Lands the fading-secret-door feature and fixes the door "flip-back" that
surfaced while testing it.
#188 — fading-wall doors (e.g. "Pedestal Weak Spot") fade their wall part
out via TransparentPartHook instead of swinging:
- TranslucencyHookSink consumes TransparentPartHook -> TranslucencyFadeManager
(per-(entity,part) linear translucency ramp; holds at End frame).
- WbDrawDispatcher: new per-instance alpha SSBO (binding 7); ClassifyBatches
takes opacityMultiplier (1 - translucency, per CMaterial::SetTranslucencySimple
0x005396f0) forcing AlphaBlend; fully-invisible parts skipped.
- mesh_modern.vert/.frag: binding-7 InstanceAlphaBuf -> vOpacityMultiplier ->
FragColor.a *= vOpacityMultiplier.
- Register AP-89: the fade multiplies sampled texture alpha, not a separate
D3D9 material alpha channel (observably identical for texture-alpha==1 surfaces).
Door flip-back fix (affected BOTH #188 fading walls AND #187 sliding doors): a
door/wall that finished opening holds a single unchanging frame, so the
uncommitted IsEntityCurrentlyMoving cache-bypass narrowing dropped it onto the
Tier-1 static cache -- which only remembers the REST pose + opacity 1.0 --
snapping it visually shut/opaque while physics stayed open. Reverted that
narrowing: every Sequencer entity stays on the per-frame path (live pose + live
fade opacity), the known-good pre-optimization behavior. The per-frame CPU cost
that narrowing chased was a Debug-build artifact -- Release is GPU-bound
(~200 fps in Sawato, measured), so the unconditional add is free where it
matters. Left a code comment barring re-introduction.
Tests: full Core suite green (2649 passed, 2 skipped). Live visual gate PASSED --
both fading-wall and sliding doors hold open.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>