"),
                ("easeOut(t, tMin, tMax, value1, value2)", "easeOut(t, tMin, tMax, value1, value2)"),
+                ("bezier(t, value1, value2, [x1, y1, x2, y2])", "bezier(t, value1, value2, [x1, y1, x2, y2])"),
+                ("bezier(t, tMin, tMax, value1, value2, [x1, y1, x2, y2])", "bezier(t, tMin, tMax, value1, value2, [x1, y1, x2, y2])"),
            ],
        ),
        (
@@ -87,7 +87,8 @@ pub(crate) fn open(s: &mut Session, p: &Value) -> Result<Value> {
 /// project opened from an XML copy saves as XML again). Fails, writing nothing, when the project
 /// wouldn't read back.
 pub(crate) fn file_text(s: &Session, path: &str) -> Result<String> {
-    let json = s.project.to_file_json_with_view(&s.saved_view())?;
+    let compact = s.prefs.project.compact_project_files && !crate::xml_project::is_xml_path(path);
+    let json = s.project.to_file_json_with_view(&s.saved_view(), compact)?;
    if crate::xml_project::is_xml_path(path) { crate::xml_project::to_xml(&json).map_err(EngineError::Other) } else { Ok(json) }
 }

@@ -124,7 +125,8 @@ fn revert(s: &mut Session, _: &Value) -> Result<Value> {
 }

 /// File ▸ Import; with `addToComp` (files dropped on the Timeline or the Composition viewer) they
-/// also become layers of the active comp ([`add_to_comp`]).
+/// also become layers of the active comp ([`add_to_comp`]); with `newComp` (the empty viewer's
+/// New Composition From Footage) they become one new composition instead ([`new_comp`]).
 ///
 /// With `background` (files dropped on the window or picked in the Import dialog) the files are
 /// probed on a background thread, so decoding a slow video doesn't freeze the app: the job shows
@@ -174,10 +176,10 @@ fn import_cmd(s: &mut Session, p: &Value) -> Result<Value> {
    Ok(r)
 }

-/// After an import (its result `r`): with `addToComp`, the new items become layers of `target`;
-/// what couldn't be added joins the result's errors.
+/// After an import (its result `r`): with `newComp`, the new items become one new composition;
+/// otherwise with `addToComp`, layers of `target`. What couldn't be added joins the result's errors.
 fn finish_import(s: &mut Session, r: &mut Value, target: Option<ItemId>, p: &Value) {
-    let errors = add_to_comp(s, r, target, p);
+    let errors = if b_p(p, "newComp").unwrap_or(false) { new_comp(s, r) } else { add_to_comp(s, r, target, p) };
    if !errors.is_empty()
        && let Some(e) = r.get_mut("errors").and_then(Value::as_array_mut)
    {
@@ -191,18 +193,7 @@ fn finish_import(s: &mut Session, r: &mut Value, target: Option<ItemId>, p: &Val
 /// Project panel) and the other footage. `target` stays open. Returns what couldn't be added.
 pub(crate) fn add_to_comp(s: &mut Session, r: &Value, target: Option<ItemId>, p: &Value) -> Vec<String> {
    let Some(cid) = target.filter(|_| p.get("addToComp").and_then(Value::as_bool).unwrap_or(false)) else { return vec![] };
-    let ids = |k: &str| r.get(k).and_then(Value::as_array).into_iter().flatten().filter_map(Value::as_u64).collect::<Vec<u64>>();
-    let comps = ids("comps");
-    let in_comps: std::collections::HashSet<u64> = comps
-        .iter()
-        .filter_map(|c| s.project.comp(ItemId(*c)))
-        .flat_map(|c| c.layers.iter())
-        .filter_map(|l| match l.source {
-            LayerSource::Footage { item } | LayerSource::Comp { item } | LayerSource::Solid { item } => Some(item.0),
-            _ => None,
-        })
-        .collect();
-    let add: Vec<u64> = comps.iter().copied().chain(ids("items").into_iter().filter(|i| !in_comps.contains(i))).collect();
+    let add = imported(s, r);
    let mut errors = vec![];
    for (k, item) in add.into_iter().enumerate() {
        let mut params = json!({"comp": cid.0, "item": item, "time": p.get("time"), "position": p.get("position")});
@@ -219,6 +210,55 @@ pub(crate) fn add_to_comp(s: &mut Session, r: &Value, target: Option<ItemId>, p:
    errors
 }

+/// What an import (its result `r`) made that belongs in a comp: the comps of layered files
+/// (their layers' footage, in their precomps too, stays in the Project panel), then the other items,
+/// without those comps again or the files' folders.
+fn imported(s: &Session, r: &Value) -> Vec<u64> {
+    let ids = |k: &str| r.get(k).and_then(Value::as_array).into_iter().flatten().filter_map(Value::as_u64).collect::<Vec<u64>>();
+    let comps = ids("comps");
+    let mut in_comps = std::collections::HashSet::new();
+    let mut todo = comps.clone();
+    while let Some(c) = todo.pop() {
+        for l in s.project.comp(ItemId(c)).into_iter().flat_map(|c| c.layers.iter()) {
+            match l.source {
+                LayerSource::Comp { item } if in_comps.insert(item.0) => todo.push(item.0),
+                LayerSource::Footage { item } | LayerSource::Solid { item } => {
+                    in_comps.insert(item.0);
+                }
+                _ => {}
+            }
+        }
+    }
+    let rest = ids("items").into_iter().filter(|i| !in_comps.contains(i) && !comps.contains(i) && !s.project.item(ItemId(*i)).is_some_and(|it| it.is_folder()));
+    comps.iter().copied().chain(rest).collect()
+}
+
+/// With `newComp`, make one composition of the footage and solids an import (its result `r`)
+/// made, as New Comp from Selection does with `single` (first item on top, its settings). A comp
+/// the import made (a layered file) already is the composition, so it stays out, as does data
+/// footage; none left, no new comp. Returns what went wrong.
+fn new_comp(s: &mut Session, r: &Value) -> Vec<String> {
+    let items: Vec<ItemId> = imported(s, r)
+        .into_iter()
+        .map(ItemId)
+        .filter(|i| {
+            s.project.item(*i).is_some_and(|it| match &it.kind {
+                ItemKind::Footage(f) => f.kind != FootageKind::Data,
+                ItemKind::Solid(_) => true,
+                ItemKind::Comp(_) | ItemKind::Folder => false,
+            })
+        })
+        .collect();
+    if items.is_empty() {
+        return vec![];
+    }
+    s.state.project_selection = items;
+    match s.execute("file.newCompFromSelection", json!({"single": true})) {
+        Ok(_) => vec![],
+        Err(e) => vec![e.to_string()],
+    }
+}
+
 /// File ▸ Import, all in one go (scripts and commands built on it); see [`import_cmd`].
 pub(crate) fn import(s: &mut Session, p: &Value) -> Result<Value> {
    let pending = prepare_import(s, p)?;
@@ -745,7 +785,7 @@ pub fn specs() -> Vec<CommandSpec> {
            "File...",
            ["File", "Import"],
            Some("Cmd+I"),
-            "{paths: [string] (files or folders), sequence?: bool (the Sequence checkbox: true imports numbered stills of one run as one image sequence, one picked file bringing its whole run and several picked files that range; default: a numbered still brings its run, except dropped files (drag), which import as stills as in After Effects; folders' runs import as sequences; false imports stills and a folder's files individually), alphabetical?: bool (Force Alphabetical Order: every image of that type in the folder, by name), frameRate?: fps (image sequences; default Settings ▸ Import ▸ Sequence Footage), importAs?: footage|composition|compositionLayerSizes (Photoshop, PDF, Illustrator and EPS files), layer?: name|index (footage of one Photoshop layer), page?: number from 1 (PDF / Illustrator page), drag?: bool (dropped files: Settings ▸ Import ▸ Default Drag Import As; files import as stills unless sequence), addToComp?: bool (also add them to the active comp, at time?, index?, position? as in layer.addItem), background?: bool (probe the files in a background job, jobs.list / jobs.wait; returns {job})}",
+            "{paths: [string] (files or folders), sequence?: bool (the Sequence checkbox: true imports numbered stills of one run as one image sequence, one picked file bringing its whole run and several picked files that range; default false: picked or dropped files import as stills, as in After Effects; folders' runs import as sequences; false imports stills and a folder's files individually), alphabetical?: bool (Force Alphabetical Order: every image of that type in the folder, by name), frameRate?: fps (image sequences; default Settings ▸ Import ▸ Sequence Footage), importAs?: footage|composition|compositionLayerSizes (Photoshop, PDF, Illustrator and EPS files), layer?: name|index (footage of one Photoshop layer), page?: number from 1 (PDF / Illustrator page), drag?: bool (dropped files: Settings ▸ Import ▸ Default Drag Import As; files import as stills unless sequence), addToComp?: bool (also add them to the active comp, at time?, index?, position? as in layer.addItem), newComp?: bool (make one new composition of the footage and solids imported, as file.newCompFromSelection with single; a layered file imported as a composition is that composition and gets no other; takes precedence over addToComp), background?: bool (probe the files in a background job, jobs.list / jobs.wait; returns {job})}",
            always,
            import_cmd
        ),
@@ -5,7 +5,7 @@
 use std::collections::{BTreeMap, BTreeSet};

 use effectcraft_color::Label;
-use effectcraft_project::{AlphaMode, Comp, Footage, FootageKind, ItemId, ItemKind, LayerSource, Project, Solid, limits};
+use effectcraft_project::{AlphaMode, CineonSettings, CineonUnits, Comp, Footage, FootageKind, ItemId, ItemKind, LayerSource, Project, Solid, limits};
 use effectcraft_time::{FrameRate, Tick};
 use serde_json::{Value, json};

@@ -501,7 +501,7 @@ fn run_script(s: &mut Session, p: &Value) -> Result<Value> {
            }
            _ => return Err(bad("file.runScript", format!("step {}: needs `command`", i + 1))),
        };
-        if id == "file.runScript" || id == "script.run" {
+        if super::scripts::RUNS_SCRIPTS.contains(&id.as_str()) {
            return Err(bad("file.runScript", "scripts can't run scripts"));
        }
        let r = if from_file { s.execute_for_script(&id, params) } else { s.execute(&id, params) };
@@ -536,7 +536,7 @@ fn is_jsxbin(name: &str) -> bool {
 }

 /// A script error becomes a toast and a command error.
-fn report_js(s: &mut Session, name: &str, out: Value) -> Result<Value> {
+pub(crate) fn report_js(s: &mut Session, name: &str, out: Value) -> Result<Value> {
    if let Some(e) = out.get("error").filter(|e| !e.is_null()) {
        let line = e.get("line").and_then(Value::as_u64).map(|l| format!(" (line {l})")).unwrap_or_default();
        let msg = e.get("message").and_then(Value::as_str).unwrap_or("script error");
@@ -552,6 +552,13 @@ pub(crate) fn run_js_named(s: &mut Session, code: &str, name: &str) -> Result<Va
    report_js(s, name, out)
 }

