§36's simulation option: who integrates positions and velocities.
"cpu" — the emitter's own loop (emitter.ts), the default and the
only §33 same-runtime tier.
"gpu" — a bound ParticleGpuSimulation integrates on the
device; the pool's position/velocity lanes hold spawn-time values
only thereafter. See ParticleGpuSimulation for the contract
and the determinism posture.
Widened from the historical type-level absence in the same change that
wired the WebGPU integrator to the emitter (R-31 residue, 2026-08-29) —
the recorded WP-9.1 rule: an option that silently does nothing is worse
than one that does not exist yet, so the spelling and the function arrive
together.
§36's
simulationoption: who integrates positions and velocities."cpu"— the emitter's own loop (emitter.ts), the default and the only §33same-runtimetier."gpu"— a bound ParticleGpuSimulation integrates on the device; the pool's position/velocity lanes hold spawn-time values only thereafter. See ParticleGpuSimulation for the contract and the determinism posture.Widened from the historical type-level absence in the same change that wired the WebGPU integrator to the emitter (R-31 residue, 2026-08-29) — the recorded WP-9.1 rule: an option that silently does nothing is worse than one that does not exist yet, so the spelling and the function arrive together.