With a Birth Rate keyed into a burst, the GPU's particles match the CPU
simulation through the burst and after it. A second history with the
same system key, whose burst starts later (so the same ids are born at
other steps), isn't resumed from the first history's GPU checkpoints.
The issue's scene: a Birth Rate keyed 3 until 0.5 s then 0 matches the
constant rate during the burst, still draws the burst at 0.9 s with no
new births, and is empty once Longevity has run out. Moving the earlier
key changes the 0.9 s frame through the layer cache. Layers offset by
0.5 s or stretched 200 % sample their own layer times.
A burst lives on after the rate drops to 0: as a constant rate during
it, only its particles afterwards, still moving, gone after their
Longevity. Another effect's history isn't used. A ramp bears what each
moment asked for. Seeking backward and forward matches a simulation
from 0. Moving an earlier key isn't served from stale checkpoints with
the same current rate. A constant rate is unchanged. The birth schedule
matches the CPU's ids.
The simulation runs from layer time 0, but it used the Birth Rate of the
rendered frame for every step. A rate keyed from 3 down to 0 simulated
no births at all once it reached 0, so the burst's particles vanished
that frame although their Longevity had not run out. A ramped rate was
simulated as if its current value had always applied.
Each step now samples Birth Rate at its own layer time through
EffectHost::param_at (with the effect's own index). Without such a host
the current value applies throughout, as before. Particles already alive
keep moving and ageing whatever the rate. The carry and particle ids
continue across rate changes.
Birth Rate is left out of the simulation cache key, so an animated rate
no longer restarts the simulation every frame. In its place:
- The CPU state keeps a hash of the rates it was stepped with (hist). A
checkpoint is resumed only when that matches the current history, so
moving an earlier key is never served from a stale checkpoint.
- The GPU gets the birth schedule of the sampled rates (births_at). Its
checkpoints record which births they hold, and are resumed only when
the request's births before that step are the same.
A constant Birth Rate gives exactly the particles it did. CC Particle
Systems II and CC Mr. Mercury keep their constant-rate simulation.
psim::births_at builds the GPU's birth schedule (the birth step of every
particle id) from the rate of each step, with the CPU step's carry
arithmetic. births() for a constant rate now uses it. It stops as soon
as the cap would be passed, before adding a step's births, so a huge
rate can't build a huge list first.
SimCache::run_where takes a check on each checkpoint (its step and
state). A simulation whose steps depend on inputs outside its key, such
as a parameter's values over time, resumes only from a checkpoint
reached with the same inputs. A fresh checkpoint now replaces one at the
same step, so a changed history doesn't leave stale checkpoints behind.
run() is run_where with no check.
EffectHost::param_at(effect_index, id, layer_time) evaluates a single
parameter (by its flattened id, such as birthRate or group/param) of the
effect at that index in the layer's stack. A simulation can then sample
one parameter at every step without flattening the whole effect each
time.
The effect index is passed in, rather than read from the renderer's
running-effect index as params_at does: GPU-batched effects never update
that index, so a batched effect would read another effect's parameters.
The renderer's implementation walks the effect group by match id and
evaluates just that property (keyframes and expressions) at the comp
time of the layer time.
- Keyboard Shortcuts: Enter is not Delete while the delete confirmation is open (#1113 with #1019).
- Speed graph drag test compares proportions, since the Graph Editor now fits its selection (#1182 with #1109).
- Spanish panel test no longer demands the Chinese catalogs' exact rows (#996 with #1189, #1019).
- Object Matte gets its Simplified Chinese effect-name row (#1199 with #792).
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
- Cryptomatte (#1183): planes shorter than the image read as empty instead of panicking.
- layer.addMarker (#1180): a comp marker no longer replaces one at the same time.
- Desktop (#1005): ignore macOS's -psn_ argument instead of refusing to launch.
- Doc comments put back on their own items (#1153, #1037).
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
The six PSD PRs merged one by one leave #1131's test calling samples()/to_rgb(), which #1139
replaced; vangel76's integration draft #1149 has the adapted version.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
The nightly FreeBSD run measured 119 ms/frame against a 100 ms limit: the mean included
Tracker::new and any scheduling stalls on the two-core VM. The best single step with a
250 ms bound still catches an order-of-magnitude regression.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
tylerjenningsw