+/// Run the code of the script file at `path` (its `#include`s and `$.fileName` use that path),
+/// reported under its file name `name` (Startup and Shutdown scripts).
+pub(crate) fn run_js_file(s: &mut Session, code: &str, path: &str, name: &str) -> Result<Value> {
+    let out = run_js(s, code, path, false)?;
+    report_js(s, name, out)
+}
+
 /// Run JavaScript through the session's scripting engine.
 fn run_js(s: &mut Session, code: &str, name: &str, console: bool) -> Result<Value> {
    let runner = s.script.ok_or_else(|| EngineError::Other("JavaScript scripting is not available in this build".into()))?;
@@ -594,6 +601,131 @@ pub(crate) struct Interpretation {
    preserve_rgb: Option<bool>,
    /// Start Timecode.
    start: Option<StartTimecode>,
+    /// Cineon Settings (DPX and Cineon footage).
+    cineon: CineonEdit,
+}
+
+/// Interpret Footage ▸ Cineon Settings parsed from command parameters (every field optional).
+#[derive(Clone, Debug, Default)]
+struct CineonEdit {
+    /// Logarithmic Conversion.
+    log: Option<bool>,
+    units: Option<CineonUnits>,
+    /// The units the Converted Black and White Points are given in (`pointUnits`, else `cineonUnits`,
+    /// else the footage's own Units).
+    point_units: Option<CineonUnits>,
+    converted_black: Option<f64>,
+    converted_white: Option<f64>,
+    /// 10 Bit Black and White Points.
+    black: Option<f64>,
+    white: Option<f64>,
+    gamma: Option<f64>,
+    rolloff: Option<f64>,
+}
+
+impl CineonEdit {
+    fn parse(p: &Value, cmd: &str) -> Result<CineonEdit> {
+        let units = |key: &str| -> Result<Option<CineonUnits>> {
+            match str_p(p, key) {
+                None => Ok(None),
+                Some(u) => CineonUnits::parse(u).map(Some).ok_or_else(|| bad(cmd, format!("{key}: 10bit|8bit|float, not `{u}`"))),
+            }
+        };
+        let num = |key: &str, lo: f64, hi: f64| -> Result<Option<f64>> {
+            match p.get(key) {
+                None | Some(Value::Null) => Ok(None),
+                Some(v) => v
+                    .as_f64()
+                    .filter(|x| x.is_finite() && (lo..=hi).contains(x))
+                    .map(Some)
+                    .ok_or_else(|| bad(cmd, format!("{key}: a number from {lo} to {hi}"))),
+            }
+        };
+        let units_now = units("cineonUnits")?;
+        Ok(CineonEdit {
+            log: b_p(p, "logConversion"),
+            units: units_now,
+            point_units: units("pointUnits")?.or(units_now),
+            // Range-checked once their units are known (`settings_for`).
+            converted_black: num("convertedBlack", f64::MIN, f64::MAX)?,
+            converted_white: num("convertedWhite", f64::MIN, f64::MAX)?,
+            black: num("tenBitBlack", 0.0, 1023.0)?,
+            white: num("tenBitWhite", 0.0, 1023.0)?,
+            gamma: num("currentGamma", 0.1, 10.0)?,
+            rolloff: num("highlightRolloff", 0.0, 100.0)?,
+        })
+    }
+
+    fn is_empty(&self) -> bool {
+        self.log.is_none()
+            && self.units.is_none()
+            && self.converted_black.is_none()
+            && self.converted_white.is_none()
+            && self.black.is_none()
+            && self.white.is_none()
+            && self.gamma.is_none()
+            && self.rolloff.is_none()
+    }
+
+    /// Footage `f`'s Cineon Settings after this edit; `None` when nothing changes them (no Cineon
+    /// parameters, or `f` is not a DPX or Cineon file).
+    fn settings_for(&self, f: &Footage, cmd: &str) -> Result<Option<CineonSettings>> {
+        if self.is_empty() || !f.is_cineon_file() {
+            return Ok(None);
+        }
+        let mut c = f.cineon;
+        let units = self.point_units.unwrap_or(c.units);
+        let point = |v: f64| -> Result<f32> {
+            let ten = units.to_ten_bit(v);
+            let max = units.from_ten_bit(f64::from(CineonSettings::MAX));
+            if (0.0..=f64::from(CineonSettings::MAX)).contains(&ten) {
+                Ok(ten as f32)
+            } else {
+                Err(bad(cmd, format!("converted points: 0 to {max} in {} units", units.label())))
+            }
+        };
+        if let Some(v) = self.converted_black {
+            c.converted_black = point(v)?;
+        }
+        if let Some(v) = self.converted_white {
+            c.converted_white = point(v)?;
+        }
+        if let Some(v) = self.log {
+            c.log_conversion = v;
+        }
+        if let Some(u) = self.units {
+            c.units = u;
+        }
+        if let Some(v) = self.black {
+            c.black = v as f32;
+        }
+        if let Some(v) = self.white {
+            c.white = v as f32;
+        }
+        if let Some(v) = self.gamma {
+            c.gamma = v as f32;
+        }
+        if let Some(v) = self.rolloff {
+            c.rolloff = v as f32;
+        }
+        if c.black >= c.white {
+            return Err(bad(cmd, "the 10 Bit Black Point must be below the 10 Bit White Point"));
+        }
+        Ok(Some(c))
+    }
+}
+
+/// Footage `f`'s Cineon Settings as commands report them (`null` for files they don't apply to).
+fn cineon_json(f: &Footage) -> Value {
+    if !f.is_cineon_file() {
+        return Value::Null;
+    }
+    let c = &f.cineon;
+    json!({
+        "logConversion": c.log_conversion, "units": c.units.id(),
+        "convertedBlack": c.units.from_ten_bit(f64::from(c.converted_black)), "convertedWhite": c.units.from_ten_bit(f64::from(c.converted_white)),
+        "tenBitBlack": c.black, "tenBitWhite": c.white, "currentGamma": c.gamma, "highlightRolloff": c.rolloff,
+    })
 }

 /// Interpret Footage ▸ Start Timecode.
@@ -687,9 +819,23 @@ impl Interpretation {
                v.as_f64().filter(|x| x.is_finite() && (0.0..=StartTimecode::MAX as f64).contains(x)).map(|x| x.round() as i64).ok_or_else(start_err)?,
            )),
        };
+        it.cineon = CineonEdit::parse(p, cmd)?;
        Ok(it)
    }

+    /// Check the Cineon Settings this interpretation gives each of `footage`: an error names a
+    /// value out of range, or Cineon parameters when none of the footage is DPX or Cineon.
+    pub(crate) fn check<'a>(&self, footage: impl IntoIterator<Item = &'a Footage>, cmd: &str) -> Result<()> {
+        if self.cineon.is_empty() {
+            return Ok(());
+        }
+        let mut any = false;
+        for f in footage {
+            any |= self.cineon.settings_for(f, cmd)?.is_some();
+        }
+        if any { Ok(()) } else { Err(bad(cmd, "Cineon Settings apply to DPX and Cineon footage only")) }
+    }
+
    pub(crate) fn apply(&self, f: &mut Footage, guessed: Option<(AlphaMode, [f32; 3])>) {
        let before = f.frame_rate;
        self.apply_settings(f, guessed);
@@ -749,6 +895,10 @@ impl Interpretation {
        if let Some(v) = self.preserve_rgb {
            f.preserve_rgb = v;
        }
+        // Checked before the edit (`Interpretation::check`).
+        if let Ok(Some(c)) = self.cineon.settings_for(f, "file.interpretFootage") {
+            f.cineon = c;
+        }
        // After the frame rate: timecode is read at the footage's rate.
        if let Some(start) = self.start.as_ref().and_then(|t| t.frame(f.frame_rate)) {
            f.start_timecode = start;
@@ -795,6 +945,11 @@ fn interpret(s: &mut Session, p: &Value) -> Result<Value> {
        return Err(bad("file.interpretFootage", "select footage"));
    }
    let it = Interpretation::parse(p, "file.interpretFootage")?;
+    let footage = items.iter().filter_map(|i| match s.project.item(*i).map(|x| &x.kind) {
+        Some(ItemKind::Footage(f)) => Some(f),
+        _ => None,
+    });
+    it.check(footage, "file.interpretFootage")?;
    let guesses: Vec<Option<(AlphaMode, [f32; 3])>> = items
        .iter()
        .map(|i| match (it.guess, s.project.item(*i).map(|x| &x.kind)) {
@@ -830,7 +985,7 @@ fn interpret(s: &mut Session, p: &Value) -> Result<Value> {
                "item": i.0, "alpha": format!("{:?}", f.alpha), "matteColor": f.premul_color, "invertAlpha": f.invert_alpha,
                "fields": f.fields.label(), "pixelAspect": f.pixel_aspect, "loop": f.loop_count, "frameRate": f.frame_rate.as_f64(),
                "linearLight": f.linear_light, "preserveRgb": f.preserve_rgb, "startTimecode": f.timecode(0), "overrideStart": f.start_timecode.is_some(),
-                "frames": f.sequence_frames(),
+                "frames": f.sequence_frames(), "cineon": cineon_json(f),
            })),
            _ => None,
        })
@@ -861,6 +1016,9 @@ fn apply_interpretation(s: &mut Session, p: &Value) -> Result<Value> {
                f.linear_light = src.linear_light;
                f.preserve_rgb = src.preserve_rgb;
                f.color_profile = src.color_profile;
+                if f.is_cineon_file() && src.is_cineon_file() {
+                    f.cineon = src.cineon;
+                }
                if src.native_rate.is_some() {
                    if f.native_rate.is_none() {
                        f.native_rate = Some(f.frame_rate);
@@ -878,10 +1036,34 @@ fn replace_footage(s: &mut Session, p: &Value) -> Result<Value> {
    let path = str_p(p, "path").ok_or_else(|| bad("file.replaceFootage", "missing `path`"))?.to_string();
    let item = *items_p(s, p).first().ok_or_else(|| bad("file.replaceFootage", "select footage"))?;
    let importer = s.importer.clone().ok_or_else(|| EngineError::Other("media import is not available in this build".into()))?;
-    // A numbered still brings its image sequence, as on import (`sequence: false` for one frame).
-    let opts = SequenceOptions::from_params(p);
+    // Replacing a still keeps it a still; replacing a sequence keeps bringing the new file's run.
+    // `sequence`/`alphabetical` override that (#2073).
+    let previous = match s.project.item(item).map(|it| &it.kind) {
+        Some(ItemKind::Footage(f)) if f.kind == FootageKind::Sequence => (true, true, f.alphabetical),
+        _ => (false, false, false),
+    };
+    // Only `sequence` decides whether the item keeps its kind; `alphabetical` is a sequence
+    // modifier, not a request to make one.
+    let inherited = b_p(p, "sequence").is_none();
+    let mut opts = SequenceOptions::from_params(p);
+    if inherited {
+        (opts.sequence, opts.folders) = (previous.0, previous.1);
+        if previous.0 && b_p(p, "alphabetical").is_none() {
+            opts.alphabetical = previous.2;
+        }
+    }
    let src = crate::sequence::source_of(s.services.as_ref(), &path, opts);
-    let f = crate::sequence::probe(importer.as_ref(), &src, s.sequence_rate()).map_err(|e| EngineError::Other(format!("{path}: {e}")))?;
+    let mut f = crate::sequence::probe(importer.as_ref(), &src, s.sequence_rate()).map_err(|e| EngineError::Other(format!("{path}: {e}")))?;
+    // A single-file source comes back as a still; an inherited sequence kind keeps it a
+    // one-frame sequence, so a later default replacement still brings numbered runs (#2073).
+    if inherited && previous.0 && matches!(src, crate::sequence::Source::File(_)) && f.kind == FootageKind::Still {
+        f.kind = FootageKind::Sequence;
+        f.sequence = vec![f.path.clone()];
+        f.alphabetical = opts.alphabetical;
+        f.frame_rate = s.sequence_rate();
+        f.native_rate = None;
+        f.sync_sequence_duration();
+    }
    let name = src.name();
    // Replacing a missing file relinks the other missing files that moved with it (as After Effects
    // does when you locate one).
@@ -1066,7 +1248,7 @@ pub fn specs() -> Vec<CommandSpec> {
            "Main...",
            ["File", "Interpret Footage"],
            Some("Cmd+Alt+G"),
-            "{items?, frameRate?: fps|\"file\", alpha?: straight|premultiplied|ignore|guess, guessAlpha?, matteColor?, invertAlpha?, loop?, pixelAspect?, fields?: off|upper|lower, colorProfile?: srgb|rec709|rec2020|p3|auto, linearLight?, preserveRgb? (the file's values unconverted), overrideStart?: bool (false: Use Source File Timecode), startTimecode?: timecode|frame (Override Start)}",
+            "{items?|item?, frameRate?: fps|\"file\", alpha?: straight|premultiplied|ignore|guess, guessAlpha?, matteColor?|premulColor?, invertAlpha?, loop?, pixelAspect?, fields?: off|upper|lower, colorProfile?: srgb|rec709|rec2020|p3|auto, linearLight?, preserveRgb? (the file's values unconverted), overrideStart?: bool (false: Use Source File Timecode), startTimecode?: timecode|frame (Override Start), logConversion? (Cineon Settings of DPX and Cineon files), cineonUnits?: 10bit|8bit|float, convertedBlack?, convertedWhite?, pointUnits?: 10bit|8bit|float (the units of convertedBlack and convertedWhite; default cineonUnits, else the footage's Units), tenBitBlack?, tenBitWhite? (0..1023), currentGamma? (0.1..10), highlightRolloff? (0..100)}",
            has_footage_selection,
            interpret
        ),
@@ -1084,7 +1266,7 @@ pub fn specs() -> Vec<CommandSpec> {
            "Apply Interpretation",
            ["File", "Interpret Footage"],
            Some("Cmd+Alt+V"),
-            "{items?}",
+            "{items?|item?}",
            has_interpretation,
            apply_interpretation
        ),
@@ -1093,7 +1275,7 @@ pub fn specs() -> Vec<CommandSpec> {
            "File...",
            ["File", "Replace Footage"],
            Some("Cmd+H"),
-            "{path, item?, sequence?: bool (default true: a numbered still brings its image sequence), alphabetical?: bool}",
+            "{path, item?, sequence?: bool (a numbered still brings its image sequence; default: the item keeps its kind, so a still stays a still and a sequence stays a sequence), alphabetical?: bool}",
            has_footage_selection,
            replace_footage
        ),
@@ -1115,7 +1297,7 @@ pub fn specs() -> Vec<CommandSpec> {
            has_footage_selection,
            replace_with_solid
        ),
-        cmd!("file.reloadFootage", "Reload Footage", ["File"], Some("Cmd+Alt+L"), "{items?}", has_footage_selection, reload),
+        cmd!("file.reloadFootage", "Reload Footage", ["File"], Some("Cmd+Alt+L"), "{items?|item?}", has_footage_selection, reload),
        cmd!("file.revealInFinder", "Reveal in Finder", ["File"], None, "{item?}", has_footage_selection, reveal_in_finder),
    ]
 }
@@ -78,6 +78,12 @@ fn set_to_layer(s: &mut Session, p: &Value) -> Result<Value> {
    let c = "camera.setFocusToLayer";
    let (cid, cam, target) = refs(s, p, c, true)?;
    let d = focus_depth(s, cid, cam, target.ok_or_else(|| bad(c, "no layer"))?).ok_or_else(|| bad(c, "can't evaluate the layers"))?;
+    // Only a finite depth can be stored: JSON has no infinity or NaN, so the project could no
+    // longer be saved. Extreme but finite positions can still produce one, and `d <= 0.0` is
+    // false for NaN.
+    if !d.is_finite() {
+        return Err(bad(c, "can't measure the distance to the layer (the camera or layer position is out of range)"));
+    }
    if d <= 0.0 {
        return Err(bad(c, "the layer is behind the camera"));
    }
@@ -56,6 +56,12 @@ pub fn timecode(item: Option<&effectcraft_project::Item>, fr: effectcraft_time::
    }
 }

