User report: footfalls silent for the first 10-20 s of every mission (all
mechs), then solid. Root cause was three interlocking layers, each measured
with timestamped traces:
1. The authored footstep volume chain (LocalAcceleration [0,10]->ctl100 +
LocalVelocity [0,0.6]->ctl101 through authored N=30/N=15
AudioControlSmoothers, fill 0) hangs off the SOURCE's watcher chain
(scale watches smoother watches mixer watches source), and an idle
source's chain executes only at Start attempts -- one smoother sample
per stride.
2. Each hop is frame-gated (AudioComponent::ExecuteWatchers,
DefaultAudioFrameDelay), so any burst collapses to one execution.
3. The transient drop gate (vol < 0.3, AUDREND) rejected every Start while
the smoother average crawled up 1/30th per attempt -> ~25 dropped strides
before the first audible step, then per-frame execution while playing
kept it warm forever ("solid after that").
Fixes (engine-level, each documented in place):
- AudioScaleOf<T>::Execute now sends EVERY poll (scales are continuous
value-feeders; the base bitwise change-gate -- Motion::operator== is
memcmp -- froze on our deterministic gait math, where the original's
noisy physics floats never bit-repeated. Triggers/matchers keep the
change gate: their semantics are edge-based).
- Component/AudioComponent::PrimeWatchers(passes): recursive, GATE-FREE
watcher pump; AUDREND runs 30 passes on every transient Start request so
the authored smoothers evaluate at their true steady state before the
drop gate reads the volume.
- localAcceleration derives via the binary's exact structure: 15-sample
ring buffers of the raw position derivative + dt (ctor part_012.c:9836,
derive :15169-15195), in the PerformAndWatch tail so it runs every frame.
- AttributeWatcherOf::GrabCurrentValue private -> protected (the scale
override calls it).
Verified (30 s walk from cold start): drops 25 -> 3 (the survivors are
authentic quiet-stride gating: first gentle strides at vol ~0.28 vs the 0.3
gate), footfalls deliver from the first stride, 43 delivered with live
per-stride gain variation. Diag traces added: [accwatch]/[fsscale]/
[smooth]/[smoothcfg]/[motionscalecfg] + timestamps on DROP/volset.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
