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.
A layer selected by another layer's effect (Displacement Map, Blend...) had
its structure, values, matrix and time hashed into the owner's key, but not
the comp camera/lights its own scene-reading effects (Caustics, CC Particle
World...) see. The owner's key included the scene only when the owner itself
ran such an effect, and a cached owner never runs the selected layer's
effects, so moving the camera or a light reused stale owner pixels.
Dependencies::layer now hashes comp_scene for every selected (or nested)
layer that reads it, with the same policy as owner keys.
Fixes#1252
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01N9kwMcw2pYQ5fSjKa3ZPnh
tylerjenningsw