+/// The frame the Footage panel shows: footage `f` at source time `t`, with its Cineon Settings
+/// applied.
+pub fn frame(s: &Session, item: ItemId, f: &effectcraft_project::Footage, t: Tick) -> Option<std::sync::Arc<effectcraft_raster::Image>> {
+    s.footage.frame(item, f, t).map(|img| effectcraft_render::cineon_frame(img, f))
+}
+
 fn source_time(s: &Session, p: &Value, item: ItemId) -> Option<Tick> {
    let (_, fr) = source_timing(s, item);
    if let Some(t) = f_p(p, "time") {
@@ -207,10 +213,7 @@ fn info(s: &mut Session, _: &Value) -> Result<Value> {
    let item = s.project.item(v.item);
    let name = item.map(|i| i.name.clone()).unwrap_or_default();
    let frame = fr.frame_at(v.time);
-    let problem = match item.map(|i| &i.kind) {
-        Some(ItemKind::Footage(f)) => s.footage.problem(f),
-        _ => None,
-    };
+    let problem = item.and_then(|i| s.footage.item_problem(i));
    Ok(
        json!({"item": v.item.0, "name": name, "time": v.time.seconds(), "frame": frame, "timecode": timecode(item, fr, frame), "in": v.in_point.map(|t| t.seconds()), "out": v.out_point.map(|t| t.seconds()), "duration": dur.map(|d| d.seconds()), "frameRate": fr.as_f64(), "problem": problem}),
    )
@@ -49,7 +49,7 @@ pub fn specs() -> Vec<CommandSpec> {
            "Text",
            ["Layer", "New"],
            Some("Cmd+Alt+Shift+T"),
-            "{text?, name? (layer name; default the text), position? [x,y], box? [x,y,w,h] (paragraph text, comp space), vertical?, edit? (start editing), font?, style?, size?, fill?, stroke?, applyFill?, applyStroke?, strokeWidth?, tracking?, leading?, baselineShift?, hScale?, vScale?, tsume?, fauxBold?, fauxItalic?, allCaps?, smallCaps?, baseline?, superscript?, subscript?, kerning?, ligatures?, justify?, indentLeft?, indentRight?, indentFirst?, spaceBefore?, spaceAfter?, direction?, composer?, hangingPunctuation?, strokeOverFill?} (attributes as layer.setText)",
+            "{text?, name? (layer name; default the text), position? [x,y], box? [x,y,w,h] (paragraph text, comp space), vertical?, edit? (start editing), font?, style?, size?, fill?, stroke?, applyFill?, applyStroke?, strokeWidth?, tracking?, leading?, baselineShift?, hScale?, vScale?, tsume?, fauxBold?, fauxItalic?, allCaps?, smallCaps?, baseline?, superscript?, subscript?, kerning?, ligatures?, justify?, indentLeft?, indentRight?, indentFirst?, spaceBefore?, spaceAfter?, direction?, composer?, hangingPunctuation?, strokeOverFill?, lineJoin?} (attributes as layer.setText)",
            has_comp,
            new_text
        ),
@@ -122,7 +122,7 @@ pub fn specs() -> Vec<CommandSpec> {
            "Track Matte",
            [],
            None,
-            "{layer?, matte: layer|null, kind?: alpha|alphaInverted|luma|lumaInverted}",
+            "{layers? | layer?, matte: layer|null, kind?: alpha|alphaInverted|luma|lumaInverted|preserve}",
            has_layers,
            track_matte
        ),
@@ -184,7 +184,7 @@ pub fn specs() -> Vec<CommandSpec> {
            "Add (Shape)",
            [],
            None,
-            "{layer?, kind: group|rect|ellipse|star|polygon|path|fill|stroke|gfill|gstroke|trim|repeater|round|offset|pucker|twist|zigzag|wiggle|merge|frontColor|bevelColor|sideColor|backColor, group?: uid|path} → {uid, path} (frontColor…backColor: the group's Front / Bevel / Side / Back item, which colours that surface of every extruded paint in the group in Advanced 3D)",
+            "{layer?, kind: group|rect|ellipse|star|polygon|path|fill|stroke|gfill|gstroke|trim|repeater|round|offset|pucker|twist|zigzag|wiggle|wiggler|merge|frontColor|bevelColor|sideColor|backColor, group?: uid|path} → {uid, path} (frontColor…backColor: the group's Front / Bevel / Side / Back item, which colours that surface of every extruded paint in the group in Advanced 3D)",
            has_layers,
            add_shape_item
        ),
@@ -193,7 +193,7 @@ pub fn specs() -> Vec<CommandSpec> {
            "Edit Text",
            [],
            None,
-            "{layer?, range?: [start, end] (characters; default all), text?, font?, style?, size?, fill?, stroke?, applyFill?, applyStroke?, strokeWidth?, tracking?, leading?: px|\"auto\", baselineShift? px, hScale? %, vScale? %, tsume? %, fauxBold?, fauxItalic?, allCaps?, smallCaps?, baseline?: normal|superscript|subscript, superscript?, subscript?, kerning?: metrics|optical|number, ligatures?, discretionaryLigatures? (OpenType), contextualAlternates?, stylisticAlternates?, stylisticSets?: [1–20], ss01?, ss02?, ss03?, ss04?, ss05?, ss06?, ss07?, ss08?, ss09?, ss10?, ss11?, ss12?, ss13?, ss14?, ss15?, ss16?, ss17?, ss18?, ss19?, ss20?, swash?, titling?, ordinals?, fractions?, allSmallCaps?, figureStyle?: default|lining|oldStyle, figureWidth?: default|proportional|tabular, figures?, variations?: {tag: value} (variable font axes; null resets), justify?: left|center|right|justifyLeft|justifyCenter|justifyRight|justifyAll, indentLeft?, indentRight?, indentFirst?, spaceBefore?, spaceAfter?, direction?: ltr|rtl, composer?: everyLine|singleLine, hangingPunctuation?, strokeOverFill?, box?: [x,y,w,h]|null (layer space), vertical?}",
+            "{layer?, range?: [start, end] (characters; default all), text?, font?, style?, size?, fill?, stroke?, applyFill?, applyStroke?, strokeWidth?, tracking?, leading?: px|\"auto\", baselineShift? px, hScale? %, vScale? %, tsume? %, fauxBold?, fauxItalic?, allCaps?, smallCaps?, baseline?: normal|superscript|subscript, superscript?, subscript?, kerning?: metrics|optical|number, ligatures?, discretionaryLigatures? (OpenType), contextualAlternates?, stylisticAlternates?, stylisticSets?: [1–20], ss01?, ss02?, ss03?, ss04?, ss05?, ss06?, ss07?, ss08?, ss09?, ss10?, ss11?, ss12?, ss13?, ss14?, ss15?, ss16?, ss17?, ss18?, ss19?, ss20?, swash?, titling?, ordinals?, fractions?, allSmallCaps?, figureStyle?: default|lining|oldStyle, figureWidth?: default|proportional|tabular, figures?, variations?: {tag: value} (variable font axes; null resets), justify?: left|center|right|justifyLeft|justifyCenter|justifyRight|justifyAll, indentLeft?, indentRight?, indentFirst?, spaceBefore?, spaceAfter?, direction?: ltr|rtl, composer?: everyLine|singleLine, hangingPunctuation?, strokeOverFill?, lineJoin?: miter|round|bevel, box?: [x,y,w,h]|null (layer space), vertical?}",
            has_layers,
            set_text
        ),
@@ -161,7 +161,7 @@ pub(super) fn text_range_p(p: &Value) -> Option<std::ops::Range<usize>> {
 /// It is left justified unless `justify` is given. The layer is named by `name`, else the first 40
 /// characters of the first text line, else "Text". `edit: true` also opens a new editing
 /// session with anchor `0` and the caret after the text, selecting all initial text so the next
-/// insertion replaces it. The session has `created: true`, so leaving it empty removes the layer.
+/// insertion replaces it. The session has `created: true`; leaving it empty keeps the layer, as After Effects does.
 pub(super) fn new_text(s: &mut Session, p: &Value) -> Result<Value> {
    let cid = comp_id(s, p)?;
    let comp = s.project.comp(cid).ok_or(EngineError::NoComp)?.clone();
@@ -1,4 +1,4 @@
-use super::{Comp, EngineError, ItemId, KV, Layer, LayerId, PropGroup, Result, Session, Tick, Value, b_p, bad, layers_p, resolve_layer};
+use super::{Comp, EngineError, ItemId, KV, Layer, LayerId, PropGroup, Result, Session, Tick, Value, b_p, bad, layers_p, resolve_layer, unlocked};

