User pinpointed it: the per-stride 'static' was NOT the footstep sample -- it
was the ambient engine hum being interrupted in time with the footfalls.
Diagnosis (live tape): EnginePower01 was caught in a rapid Play->Stop cycle
(80x/session). The idle-hum is gated by authored LocalVelocity triggers (hum
ON in speed [1,20], OFF above 20) -- and the port's localVelocity is a RAW
per-frame position derivative that pulses with every stride (gait acceleration
+ ground-snap bob). At walking speed |v| straddles the 20 band edge, so the
trigger Start/Stop-flapped the hum on every foot plant; at run |v| >> 20 keeps
it off (matching 'goes away at higher speeds').
Fix: ~0.25s exponential filter on the PUBLISHED localVelocity.linearMotion
(fwd + vertical) -- kills the stride ripple, tracks real speed changes within
a couple strides. The physics worldLinearVelocity (StaticBounce, collision
damage pricing) is untouched; update records + the impact gate get the
smoother value (both benefit).
VERIFIED: EnginePower 1 play / 0 stops for the whole run (was 80 stop-cycles);
FootFall cycles normally per stride; gear shifts/windup lifecycle intact.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
