- Elbow stored as an angle around the arm axis vs a torso-frame reference: 85% hand-suggested,
from the controller pose (not the physics palm), clamped +-110 deg, 6 rad/s rate limit
(flip spike: 1.8 cm/tick max vs 13.8 unclamped)
- PhysicsArms.ConstrainHand: while an arm segment is in contact the hand may lead the
forearm end by 3 cm; PhysicsHands applies it and suspends stuck-snap while active
- ArmSpike: forearm-rest-over-anvil (owner pose: collider fine, drawn forearm 3.9 cm -> 0),
flip sweep, bar test now asserts the hand is held back; all six spikes PASS x3
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
- BodyMath.RotationError: atan2-based shortest-arc error (no NaN, no GetAxis gain collapse
inside 0.16 deg); used by PhysicsTorso orientation servo and PhysicsHands rotation lock
- BodyMath.ResetIfNonFinite escape hatch on torso + hands
- PhysicsHands.Drive extracted (static) so spikes run the real hand chase
- CollapseSpike: deterministic repro (slow yaw drift across a parked chest, 7/40 NaN on old
code) + solver-stacking scenarios (seated chest in table, two-hand-welded 50 kg anvil,
real PropShop) — 49/49 clean after fix, x3; all other spikes PASS x3
- Failure brief RESOLUTION section; HANDOFF/AGENTS updated
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