 /// Re-express a layer in its new parent space without moving its anchor.
 pub(crate) struct ParentFix {
@@ -9,10 +9,20 @@ pub(crate) struct ParentFix {
    rotation: f64,
    /// Multiply Scale.
    scale: [f64; 2],
-    /// 3D AV layers retain their world-space anchor, including Z.
+    /// 3D AV layers retain their world-space anchor, including Z. Cameras and lights also
+    /// re-express their Point of Interest.
    position_3d: Option<effectcraft_geom::Mat4>,
-    /// A uniform relative parent transform can preserve static Orientation and Scale.
-    pose_3d: Option<([f64; 3], f64)>,
+    /// A uniform relative parent transform re-expresses static Orientation and Scale.
+    pose_3d: Option<Pose3d>,
+}
+
+/// A uniform relative parent transform, as it applies to a 3D layer's Orientation and Scale.
+#[derive(Clone, Copy)]
+struct Pose3d {
+    /// Rotation that Orientation is re-expressed under: `Orientation' = correction * Orientation`.
+    correction: effectcraft_geom::Mat4,
+    /// Uniform scale factor, multiplied into Scale (negative for a mirrored parent).
+    factor: f64,
 }

 impl ParentFix {
@@ -22,7 +32,7 @@ impl ParentFix {
        if let Some(m) = self.position_3d {
            // Spatial Position speed measures distance along its path. Its parent-space
            // unit changes even when the child's Orientation cannot be re-expressed.
-            let position_speed = uniform_parent_pose(m, [0.0; 3]).map(|(_, factor)| factor.abs());
+            let position_speed = uniform_rotation(m).map(|(_, factor)| factor.abs());
            let map_position = |v: &KV| {
                let q = m.apply(effectcraft_geom::Vec3::from(v.as_vec3()));
                KV::Vec3([q.x, q.y, q.z])
@@ -44,7 +54,8 @@ impl ParentFix {
                    }
                }
            }
-            if let Some(pr) = tr.get_mut("position") {
+            // Position and a camera's or light's Point of Interest are both points in the parent's space.
+            let map_point = |pr: &mut effectcraft_project::Property| {
                pr.value = map_position(&pr.value);
                for key in &mut pr.keys {
                    key.value = map_position(&key.value);
@@ -64,34 +75,19 @@ impl ParentFix {
                        }
                    }
                }
+            };
+            if let Some(pr) = tr.get_mut("position") {
+                map_point(pr);
            }
-            // Cameras and lights aim with Point of Interest: move it by the same parent-space
-            // change, so a two-node rig keeps its world frame (#1010, #1020).
            if let Some(pr) = tr.get_mut("poi") {
-                pr.value = map_position(&pr.value);
-                for key in &mut pr.keys {
-                    key.value = map_position(&key.value);
-                    for tangent in [&mut key.spatial_in, &mut key.spatial_out] {
-                        let v = m.apply_vec(effectcraft_geom::Vec3::from(*tangent));
-                        *tangent = [v.x, v.y, v.z];
-                    }
-                }
-                if let Some(factor) = position_speed
-                    .filter(|_| pr.spatial)
-                    .filter(|factor| pr.keys.iter().flat_map(|key| key.in_ease.iter().chain(&key.out_ease)).all(|ease| (ease.speed * *factor).is_finite()))
-                {
-                    for key in &mut pr.keys {
-                        for ease in key.in_ease.iter_mut().chain(&mut key.out_ease) {
-                            ease.speed *= factor;
-                        }
-                    }
-                }
+                map_point(pr);
            }
-            if let Some((orientation, factor)) = self.pose_3d {
+            if let Some(pose) = self.pose_3d {
                if let Some(pr) = tr.get_mut("orientation") {
-                    pr.value = KV::Vec3(orientation);
+                    reexpress_orientation(pose.correction, pr);
                }
                if let Some(pr) = tr.get_mut("scale") {
+                    let factor = pose.factor;
                    let scaled = |value: &KV| KV::Vec3(value.as_vec3().map(|v| v * factor));
                    pr.value = scaled(&pr.value);
                    for key in &mut pr.keys {
@@ -154,13 +150,10 @@ impl ParentFix {
    }
 }

