The user's architectural question -- 'should animation and velocity even be
allowed to be uncoupled?' -- is decomp-CONFIRMED correct: the original peer
(FUN_004ab430 -> FUN_004ab1c8) drove POSITION FROM THE CLIP'S ROOT TRAVEL
between records (feet<->ground locked by construction) with a pose-sync
offset decay absorbing record corrections. Our port dead-reckons position
from velocity while the legs run on commanded speed -- the two only agree at
steady state, mismatching exactly during speed changes (the reported glitch).
This commit lands the peer half of the coupled architecture, env-gated:
- BT_ROOT_POS=1: peer position += clip travel rotated by heading (mirror of
the master world-step @3325, == IntegrateMotion tail @004ab1c8); pose
records absorbed via the authentic offset-decay (motionEventVector
mechanism) instead of snapping.
- Measured A/B (through-zero sweep circle, harshest speed-change regime):
velocity-lerp (default): step ratio 1.0022 (clean)
root-motion + sparse records: 11-17u anchor snaps (master's velocity
mirror no longer models a gait-driven peer -> under-sends)
root-motion + dense + offset-decay: evenness OK but ratio 1.86 --
authority tug-of-war (double-authoring, exactly the D5 risk).
CONCLUSION: the coupled peer requires the MASTER side of the original
architecture too (gait-driven send-gate mirror / channel-B IntegrateMotion
projection) -- a coherent rebuild for a fresh session, not a peer-only
patch. Default therefore stays velocity dead-reckon.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
