Three root causes regressed the Holtburg lifestone since the WB rendering
migration (Phase N.5 retirement amendment, commit dcae2b6, 2026-05-08).
All confirmed via temporary [LIFESTONE-DIAG] instrumentation and visually
verified by the user through the +Acdream test character.
1. **Alpha-test discard** in mesh_modern.frag transparent pass killed
high-α pixels of dat-flagged transparent surfaces. Native AC
transparent surfaces routinely include effectively-opaque pixels —
e.g. the lifestone crystal core (surface 0x080011DE) — that compose
correctly under (SrcAlpha, 1-SrcAlpha) blending. The original N.5
§2 rationale ("high-α belongs in opaque pass") doesn't hold for
surfaces flagged transparent at the dat level: those pixels can't
reach the opaque pass at all. Fix: remove `α >= 0.95 discard` from
the transparent pass, keep `α < 0.05 discard` as a fragment-cost
optimization (skip totally-empty pixels).
2. **Cull state** for the transparent pass was unset by
WbDrawDispatcher after the N.5 retirement amendment deleted
StaticMeshRenderer.cs (which had the Phase 9.2 setup at commit
6f1971a, 2026-04-11). Closed-shell translucents — lifestone crystal,
glow gems — need GL_CULL_FACE + GL_BACK + GL_CCW in the transparent
pass; otherwise back faces composite over front faces in iteration
order under DepthMask(false). Fix: re-establish Phase 9.2's exact
GL state setup at the top of Phase 8.
3. **uDrawIDOffset uniform** was missing from mesh_modern.vert.
gl_DrawIDARB resets to 0 at the start of each
glMultiDrawElementsIndirect call, so the transparent pass — which
begins later in the indirect buffer — was fetching
Batches[0..transparentCount) instead of its actual section at
Batches[opaqueCount..end). The lifestone crystal ended up reading
the FIRST OPAQUE batch's TextureHandle every frame; as the camera
moved and the front-to-back opaque sort reordered which group
landed at BatchData[0], the crystal's apparent texture flickered to
whatever sat first — typically the player character's body parts.
Fix: add `uniform int uDrawIDOffset` to the vertex shader, change
Batches[gl_DrawIDARB] → Batches[uDrawIDOffset + gl_DrawIDARB], and
set the uniform per-pass in WbDrawDispatcher (0 for opaque,
_opaqueDrawCount for transparent). Mirrors WorldBuilder's
BaseObjectRenderManager.cs line 845.
Tests: 1688/1696 passing (8 pre-existing physics/input failures
unchanged). N.5b conformance sentinel 94/94 clean.
Visual: Holtburg lifestone now renders with the spinning blue crystal
correctly composed over the pedestal. Other transparent content (glass,
particle effects, NPC clothing) is unaffected — the same uniform fix
applies globally and is correct for all transparent draws.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Per Phase A.5 spec §4.9.2: ClipMap foliage uses binary alpha-cutoff.
At N₂=12 horizon distance the pixel-stepped silhouettes are visible.
A2C with MSAA 4x produces smooth retail-faithful tree edges.
GL context now requests Samples=4. WbDrawDispatcher's opaque pass
toggles GL_SAMPLE_ALPHA_TO_COVERAGE on/off around the multi-draw
indirect call. mesh_modern.frag's opaque pass now discards only
truly-empty (α<0.05) so the GPU derives sample mask from coverage;
transparent pass boundary logic is unchanged.
MSAA audit: no custom FBOs found — all rendering uses default
framebuffer. Sky/particles/ImGui are all MSAA-compatible.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Code quality review caught four issues:
- Unnecessary GL_ARB_bindless_texture extension in mesh_modern.vert
(vert doesn't use bindless types). Removed; only the frag needs it.
- SSBO binding=1 (BatchBuffer) and UBO binding=1 (SceneLighting) are
in distinct GL namespaces — added a comment in the vert documenting
this so Task 10's bind site doesn't get confused.
- Misleading "0=opaque, 1=transparent" comment expanded to spell out
the full Decision 2 two-pass alpha-test logic and what each discard
threshold protects against.
- BatchData.flags field is reserved; documented that N.5's dispatcher
owns all blend state, with a hook for future shader-side additive.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
New entity shaders for the WB modern rendering path. Modeled on WB's
StaticObjectModern.* but adapted to acdream's lighting model:
- Drops uActiveCells (we cull cells on CPU in WbDrawDispatcher)
- Drops uDrawIDOffset (full passes, no pagination)
- Drops uHighlightColor (deferred to Phase B.4 follow-up; field reserved
in InstanceData struct comment)
- Preserves mesh_instanced's SceneLighting UBO at binding=1 with 8 lights,
fog params, lightning flash, per-channel clamp — full visual identity
vert reads InstanceData[] @ binding=0 indexed by gl_BaseInstanceARB +
gl_InstanceID for the per-entity model matrix; reads BatchData[] @
binding=1 indexed by gl_DrawIDARB for the per-group bindless texture
handle + layer.
frag samples sampler2DArray reconstructed from a uvec2 bindless handle
+ uint layer. uRenderPass uniform picks two-pass alpha-test thresholds:
0 = opaque (discard alpha<0.95), 1 = transparent (discard alpha>=0.95
and alpha<0.05).
Not yet wired to the dispatcher — Task 6 sets up shader load + capability
detection in GameWindow; Task 7-10 rewrite the dispatcher to use SSBO +
glMultiDrawElementsIndirect.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