-/// A uniform factor commutes with authored axis Rotation and Scale; prepend its orthogonal
-/// rotation to static Orientation using the existing Rz * Ry * Rx order.
-fn uniform_parent_pose(m: effectcraft_geom::Mat4, orientation: [f64; 3]) -> Option<([f64; 3], f64)> {
-    use effectcraft_geom::{Mat4, Vec3, vec3};
-    if !orientation.iter().all(|v| v.is_finite()) {
-        return None;
-    }
+/// The rotation and signed scale factor of a uniform parent transform's linear part (negative for a
+/// mirrored parent). `None` for a non-uniform or degenerate transform.
+fn uniform_rotation(m: effectcraft_geom::Mat4) -> Option<(effectcraft_geom::Mat4, f64)> {
+    use effectcraft_geom::{Mat4, vec3};
    let a = m.0;
    let columns = [vec3(a[0][0], a[1][0], a[2][0]), vec3(a[0][1], a[1][1], a[2][1]), vec3(a[0][2], a[1][2], a[2][2])];
    let magnitude = columns[0].x.hypot(columns[0].y).hypot(columns[0].z);
@@ -179,15 +172,188 @@ fn uniform_parent_pose(m: effectcraft_geom::Mat4, orientation: [f64; 3]) -> Opti
            rotation.0[row][col] = a[row][col] / factor;
        }
    }
-    if (0..3).all(|row| (0..3).all(|col| (rotation.0[row][col] - if row == col { 1.0 } else { 0.0 }).abs() < 1e-12)) {
-        return Some((orientation, factor));
-    }
-    let r = (rotation * Mat4::orientation(Vec3::from(orientation))).0;
+    Some((rotation, factor))
+}
+
+/// The turn (degrees) of a rotation about Z alone, or `None` for any other rotation.
+fn z_only_turn(correction: effectcraft_geom::Mat4) -> Option<f64> {
+    let m = correction.0;
+    let about_z = [m[0][2], m[1][2], m[2][0], m[2][1]].iter().all(|v| v.abs() < 1e-9) && (m[2][2] - 1.0).abs() < 1e-9;
+    about_z.then(|| m[1][0].atan2(m[0][0]).to_degrees())
+}
+
+/// ZYX Euler angles in degrees of a row-major rotation (`Rz * Ry * Rx`), safe at gimbal lock.
+fn euler_zyx(r: [[f64; 4]; 4]) -> [f64; 3] {
    // atan2 rather than asin: near ±90 degrees asin loses precision, while cos(y) stays exact.
    let cy = r[0][0].hypot(r[1][0]);
    let y = (-r[2][0]).atan2(cy);
    let (x, z) = if cy > 1e-9 { (r[2][1].atan2(r[2][2]), r[1][0].atan2(r[0][0])) } else { ((-r[1][2]).atan2(r[1][1]), 0.0) };
-    Some(([x.to_degrees(), y.to_degrees(), z.to_degrees()], factor))
+    [x.to_degrees(), y.to_degrees(), z.to_degrees()]
+}
+
+/// The equivalent ZYX Euler triple nearest `reference`: each axis moved by whole turns, or the
+/// `(x + 180, 180 - y, z + 180)` form when that is nearer.
+fn nearest_euler(euler: [f64; 3], reference: [f64; 3]) -> [f64; 3] {
+    let near = |v: [f64; 3]| -> [f64; 3] { std::array::from_fn(|i| v[i] + ((reference[i] - v[i]) / 360.0).round() * 360.0) };
+    let natural = near(euler);
+    let flipped = near([euler[0] + 180.0, 180.0 - euler[1], euler[2] + 180.0]);
+    let distance = |v: [f64; 3]| v.iter().zip(reference.iter()).map(|(a, b)| (a - b).powi(2)).sum::<f64>();
+    if distance(flipped) < distance(natural) { flipped } else { natural }
+}
+
+/// The Euler Orientation of `correction * Orientation(o)`, in the form nearest `reference`.
+fn reexpress_euler(correction: effectcraft_geom::Mat4, o: [f64; 3], reference: [f64; 3]) -> [f64; 3] {
+    let world = correction * effectcraft_geom::Mat4::orientation(effectcraft_geom::Vec3::from(o));
+    nearest_euler(euler_zyx(world.0), reference)
+}
+
+/// Largest angle (degrees) a baked Orientation may drift from the exact rotation between its keys.
+const BAKE_TOLERANCE_DEGREES: f64 = 0.05;
+/// How many times a segment may be halved while baking, and the most keys a property may end up with.
+const BAKE_MAX_DEPTH: u32 = 10;
+const BAKE_MAX_KEYS: usize = 4096;
+
+/// The angle (degrees) between two rotations.
+fn rotation_angle(a: effectcraft_geom::Mat4, b: effectcraft_geom::Mat4) -> f64 {
+    let trace: f64 = (0..3).flat_map(|i| (0..3).map(move |j| (i, j))).map(|(i, j)| a.0[i][j] * b.0[i][j]).sum();
+    ((trace - 1.0) / 2.0).clamp(-1.0, 1.0).acos().to_degrees()
+}
+
+/// Adds keys between `(ta, ea)` and `(tb, eb)` (already converted) wherever the straight Euler blend
+/// between them drifts from `correction * Orientation(authored)` by more than the tolerance. `out`
+/// never grows past `budget` keys: what the whole property may still add, not what one segment may.
+fn bake_between(
+    correction: effectcraft_geom::Mat4,
+    authored: &effectcraft_project::Property,
+    (ta, ea): (Tick, [f64; 3]),
+    (tb, eb): (Tick, [f64; 3]),
+    depth: u32,
+    budget: usize,
+    out: &mut Vec<effectcraft_keyframe::Keyframe>,
+) {
+    use effectcraft_geom::{Mat4, Vec3};
+    if depth == 0 || tb.0 - ta.0 < 2 || out.len() >= budget {
+        return;
+    }
+    let tm = Tick(ta.0 + (tb.0 - ta.0) / 2);
+    let blend = [(ea[0] + eb[0]) / 2.0, (ea[1] + eb[1]) / 2.0, (ea[2] + eb[2]) / 2.0];
+    let exact = correction * Mat4::orientation(Vec3::from(authored.value_at(tm).as_vec3()));
+    // Symmetric easing crosses the straight blend at its midpoint. Check both sides too before
+    // accepting a segment whose original easing will be replaced with a linear blend.
+    let quarter = (tb.0 - ta.0) / 4;
+    if [Tick(ta.0 + quarter), tm, Tick(tb.0 - quarter)].into_iter().all(|t| {
+        let u = (t.0 - ta.0) as f64 / (tb.0 - ta.0) as f64;
+        let linear = std::array::from_fn(|i| ea[i] + (eb[i] - ea[i]) * u);
+        let target = correction * Mat4::orientation(Vec3::from(authored.value_at(t).as_vec3()));
+        rotation_angle(Mat4::orientation(Vec3::from(linear)), target) <= BAKE_TOLERANCE_DEGREES
+    }) {
+        return;
+    }
+    let em = nearest_euler(euler_zyx(exact.0), blend);
+    bake_between(correction, authored, (ta, ea), (tm, em), depth - 1, budget, out);
+    if out.len() >= budget {
+        return;
+    }
+    out.push(effectcraft_keyframe::Keyframe::new(tm, KV::Vec3(em)));
+    bake_between(correction, authored, (tm, em), (tb, eb), depth - 1, budget, out);
+}
+
+/// Re-expresses Orientation as `correction * Orientation`. A Z-only correction shifts Z exactly in the
+/// value and every key. For any other correction a static value is converted directly; keys are
+/// converted, and keys are added between them wherever the Euler blend between two keys would drift
+/// from the exact rotation (the segments become linear, with the original easing baked in).
+fn reexpress_orientation(correction: effectcraft_geom::Mat4, pr: &mut effectcraft_project::Property) {
+    if let Some(turn) = z_only_turn(correction) {
+        // No turn (an identity correction) leaves every authored value as it is.
+        if turn.abs() <= 1e-12 {
+            return;
+        }
+        let shift = |value: &KV| {
+            let [x, y, z] = value.as_vec3();
+            KV::Vec3([x, y, z + turn])
+        };
+        pr.value = shift(&pr.value);
+        for key in &mut pr.keys {
+            key.value = shift(&key.value);
+        }
+        return;
+    }
+    let value = pr.value.as_vec3();
+    pr.value = KV::Vec3(reexpress_euler(correction, value, value));
+    if pr.keys.is_empty() {
+        return;
+    }
+    let authored = pr.clone();
+    // Each key keeps the authored change from the previous key on top of its converted value.
+    let mut converted: Vec<[f64; 3]> = vec![];
+    let mut prev: Option<([f64; 3], [f64; 3])> = None;
+    for key in &authored.keys {
+        let o = key.value.as_vec3();
+        let reference = match prev {
+            Some((before, after)) => [after[0] + o[0] - before[0], after[1] + o[1] - before[1], after[2] + o[2] - before[2]],
+            None => o,
+        };
+        let n = reexpress_euler(correction, o, reference);
+        converted.push(n);
+        prev = Some((o, n));
+    }
+    use effectcraft_keyframe::Interp;
+    let mut keys: Vec<effectcraft_keyframe::Keyframe> = vec![];
+    let mut after_baked_segment = false;
+    for (i, key) in authored.keys.iter().enumerate() {
+        let mut k = key.clone();
+        k.value = KV::Vec3(converted[i]);
+        if after_baked_segment {
+            k.in_interp = Interp::Linear;
+            k.in_ease.clear();
+            k.auto_bezier = false;
+            k.continuous = false;
+        }
+        after_baked_segment = false;
+        let segment = authored.keys.get(i + 1).filter(|_| key.out_interp != Interp::Hold);
+        let mut between = vec![];
+        if let Some(next) = segment {
+            // What the whole property may still add: the keys it will have already (the ones written
+            // and the authored ones still to come) count against the cap.
+            let budget = BAKE_MAX_KEYS.saturating_sub(keys.len() + authored.keys.len() - i);
+            bake_between(correction, &authored, (key.time, converted[i]), (next.time, converted[i + 1]), BAKE_MAX_DEPTH, budget, &mut between);
+            // With the cap reached the segment can't be checked or subdivided: it keeps its authored easing between
+            // the converted keys, rather than becoming a straight blend that was never checked against the original.
+            if between.len() >= budget {
+                between.clear();
+            // An eased segment, or one that gained keys, becomes a run of straight blends.
+            } else if !between.is_empty() || key.out_interp != Interp::Linear || next.in_interp != Interp::Linear {
+                k.out_interp = Interp::Linear;
+                k.out_ease.clear();
+                k.auto_bezier = false;
+                k.continuous = false;
+                after_baked_segment = true;
+            }
+        }
+        keys.push(k);
+        keys.extend(between);
+    }
+    pr.keys = keys;
+}
+
+/// Correction for a two-node rig's Orientation: after a uniform parent change its aim is
+/// `rotation * aim`, so the roll is re-expressed against that aim. `None` for a degenerate aim.
+fn aim_correction(rotation: effectcraft_geom::Mat4, aim: [f64; 3]) -> Option<effectcraft_geom::Mat4> {
+    use effectcraft_geom::vec3;
+    use effectcraft_render::three_d::camera::basis_rotation;
+    let [x, y, z] = aim;
+    let length = (x * x + y * y + z * z).sqrt();
+    if !length.is_finite() || length <= 1e-9 {
+        return None;
+    }
+    let dir = vec3(x / length, y / length, z / length);
+    let turned = rotation.apply_vec(dir);
+    // A view along the up axis has no roll to keep, and its basis is undefined.
+    if 1.0 - dir.y * dir.y < 1e-12 || 1.0 - turned.y * turned.y < 1e-12 {
+        return None;
+    }
+    let up = vec3(0.0, 1.0, 0.0);
+    Some(basis_rotation(turned, up).transpose() * rotation * basis_rotation(dir, up))
 }

 /// A parent change retains 2D transforms and the world-space anchor of 3D layers (Position,
@@ -196,8 +362,16 @@ fn uniform_parent_pose(m: effectcraft_geom::Mat4, orientation: [f64; 3]) -> Opti
 /// time.
 pub(crate) fn parent_fixes(s: &Session, cid: ItemId, ids: &[LayerId], parent: Option<LayerId>) -> Vec<ParentFix> {
    let Some(comp) = s.project.comp(cid) else { return vec![] };
-    let ectx =
-        effectcraft_render::EvalCtx { project: &s.project, comp_id: cid, comp, time: s.time(), expr: s.expr.as_deref(), footage: Some(s.footage.as_ref()) };
+    let ectx = effectcraft_render::EvalCtx {
+        project: &s.project,
+        comp_id: cid,
+        comp,
+        time: s.time(),
+        expr: s.expr.as_deref(),
+        footage: Some(s.footage.as_ref()),
+        property_overrides: &[],
+        media_overrides: &[],
+    };
    let space = |id: Option<LayerId>| -> effectcraft_geom::Mat3 {
        id.and_then(|i| comp.layer(i)).filter(|l| !l.is_3d()).map(|l| ectx.layer_to_comp(l).0).unwrap_or(effectcraft_geom::Mat3::IDENTITY)
    };
@@ -235,31 +409,58 @@ pub(crate) fn parent_fixes(s: &Session, cid: ItemId, ids: &[LayerId], parent: Op
        })
    };
    if let Some(inv) = space_3d(parent).inverse().filter(|m| m.0.iter().flatten().all(|v| v.is_finite())) {
-        // Cameras and lights compensate like 3D layers (Position, and Point of Interest for
-        // two-node rigs), so parenting keeps the world frame (#1010, #1020). They have no
-        // Scale, so `pose_3d` below stays `None` and Orientation is kept as authored.
        for layer in comp.layers.iter().filter(|l| ids.contains(&l.id) && l.is_3d() && l.parent != parent) {
            let m = inv * space_3d(layer.parent);
+            // A one-node camera or light has no Scale to carry a mirror, and its frame (forward and
+            // down) would come out reversed: compensate none of it, so Position and Orientation stay
+            // as authored instead of half-following the parent.
+            let rig = layer.is_camera() || layer.is_light();
+            if rig && !effectcraft_render::three_d::camera::is_two_node(layer) && uniform_rotation(m).is_some_and(|(_, factor)| factor <= 0.0) {
+                continue;
+            }
            if m.0.iter().flatten().all(|v| v.is_finite()) {
                let pose_3d = layer.transform().and_then(|tr| {
                    let orientation = tr.get("orientation")?;
-                    let scale = tr.get("scale")?;
-                    // Animated Euler Orientation and auto-orient cannot be re-expressed by
-                    // prepending a constant Euler value. Expression-driven values stay authored.
-                    if !orientation.keys.is_empty()
-                        || orientation.expr.is_some()
-                        || scale.expr.is_some()
-                        || layer.auto_orient != effectcraft_project::AutoOrient::Off
+                    // Cameras and lights have no Scale; their Orientation is re-expressed alone.
+                    let scale = tr.get("scale");
+                    // Expression-driven values stay authored. Auto-orient replaces Orientation, except
+                    // a two-node rig, whose roll is re-expressed against its new aim.
+                    let two_node = (layer.is_camera() || layer.is_light()) && effectcraft_render::three_d::camera::is_two_node(layer);
+                    if orientation.expr.is_some()
+                        || scale.is_some_and(|scale| scale.expr.is_some())
+                        || (layer.auto_orient != effectcraft_project::AutoOrient::Off && !two_node)
                    {
                        return None;
                    }
-                    let pose = uniform_parent_pose(m, orientation.value.as_vec3())?;
-                    let factor = pose.1;
-                    let values_finite = std::iter::once(&scale.value)
-                        .chain(scale.keys.iter().map(|key| &key.value))
-                        .all(|value| value.as_vec3().iter().all(|v| (v * factor).is_finite()));
-                    let speeds_finite = scale.keys.iter().flat_map(|key| key.in_ease.iter().chain(&key.out_ease)).all(|ease| (ease.speed * factor).is_finite());
-                    (values_finite && speeds_finite).then_some(pose)
+                    let (rotation, factor) = uniform_rotation(m)?;
+                    let correction = if two_node {
+                        // A mirrored parent flips the aim, which this correction does not model.
+                        if factor <= 0.0 {
+                            return None;
+                        }
+                        let (w, h) = (comp.width as f64, comp.height as f64);
+                        let pos = ectx.v3(layer, tr, "position", [w / 2.0, h / 2.0, -1000.0]);
+                        let poi = ectx.v3(layer, tr, "poi", [w / 2.0, h / 2.0, 0.0]);
+                        aim_correction(rotation, [poi[0] - pos[0], poi[1] - pos[1], poi[2] - pos[2]])?
+                    } else {
+                        rotation
+                    };
+                    let orientation_finite = std::iter::once(&orientation.value)
+                        .chain(orientation.keys.iter().map(|key| &key.value))
+                        .all(|value| value.as_vec3().iter().all(|v| v.is_finite()));
+                    if !correction.0.iter().flatten().all(|v| v.is_finite()) || !orientation_finite {
+                        return None;
+                    }
+                    if let Some(scale) = scale {
+                        let values_finite = std::iter::once(&scale.value)
+                            .chain(scale.keys.iter().map(|key| &key.value))
+                            .all(|value| value.as_vec3().iter().all(|v| (v * factor).is_finite()));
+                        let speeds_finite = scale.keys.iter().all(|key| key.in_ease.iter().chain(&key.out_ease).all(|ease| (ease.speed * factor).is_finite()));
+                        if !values_finite || !speeds_finite {
+                            return None;
+                        }
+                    }
+                    Some(Pose3d { correction, factor })
                });
                fixes.push(ParentFix { layer: layer.id, m: effectcraft_geom::Mat3::IDENTITY, rotation: 0.0, scale: [1.0; 2], position_3d: Some(m), pose_3d });
            }
@@ -309,6 +510,8 @@ fn check_parent_chain(comp: &Comp, ids: &[LayerId], parent: Option<LayerId>, max

