From aa300d7f2e6b8a7dfbb170bd5cac43469c0b27c6 Mon Sep 17 00:00:00 2001 From: tylerjenningsw Date: Tue, 13 Oct 2026 21:59:03 -0400 Subject: [PATCH] Render: CC Particle World layers with expressions aren't layer cached (#1373) The simulation checks its checkpoints against the Birth Rate history, but a cached layer is returned before the effect runs. The layer key sees the layer's keyframes and its current values, not what an expression returned at earlier times: a Birth Rate expression reading another layer could change the history while the current rate, 0, stayed the same. effects::reads_param_history names CC Particle World. The renderer already declines to cache layers whose time effects (ec.time.*) meet expressions. It now treats Particle World the same way, in the layer key, the input key (only for the effects that input runs) and the dependency walk. --- crates/effects/src/lib.rs | 7 ++++++ crates/render/src/cache.rs | 29 ++++++++++++++++++------- crates/render/src/cache/dependencies.rs | 6 ++--- 3 files changed, 31 insertions(+), 11 deletions(-) diff --git a/crates/effects/src/lib.rs b/crates/effects/src/lib.rs index e7d43f1ec..645ae20bc 100644 --- a/crates/effects/src/lib.rs +++ b/crates/effects/src/lib.rs @@ -1248,6 +1248,13 @@ 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 (CC Particle World samples its +/// 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 { + id == "ec.sim.ccparticleworld" +} + /// Run an effect on a buffer. pub fn apply(spec: &EffectSpec, ctx: &EffectCtx, buf: Buf) -> Buf { (spec.render)(ctx, buf) diff --git a/crates/render/src/cache.rs b/crates/render/src/cache.rs index bae12d1e3..47b2c0ebd 100644 --- a/crates/render/src/cache.rs +++ b/crates/render/src/cache.rs @@ -484,10 +484,11 @@ fn hash_values(h: &mut KeyHasher, ctx: &EvalCtx, layer: &Layer, g: &PropGroup) { /// time, or `None` when the layer must not be cached (footage, precomps, cameras, adjustment /// layers…). pub fn layer_key(ctx: &EvalCtx, layer: &Layer, scale: f64, draft: bool, blur: bool) -> Option { - // Time effects see property values at other times. Keyframes are part of the hashed - // structure (and the layer time is folded in), but expressions may read other layers at - // those times, which the key cannot see: such layers are not cached. - if reads_other_times(layer) && layer.props.children.iter().any(|c| matches!(c, Node::Group(g) if g.match_id != "transform" && has_expression(g))) { + // Time effects (and CC Particle World's Birth Rate history) see property values at other + // times. Keyframes are part of the hashed structure (and the layer time is folded in), but + // expressions may read other layers at those times, which the key cannot see: such layers + // are not cached. + if history_unkeyable(layer, None) { return None; } key_with(ctx, layer, scale, draft, blur, false) @@ -497,7 +498,7 @@ pub fn layer_key(ctx: &EvalCtx, layer: &Layer, scale: f64, draft: bool, blur: bo /// effects (see `Renderer::layer_input`). Unlike [`layer_key`], footage layers are cached here /// (keyed by item and source time), since Time effects read many neighbouring frames. pub fn input_key(ctx: &EvalCtx, layer: &Layer, scale: f64, draft: bool, blur: bool, effects: usize) -> Option { - if layer.switches.adjustment { + if layer.switches.adjustment || history_unkeyable(layer, Some(effects)) { return None; } let base = key_any(ctx, layer, scale, draft, blur, true, Some(effects))?; @@ -506,14 +507,26 @@ pub fn input_key(ctx: &EvalCtx, layer: &Layer, scale: f64, draft: bool, blur: bo Some(h.finish()) } -/// Does the layer run an effect that reads the layer at other times (Echo, Timewarp…)? -fn reads_other_times(layer: &Layer) -> bool { +/// Does the layer run (among its first `effects` effects, all when `None`) an effect that reads +/// the layer at other times (Echo, Timewarp…) or its own parameters' history (CC Particle +/// World's Birth Rate, #1373)? +fn reads_other_times(layer: &Layer, effects: Option) -> bool { layer.switches.effects && layer.effects().is_some_and(|fx| { - fx.groups().any(|g| g.enabled && matches!(&g.kind, effectcraft_project::GroupKind::Effect { effect } if effect.starts_with("ec.time."))) + fx.groups().take(effects.unwrap_or(usize::MAX)).any(|g| { + g.enabled + && matches!(&g.kind, effectcraft_project::GroupKind::Effect { effect } + if effect.starts_with("ec.time.") || effectcraft_effects::reads_param_history(effect)) + }) }) } +/// The layer reads values at other times (see [`reads_other_times`]) and has expressions +/// (outside Transform), whose results at those times the key can't see. +fn history_unkeyable(layer: &Layer, effects: Option) -> bool { + reads_other_times(layer, effects) && layer.props.children.iter().any(|c| matches!(c, Node::Group(g) if g.match_id != "transform" && has_expression(g))) +} + fn has_expression(g: &PropGroup) -> bool { g.children.iter().any(|c| match c { Node::Prop(p) => p.has_expression(), diff --git a/crates/render/src/cache/dependencies.rs b/crates/render/src/cache/dependencies.rs index eaccd0582..dfb80479e 100644 --- a/crates/render/src/cache/dependencies.rs +++ b/crates/render/src/cache/dependencies.rs @@ -7,7 +7,7 @@ use effectcraft_project::{ItemId, ItemKind, Layer, LayerId, LayerSource, Node, P use std::hash::Hash; pub(super) fn hash(h: &mut KeyHasher, ctx: &EvalCtx, layer: &Layer, effects: Option) -> Option<()> { - let mut deps = Dependencies { h, path: vec![(ctx.comp_id, layer.id)], remaining: 1024, other_times: super::reads_other_times(layer) }; + let mut deps = Dependencies { h, path: vec![(ctx.comp_id, layer.id)], remaining: 1024, other_times: super::reads_other_times(layer, None) }; deps.effects(ctx, layer, effects) } @@ -21,7 +21,7 @@ struct Dependencies<'a> { impl Dependencies<'_> { fn effects(&mut self, ctx: &EvalCtx, layer: &Layer, limit: Option) -> Option<()> { let previous = self.other_times; - self.other_times |= super::reads_other_times(layer); + self.other_times |= super::reads_other_times(layer, None); if layer.switches.effects && let Some(fx) = layer.effects() { @@ -69,7 +69,7 @@ impl Dependencies<'_> { return None; } self.remaining = self.remaining.checked_sub(1)?; - if (self.other_times || super::reads_other_times(layer)) && super::has_expression(&layer.props) { + if (self.other_times || super::reads_other_times(layer, None)) && super::has_expression(&layer.props) { return None; } self.path.push(id);