Phase B.4c closes#58 (filed during B.4b ship). When a door's
state flips via ACE Door.ActOnUse, the L.2g chain handles the
SetState collision-bit flip but no UpdateMotion handler ever
animated the door visually. Investigation traced the gap to the
spawn-time registration gate at GameWindow.cs:2692 which requires
a multi-frame idle cycle — doors have no idle.
Design: door-specific spawn-time branch that bypasses the gate,
builds an AnimationSequencer, seeds it with Off (closed) or On
(open) cycle based on spawn PhysicsState. ACE Door.cs:43 sets the
same initial state. ~40 LOC in one file. Reuses the existing
AnimationSequencer + per-frame tick + WB renderer pipeline. No
changes downstream.
Discovered during self-review that the per-frame tick at
GameWindow.cs:7691-7697 unconditionally overwrites ae.Entity.MeshRefs
with sequencer-derived transforms; an empty sequencer would collapse
the door to origin. The state-seeded SetCycle at spawn keeps the
sequencer always producing valid frames. Also documented:
ae.Animation = null is safe because the tick's sequencer branch at
line 7497 never reads it (only the legacy slerp else branch does).
Diagnostic tags renamed from phase-named [B.4c] to durable
[door-anim] / [door-cycle] per Opus reviewer feedback on B.4b.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
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