 pub(super) fn set_parent(s: &mut Session, p: &Value) -> Result<Value> {
    let (cid, ids) = layers_p(s, p)?;
+    // Locked layers keep their parent (several at once: the others are parented).
+    let ids = unlocked(s, cid, ids, "layer.setParent")?;
    let comp = s.project.comp(cid).ok_or(EngineError::NoComp)?;
    let parent = match p.get("parent") {
        None | Some(Value::Null) => None,
@@ -323,7 +526,7 @@ pub(super) fn set_parent(s: &mut Session, p: &Value) -> Result<Value> {
    let fixes = if compensate { parent_fixes(s, cid, &ids, parent) } else { vec![] };
    s.edit("Parent", None, |proj, _| {
        let comp = proj.comp_mut(cid).ok_or(EngineError::NoComp)?;
-        for l in comp.layers.iter_mut().filter(|l| ids.contains(&l.id)) {
+        for l in comp.layers.iter_mut_where(|l| ids.contains(&l.id)) {
            l.parent = parent;
            if let Some(f) = fixes.iter().find(|f| f.layer == l.id) {
                f.apply(l);
@@ -1,6 +1,6 @@
 use super::{
    BlendMode, EngineError, FrameBlend, ItemId, KV, Layer, LayerId, MatteKind, Quality, Result, Session, TrackMatte, Value, b_p, bad, json, layer_mut, layer_p,
-    layers_p, merge_p, resolve_layer, str_p,
+    layers_p, merge_p, resolve_layer, str_p, unlocked,
 };

 pub(super) fn set_switch(s: &mut Session, p: &Value) -> Result<Value> {
@@ -19,7 +19,7 @@ pub(super) fn set_switch(s: &mut Session, p: &Value) -> Result<Value> {
        let first = comp.layers.iter().find(|l| ids.contains(&l.id)).map(|l| switch_value(l, &name)).unwrap_or(Some(false));
        let Some(first) = first else { return Err(bad("layer.setSwitch", format!("unknown switch `{name}`"))) };
        let target = v.unwrap_or(!first);
-        for l in comp.layers.iter_mut().filter(|l| ids.contains(&l.id)) {
+        for l in comp.layers.iter_mut_where(|l| ids.contains(&l.id)) {
            set_switch_value(l, &name, target);
            last = target;
        }
@@ -55,7 +55,7 @@ fn set_switch_others(s: &mut Session, cid: ItemId, ids: &[LayerId], name: &str,
            alone &= on == (ids.contains(&l.id) == active);
        }
        let others = value.unwrap_or(alone == active);
-        for l in comp.layers.iter_mut().filter(|l| applies(l)) {
+        for l in comp.layers.iter_mut_where(|l| applies(l)) {
            let v = if ids.contains(&l.id) { active } else { others };
            set_switch_value(l, name, v);
        }
@@ -152,7 +152,7 @@ pub(super) fn set_comment(s: &mut Session, p: &Value) -> Result<Value> {
    let text = str_p(p, "comment").ok_or_else(|| bad("layer.setComment", "missing `comment`"))?.to_string();
    s.edit("Layer Comment", None, |proj, _| {
        let comp = proj.comp_mut(cid).ok_or(EngineError::NoComp)?;
-        for l in comp.layers.iter_mut().filter(|l| ids.contains(&l.id)) {
+        for l in comp.layers.iter_mut_where(|l| ids.contains(&l.id)) {
            l.comment = text.clone();
        }
        Ok(())
@@ -169,7 +169,7 @@ pub(super) fn blend(s: &mut Session, p: &Value) -> Result<Value> {
    }
    s.edit("Blending Mode", None, |proj, _| {
        let comp = proj.comp_mut(cid).ok_or(EngineError::NoComp)?;
-        for l in comp.layers.iter_mut().filter(|l| ids.contains(&l.id)) {
+        for l in comp.layers.iter_mut_where(|l| ids.contains(&l.id)) {
            l.blend_mode = match mode {
                Some(m) => m,
                None if step > 0 => l.blend_mode.next(),
@@ -181,33 +181,122 @@ pub(super) fn blend(s: &mut Session, p: &Value) -> Result<Value> {
    Ok(Value::Null)
 }

+/// `layer.setTrackMatte`: `layers` (or `layer`, else the first selected layer; locked ones left
+/// as they are) use `matte` as their track matte (none when null), in one undo step. `kind` sets the mode; `preserve` keeps
+/// each layer's own (Alpha for a layer without a matte), so changing the matte of several layers
+/// at once keeps their modes.
 pub(super) fn track_matte(s: &mut Session, p: &Value) -> Result<Value> {
-    let (cid, lid) = layer_p(s, p, "layer.setTrackMatte")?;
+    let (cid, ids) = match p.get("layers") {
+        Some(_) => layers_p(s, p)?,
+        None => layer_p(s, p, "layer.setTrackMatte").map(|(c, l)| (c, vec![l]))?,
+    };
+    // Locked layers keep their matte (several at once: the others get it).
+    let ids = unlocked(s, cid, ids, "layer.setTrackMatte")?;
    let comp = s.project.comp(cid).ok_or(EngineError::NoComp)?;
    let matte = match p.get("matte") {
        None | Some(Value::Null) => None,
        Some(v) => Some(resolve_layer(comp, v).ok_or_else(|| bad("layer.setTrackMatte", "no such matte layer"))?),
    };
-    let kind = str_p(p, "kind")
-        .map(|k| match k.to_ascii_lowercase().replace([' ', '_', '-'], "").as_str() {
+    if ids.is_empty() {
+        return Err(bad("layer.setTrackMatte", "no layers"));
+    }
+    if matte.is_some_and(|m| ids.contains(&m)) {
+        return Err(bad("layer.setTrackMatte", "a layer can't be its own matte"));
+    }
+    // None: each layer keeps its own mode.
+    let kind = match str_p(p, "kind").map(|k| k.to_ascii_lowercase().replace([' ', '_', '-'], "")) {
+        Some(k) if k == "preserve" => None,
+        Some(k) => Some(match k.as_str() {
            "alphainverted" | "alphainv" => MatteKind::AlphaInverted,
            "luma" => MatteKind::Luma,
            "lumainverted" | "lumainv" => MatteKind::LumaInverted,
            _ => MatteKind::Alpha,
-        })
-        .unwrap_or(MatteKind::Alpha);
+        }),
+        None => Some(MatteKind::Alpha),
+    };
    s.edit("Track Matte", None, |proj, _| {
        let comp = proj.comp_mut(cid).ok_or(EngineError::NoComp)?;
-        if let Some(m) = matte {
-            if m == lid {
-                return Err(bad("layer.setTrackMatte", "a layer can't be its own matte"));
-            }
-            if let Some(ml) = comp.layer_mut(m) {
-                ml.switches.video = false;
-            }
+        if let Some(ml) = matte.and_then(|m| comp.layer_mut(m)) {
+            ml.switches.video = false;
+        }
+        for lid in &ids {
+            let l = comp.layer_mut(*lid).ok_or(EngineError::NoComp)?;
+            let kind = kind.unwrap_or_else(|| l.track_matte.map(|m| m.kind).unwrap_or_default());
+            l.track_matte = matte.map(|layer| TrackMatte { layer, kind });
        }
-        comp.layer_mut(lid).ok_or(EngineError::NoComp)?.track_matte = matte.map(|layer| TrackMatte { layer, kind });
        Ok(())
    })?;
    Ok(Value::Null)
 }
+
+#[cfg(test)]
+mod track_matte_batch_tests {
+    use super::*;
+    use std::sync::Arc;
+
+    fn matte_of(s: &Session, id: u64) -> Option<(u64, MatteKind)> {
+        s.active_comp().unwrap().layer(LayerId(id)).unwrap().track_matte.map(|m| (m.layer.0, m.kind))
+    }
+
+    /// #1260: several layers take one matte layer at once, in one undo step; `kind: "preserve"`
+    /// keeps each one's mode; refused calls change nothing; one `layer` still works.
+    #[test]
+    fn several_layers_take_one_matte_and_keep_their_modes() {
+        let mut s = Session::default();
+        s.execute("comp.new", json!({"name":"Mattes","width":16,"height":16,"duration":1})).unwrap();
+        let [a, b, c, x, y] = ["A", "B", "C", "X", "Y"].map(|n| s.execute("layer.newSolid", json!({"name": n})).unwrap()["layer"].as_u64().unwrap());
+        s.execute("layer.setTrackMatte", json!({"layer": a, "matte": x, "kind": "luma"})).unwrap();
+        s.execute("layer.setTrackMatte", json!({"layer": b, "matte": x})).unwrap();
+        assert_eq!((matte_of(&s, a), matte_of(&s, b)), (Some((x, MatteKind::Luma)), Some((x, MatteKind::Alpha))), "one layer, as before");
+        let (before, undo) = (s.project.clone(), s.history.undo.len());
+        s.execute("layer.setTrackMatte", json!({"layers": [a, b, c], "matte": y, "kind": "preserve"})).unwrap();
+        assert_eq!(
+            [matte_of(&s, a), matte_of(&s, b), matte_of(&s, c)],
+            [Some((y, MatteKind::Luma)), Some((y, MatteKind::Alpha)), Some((y, MatteKind::Alpha))],
+            "each keeps its mode (Alpha without one)"
+        );
+        assert!(!s.active_comp().unwrap().layer(LayerId(y)).unwrap().switches.video, "the matte is hidden");
+        assert_eq!(s.history.undo.len(), undo + 1, "one undo step");
+        s.execute("edit.undo", json!({})).unwrap();
+        assert!(s.project.same_content(&before));
+        // Refused: a layer as its own matte, an unknown layer, no layers. Nothing changes.
+        for p in [
+            json!({"layers": [a, y], "matte": y}),
+            json!({"layers": [a, 9999], "matte": y}),
+            json!({"layers": [], "matte": y}),
+            json!({"layers": [a], "matte": 9999}),
+        ] {
+            let (project, revision) = (s.project.clone(), s.revision);
+            assert!(s.execute("layer.setTrackMatte", p.clone()).is_err(), "{p}");
+            assert!(Arc::ptr_eq(&project, &s.project) && s.revision == revision, "{p} changed nothing");
+        }
+        s.execute("layer.setTrackMatte", json!({"layers": [a, b], "matte": null})).unwrap();
+        assert_eq!((matte_of(&s, a), matte_of(&s, b)), (None, None), "both lose it");
+    }
+
+    /// Locked layers keep their parent and matte when they are among several (the others change),
+    /// and alone they are an error that changes nothing.
+    #[test]
+    fn locked_layers_keep_their_parent_and_matte() {
+        let mut s = Session::default();
+        s.execute("comp.new", json!({"name":"Locks","width":16,"height":16,"duration":1})).unwrap();
+        let [a, b, p, m] = ["A", "B", "P", "M"].map(|n| s.execute("layer.newSolid", json!({"name": n})).unwrap()["layer"].as_u64().unwrap());
+        s.execute("layer.setSwitch", json!({"layers": [b], "switch": "lock", "value": true})).unwrap();
+        let layer = |s: &Session, id: u64| s.active_comp().unwrap().layer(LayerId(id)).unwrap().clone();
+        s.execute("layer.setParent", json!({"layers": [a, b], "parent": p})).unwrap();
+        s.execute("layer.setTrackMatte", json!({"layers": [a, b], "matte": m, "kind": "preserve"})).unwrap();
+        s.execute("layer.trackMatte", json!({"layers": [a, b], "op": "luma"})).unwrap();
+        assert_eq!((layer(&s, a).parent, matte_of(&s, a)), (Some(LayerId(p)), Some((m, MatteKind::Luma))));
+        assert_eq!((layer(&s, b).parent, matte_of(&s, b)), (None, None), "the locked layer is left as it was");
+        for (cmd, p) in [
+            ("layer.setParent", json!({"layers": [b], "parent": p})),
+            ("layer.setTrackMatte", json!({"layers": [b], "matte": m})),
+            ("layer.trackMatte", json!({"layers": [b], "op": "alpha"})),
+        ] {
+            let (project, revision) = (s.project.clone(), s.revision);
+            let err = s.execute(cmd, p).unwrap_err();
+            assert!(err.to_string().contains("is locked"), "{cmd}: {err}");
+            assert!(Arc::ptr_eq(&project, &s.project) && s.revision == revision, "{cmd} changed nothing");
+        }
+    }
+}
@@ -18,7 +18,7 @@ pub(super) fn timing(s: &mut Session, p: &Value) -> Result<Value> {
        let comp = proj.comp_mut(cid).ok_or(EngineError::NoComp)?;
        let fd = comp.frame_duration();
        let comp_dur = comp.duration;
-        for l in comp.layers.iter_mut().filter(|l| ids.contains(&l.id)) {
+        for l in comp.layers.iter_mut_where(|l| ids.contains(&l.id)) {
            let shift = |l: &mut Layer, d: Tick| {
                l.start_time += d;
                l.in_point += d;
@@ -42,7 +42,9 @@ pub(super) fn timing(s: &mut Session, p: &Value) -> Result<Value> {
                    shift(l, d);
                }
                "trimInToTime" => l.in_point = t.min(l.out_point - fd),
-                "trimOutToTime" => l.out_point = t.max(l.in_point + fd),
+                // Alt+]: the Out edge lands one frame after the playhead, so its frame stays the
+                // layer's last visible one (as in After Effects), never before the In point.
+                "trimOutToTime" => l.out_point = t.max(l.in_point) + fd,
                _ => {
                    if let Some(d) = delta {
                        shift(l, d);
@@ -159,14 +161,14 @@ pub(super) fn arrange(s: &mut Session, p: &Value) -> Result<Value> {
                for i in 1..n {
                    if picked(&comp.layers[i]) && !picked(&comp.layers[i - 1]) {
                        let run_end = (i..n).find(|j| !picked(&comp.layers[*j])).unwrap_or(n);
-                        comp.layers[i - 1..run_end].rotate_left(1);
+                        comp.layers.rotate_range_left(i - 1..run_end, 1);
                    }
                }
            } else {
                for i in (0..n.saturating_sub(1)).rev() {
                    if picked(&comp.layers[i]) && !picked(&comp.layers[i + 1]) {
                        let run_start = (0..=i).rev().find(|j| !picked(&comp.layers[*j])).map_or(0, |j| j + 1);
-                        comp.layers[run_start..=i + 1].rotate_right(1);
+                        comp.layers.rotate_range_right(run_start..=i + 1, 1);
                    }
                }
            }
@@ -74,14 +74,39 @@ pub(super) fn transform_op(s: &mut Session, p: &Value) -> Result<Value> {
    let op = str_p(p, "op").unwrap_or("reset").to_string();
    let comp = s.project.comp(cid).ok_or(EngineError::NoComp)?.clone();
    let t = s.time();
-    let sizes: Vec<(LayerId, (u32, u32))> =
-        comp.layers.iter().filter(|l| ids.contains(&l.id)).map(|l| (l.id, effectcraft_render::source_size(&s.project, l))).collect();
+    // A shape or text layer has no source item, so source_size is (0, 0): the fit ops size it by
+    // its painted bounds at the current time instead, and anchor at the bounds' centre — content
+    // bounds live in layer space, where a shape is centred on the origin and text sits above its
+    // baseline, so (w/2, h/2) would push it off-centre (#2198). Reset and the other ops keep the
+    // source size.
+    let ectx = effectcraft_render::EvalCtx {
+        expr: s.expr.as_deref(),
+        footage: Some(s.footage.as_ref()),
+        ..effectcraft_render::EvalCtx::new(&s.project, cid, &comp, t)
+    };
+    let fitting = matches!(op.as_str(), "fit" | "fitWidth" | "fitHeight");
+    let sizes: Vec<(LayerId, [f64; 2], [f64; 2])> = comp
+        .layers
+        .iter()
+        .filter(|l| ids.contains(&l.id))
+        .map(|l| {
+            let (w, h) = effectcraft_render::source_size(&s.project, l);
+            if fitting && (w == 0 || h == 0) {
+                match effectcraft_render::content_bounds(&ectx, l).filter(|b| b.iter().all(|v| v.is_finite()) && b[2] > b[0] && b[3] > b[1]) {
+                    Some(b) => (l.id, [b[2] - b[0], b[3] - b[1]], [(b[0] + b[2]) / 2.0, (b[1] + b[3]) / 2.0]),
+                    None => (l.id, [0.0; 2], [0.0; 2]),
+                }
+            } else {
+                (l.id, [w as f64, h as f64], [w as f64 / 2.0, h as f64 / 2.0])
+            }
+        })
+        .collect();
    s.edit("Transform", None, |proj, _| {
-        for (lid, (w, h)) in &sizes {
+        for (lid, size, anchor) in &sizes {
            let l = layer_mut(proj, cid, *lid)?;
            let lt = l.layer_time(t);
            let (cw, ch) = (comp.width as f64, comp.height as f64);
-            let (w, h) = (*w as f64, *h as f64);
+            let (w, h) = (size[0], size[1]);
            let Some(tr) = l.transform_mut() else { continue };
            let set = |tr: &mut PropGroup, m: &str, v: KV| {
                if let Some(pr) = tr.get_mut(m) {
@@ -105,11 +130,15 @@ pub(super) fn transform_op(s: &mut Session, p: &Value) -> Result<Value> {
                        "fitHeight" => (ch / h, ch / h),
                        _ => (cw / w, ch / h),
                    };
+                    // A tiny shape's bounds can overflow the scale; refuse rather than write infinity.
+                    if !(sx * 100.0).is_finite() || !(sy * 100.0).is_finite() {
+                        return Err(EngineError::Other(format!("layer {} is too small to fit to the composition", lid.0)));
+                    }
                    let z = |m: &str, d: f64| tr.get(m).map(|p| p.value_at(lt).as_vec3()[2]).unwrap_or(d);
                    let (sz, az) = (z("scale", 100.0), z("anchor", 0.0));
                    set(tr, "scale", KV::Vec3([sx * 100.0, sy * 100.0, sz]));
                    update_position(tr, lt, |p| [cw / 2.0, ch / 2.0, p[2]]);
-                    set(tr, "anchor", KV::Vec3([w / 2.0, h / 2.0, az]));
+                    set(tr, "anchor", KV::Vec3([anchor[0], anchor[1], az]));
                }
                "flipH" | "flipV" => {
                    let cur = tr.get("scale").map(|p| p.value_at(lt).as_vec3()).unwrap_or([100.0; 3]);
@@ -61,7 +61,7 @@ fn quality(s: &mut Session, p: &Value) -> Result<Value> {
        q => return Err(bad("layer.quality", format!("quality must be best|draft|wireframe, not `{q}`"))),
    };
    s.edit("Layer Quality", None, |proj, _| {
-        for l in proj.comp_mut(cid).ok_or(EngineError::NoComp)?.layers.iter_mut().filter(|l| ids.contains(&l.id)) {
+        for l in proj.comp_mut(cid).ok_or(EngineError::NoComp)?.layers.iter_mut_where(|l| ids.contains(&l.id)) {
            l.switches.quality = q;
        }
        Ok(())
@@ -84,7 +84,7 @@ fn sampling(s: &mut Session, p: &Value) -> Result<Value> {
        q => q,
    };
    s.edit("Layer Sampling", None, |proj, _| {
-        for l in proj.comp_mut(cid).ok_or(EngineError::NoComp)?.layers.iter_mut().filter(|l| ids.contains(&l.id)) {
+        for l in proj.comp_mut(cid).ok_or(EngineError::NoComp)?.layers.iter_mut_where(|l| ids.contains(&l.id)) {
            l.switches.sampling = q;
        }
        Ok(())
@@ -101,7 +101,7 @@ fn frame_blending(s: &mut Session, p: &Value) -> Result<Value> {
        m => return Err(bad("layer.frameBlending", format!("mode must be off|frameMix|pixelMotion, not `{m}`"))),
    };
    s.edit("Frame Blending", None, |proj, _| {
-        for l in proj.comp_mut(cid).ok_or(EngineError::NoComp)?.layers.iter_mut().filter(|l| ids.contains(&l.id)) {
+        for l in proj.comp_mut(cid).ok_or(EngineError::NoComp)?.layers.iter_mut_where(|l| ids.contains(&l.id)) {
            l.switches.frame_blend = m;
        }
        Ok(())
@@ -116,7 +116,7 @@ fn hide_other_video(s: &mut Session, p: &Value) -> Result<Value> {
    s.edit("Hide Other Video", None, |proj, _| {
        // Every layer has a Video switch (nulls, cameras and lights included, as the Timeline's
        // eye cell shows): the selection stays shown.
-        for l in proj.comp_mut(cid).ok_or(EngineError::NoComp)?.layers.iter_mut().filter(|l| !ids.contains(&l.id)) {
+        for l in proj.comp_mut(cid).ok_or(EngineError::NoComp)?.layers.iter_mut_where(|l| !ids.contains(&l.id)) {
            l.switches.video = false;
        }
        Ok(())
@@ -130,7 +130,7 @@ fn show_all_video(s: &mut Session, p: &Value) -> Result<Value> {
        let c = proj.comp_mut(cid).ok_or(EngineError::NoComp)?;
        // Track mattes stay hidden (their video switch is off by design).
        let mattes: Vec<LayerId> = c.layers.iter().filter_map(|l| l.track_matte.map(|m| m.layer)).collect();
-        for l in c.layers.iter_mut().filter(|l| !mattes.contains(&l.id)) {
+        for l in c.layers.iter_mut_where(|l| !mattes.contains(&l.id)) {
            l.switches.video = true;
        }
        Ok(())
@@ -154,7 +154,7 @@ fn expressions(s: &mut Session, p: &Value) -> Result<Value> {
    let on = b_p(p, "enabled").unwrap_or(true);
    let n = s.edit(if on { "Enable Expressions" } else { "Disable Expressions" }, None, |proj, _| {
        let mut n = 0;
-        for l in proj.comp_mut(cid).ok_or(EngineError::NoComp)?.layers.iter_mut().filter(|l| ids.contains(&l.id)) {
+        for l in proj.comp_mut(cid).ok_or(EngineError::NoComp)?.layers.iter_mut_where(|l| ids.contains(&l.id)) {
            l.props.walk_mut(&mut |pr| {
                if let Some(e) = &mut pr.expr {
                    e.enabled = on;
@@ -586,7 +586,7 @@ fn markers_lock(s: &mut Session, p: &Value) -> Result<Value> {
    let r = s.edit("Lock Markers", None, |proj, _| {
        let c = proj.comp_mut(cid).ok_or(EngineError::NoComp)?;
        let target = v.unwrap_or_else(|| !c.layers.iter().find(|l| ids.contains(&l.id)).is_some_and(|l| l.markers_locked));
-        for l in c.layers.iter_mut().filter(|l| ids.contains(&l.id)) {
+        for l in c.layers.iter_mut_where(|l| ids.contains(&l.id)) {
            l.markers_locked = target;
        }
        Ok(target)
@@ -597,7 +597,7 @@ fn markers_lock(s: &mut Session, p: &Value) -> Result<Value> {
 fn delete_all_markers(s: &mut Session, p: &Value) -> Result<Value> {
    let (cid, ids) = layers_p(s, p)?;
    s.edit("Delete All Markers", None, |proj, _| {
-        for l in proj.comp_mut(cid).ok_or(EngineError::NoComp)?.layers.iter_mut().filter(|l| ids.contains(&l.id) && !l.markers_locked) {
+        for l in proj.comp_mut(cid).ok_or(EngineError::NoComp)?.layers.iter_mut_where(|l| ids.contains(&l.id) && !l.markers_locked) {
            l.markers.clear();
        }
        Ok(())
@@ -609,6 +609,7 @@ fn delete_all_markers(s: &mut Session, p: &Value) -> Result<Value> {

 fn track_matte_op(s: &mut Session, p: &Value) -> Result<Value> {
    let (cid, ids) = layers_p(s, p)?;
+    let ids = super::unlocked(s, cid, ids, "layer.trackMatte")?;
    let op = str_p(p, "op").ok_or_else(|| bad("layer.trackMatte", "missing `op`"))?.to_string();
    let kind = match op.as_str() {
        "alpha" => Some(MatteKind::Alpha),
@@ -34,7 +34,7 @@ fn time_stretch(s: &mut Session, p: &Value) -> Result<Value> {
    let fd = comp_rate.frame_duration();
    s.edit(if reverse { "Time-Reverse Layer" } else { "Time Stretch" }, None, |proj, _| {
        let comp = proj.comp_mut(cid).ok_or(EngineError::NoComp)?;
-        for l in comp.layers.iter_mut().filter(|l| ids.contains(&l.id)) {
+        for l in comp.layers.iter_mut_where(|l| ids.contains(&l.id)) {
            let old = l.stretch;
            if reverse {
                // Keep the in/out points; play the visible span backwards.
@@ -109,7 +109,7 @@ fn enable_time_remap(s: &mut Session, p: &Value) -> Result<Value> {
        let mut next = proj.next_id;
        let comp = proj.comp_mut(cid).ok_or(EngineError::NoComp)?;
        let mut on = false;
-        for l in comp.layers.iter_mut().filter(|l| ids.contains(&l.id) && remappable(l)) {
+        for l in comp.layers.iter_mut_where(|l| ids.contains(&l.id) && remappable(l)) {
            let has = l.props.get("timeRemap").is_some();
            let target = want.unwrap_or(!has);
            on |= target;
@@ -185,7 +185,16 @@ fn freeze(s: &mut Session, p: &Value, last: bool) -> Result<Value> {
        return Err(bad("layer.freezeFrame", "freezing needs a footage or composition layer"));
    }
    // What each layer shows now (honouring an existing remap) — evaluated before the edit.
-    let ectx = effectcraft_render::EvalCtx { project: &s.project, comp_id: cid, comp, time: cti, expr: s.expr.as_deref(), footage: Some(s.footage.as_ref()) };
+    let ectx = effectcraft_render::EvalCtx {
+        project: &s.project,
+        comp_id: cid,
+        comp,
+        time: cti,
+        expr: s.expr.as_deref(),
+        footage: Some(s.footage.as_ref()),
+        property_overrides: &[],
+        media_overrides: &[],
+    };
    let now: Vec<(effectcraft_project::LayerId, f64)> = comp
        .layers
        .iter()
@@ -102,11 +102,39 @@ fn quote(s: &str) -> String {

 /// The AE expression reference to property `uid` of `target` as seen from a property of `from`.
 pub(crate) fn reference(comp: &Comp, from: &Layer, target: &Layer, uid: Uid, compact: bool) -> Option<String> {
+    reference_with(comp, from, target, uid, compact, false)
+}
+
+/// [`reference`], with the properties inside an effect selected by their index (`by_index`, an
+/// Alt pick whip in After Effects): `effect("Color Control")(1)` rather than `("Color")`. The
+/// effect keeps its name. An index is the property's place among its group's children, as an
+/// expression's `(1)` reads it: it follows a renamed parameter, not one moved to another place.
+pub(crate) fn reference_with(comp: &Comp, from: &Layer, target: &Layer, uid: Uid, compact: bool, by_index: bool) -> Option<String> {
    let chain = target.props.node_chain(uid)?;
+    // Each node's one-based index among its group's children, and whether it lies inside an
+    // effect (below the effect itself): those are selected by index with `by_index`.
+    let mut parent = &target.props;
+    let mut depth_in_effects: Option<usize> = None;
+    let mut by_number: Vec<Option<usize>> = vec![];
+    for n in &chain {
+        let at = parent.children.iter().position(|c| c.uid() == n.uid()).map(|i| i + 1);
+        by_number.push(at.filter(|_| by_index && depth_in_effects.is_some_and(|d| d >= 1)));
+        depth_in_effects = match depth_in_effects {
+            Some(d) => Some(d + 1),
+            None => (n.match_id() == "effects").then_some(0),
+        };
+        if let Node::Group(g) = n {
+            parent = g;
+        }
+    }
+    let selector = |i: usize, label: &str| match by_number.get(i).copied().flatten() {
+        Some(at) => format!("({at})"),
+        None => format!("({})", quote(label)),
+    };
    let mut parts: Vec<String> = vec![];
    let mut pending: Option<&str> = None;
    let mut in_effect = false;
-    for n in chain {
+    for (i, n) in chain.iter().copied().enumerate() {
        if let Some(f) = pending.take() {
            parts.push(format!("{f}({})", quote(n.name())));
            in_effect |= f == "effect";
@@ -119,7 +147,7 @@ pub(crate) fn reference(comp: &Comp, from: &Layer, target: &Layer, uid: Uid, com
            (Node::Group(_), "transform") if !in_effect => parts.push("transform".into()),
            (Node::Group(_), "text") if !in_effect => parts.push("text".into()),
            (Node::Prop(_), "sourceText") => parts.push("sourceText".into()),
-            _ if in_effect => parts.push(format!("({})", quote(n.name()))),
+            _ if in_effect => parts.push(selector(i, n.name())),
            _ => parts.push(camel(n.name())),
        }
    }
@@ -127,10 +155,9 @@ pub(crate) fn reference(comp: &Comp, from: &Layer, target: &Layer, uid: Uid, com
    let _ = comp;
    if !compact {
        // Match names: language-independent, like After Effects with Compact English off.
-        let chain = target.props.node_chain(uid)?;
        let mut out = if from.id == target.id { "thisLayer".to_string() } else { format!("thisComp.layer({})", quote(&target.name)) };
-        for n in chain {
-            out.push_str(&format!("({})", quote(n.match_id())));
+        for (i, n) in chain.iter().copied().enumerate() {
+            out.push_str(&selector(i, n.match_id()));
        }
        return Some(out);
    }
@@ -161,7 +188,9 @@ fn pick_whip(s: &mut Session, p: &Value) -> Result<Value> {
    let comp = s.project.comp(cid).ok_or(EngineError::NoComp)?;
    let from = comp.layer(lid).ok_or(EngineError::NoComp)?;
    let target = comp.layer(tl).ok_or(EngineError::NoComp)?;
-    let r = reference(comp, from, target, tu, s.prefs.general.expression_pick_whip_compact).ok_or_else(|| bad("prop.pickWhip", "no such target property"))?;
+    let by_index = b_p(p, "byIndex").unwrap_or(false);
+    let r = reference_with(comp, from, target, tu, s.prefs.general.expression_pick_whip_compact, by_index)
+        .ok_or_else(|| bad("prop.pickWhip", "no such target property"))?;
    let (me, them) = (from.props.find(uid).ok_or(EngineError::NoComp)?, target.props.find(tu).ok_or(EngineError::NoComp)?);
    let (dm, dt) = (dims(from, me), dims(target, them));
    // Dropped on one of the target's values: that dimension (`position[0]`), as in After Effects.
@@ -206,7 +235,7 @@ pub fn specs() -> Vec<CommandSpec> {
            "Pick Whip (Link Property)",
            [],
            None,
-            "{layer?, path|prop, target: {layer, path|prop, dimension?}, expression?, range?: [start, end]} → sets an AE reference expression (`dimension`: one of the target's values, `position[0]`; with `expression`: inserts it there, replacing the characters in `range`, default the end)",
+            "{layer?, path|prop, target: {layer, path|prop, dimension?}, expression?, range?: [start, end], byIndex?: bool} → sets an AE reference expression (`dimension`: one of the target's values, `position[0]`; with `expression`: inserts it there, replacing the characters in `range`, default the end; `byIndex`: an effect's properties by their index, `effect(\"Color Control\")(1)`, as an Alt pick whip does)",
            has_layers,
            pick_whip
        ),