Two independent brightness bugs were compounding to make rain ~6.7×
too bright at the cylinder rim, and clouds full-bright instead of
time-of-day-tinted:
**Fix 1 — Surface.Translucency was never plumbed to the shader.**
Retail's D3DPolyRender::SetSurface at 0x59c767: when the Surface's
Translucent (0x10) bit is set, its translucency float drives per-vertex
alpha (curr_alpha = ftol(0.5 × 255) = 127). ACViewer
(TextureCache.cs:142) and WorldBuilder (ObjectMeshManager.cs:1115) both
encode the same as `opacity = (1 - x)`. acdream read only Surface.Type
and Surface.Luminosity in GfxObjMesh.Build() — Surface.Translucency
(the float) was never read, never stored, never reached the shader.
For the rain Surface 0x080000C5 (Translucency=0.5) this meant rain
streaks were at full alpha=1.0 instead of 0.5 — 2× brighter than retail
under the (SrcAlpha, One) blend.
Plumbed end-to-end:
GfxObjSubMesh.SurfTranslucency (init float, default 0)
GfxObjMesh.Build() reads surface.Translucency next to .Luminosity
SubMeshGpu.SurfTranslucency carries it to draw time
SkyRenderer.RenderPass writes uniform `uSurfTranslucency`
sky.frag final alpha: a = sampled.a × (1 - uTransparency) ×
(1 - uSurfTranslucency)
Bonus reach: cloud surface 0x08000023 has Translucency=0.25 → clouds
also dimmed by 25%, more retail-faithful overall.
**Fix 2 — Emissive default was 1.0 instead of the surface's actual Luminosity.**
The sky shader's `effEmissive = (luminosity > 0) ? luminosity : sub.SurfLuminosity`
fallback never fired because the local `luminosity` defaulted to 1f (always
> 0). Every sky mesh got effEmissive=1.0, saturating vTint to white before
the alpha blend. The comment claimed the fallback was active; the code
disagreed.
Empirical sky-surface LUMINOUS audit (RainMeshProbe a6e7108) found that
NO Dereth sky surface carries the SurfaceType.Luminous flag (0x40) —
the previous code comment that did was wrong. The differentiator is
purely the Surface.Luminosity FLOAT:
dome/sun/moon: Lum=1.0 → vTint saturates → texture passthrough
stars/clouds: Lum=0.0 → vTint = ambient + sun·N·L → time-of-day tint
rain: Lum=0.1484 → faint emissive baseline + lit additions
Refactored:
replaceLuminosity = NaN sentinel for "no replace override"
rep.Luminosity > 0 → set replaceLuminosity to override value
rep.MaxBright > 0 → cap replaceLuminosity at MaxBright
effEmissive = NaN ? sub.SurfLuminosity : replaceLuminosity
Dead uniform `uLuminosity` removed from sky.frag and SkyRenderer SetFloat
call — the redundant multiply was already commented-out earlier this
year (would have double-dimmed clouds), and the uniform value was unused
in the fragment.
Visual verification (Holtburg, live ACE, Rainy DG forced and natural
LCG-picked): rain rim is no longer visible; cloud direction matches
retail when the same DayGroup is active; sky lighting transitions through
day cycle with appropriate time-of-day tint on stars/clouds.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Bug B in docs/research/2026-04-26-sky-investigation-handoff.md: stars
rendered as a small square in one corner of the sky instead of stretching
across the dome.
Root cause: the wrap-mode heuristic at SkyRenderer.cs:234-237 was
"GL_CLAMP_TO_EDGE unless TexVelocity != 0". That heuristic was tuned to
fix a separate symptom (the outer dome 0x010015EE/F0/F1/F2 shows
wall-seam bleed under GL_REPEAT because of bilinear-filter sampling at
texel boundaries). But it misclassified any *static* sky object whose
mesh UVs are deliberately authored outside [0,1] to tile the texture
across the geometry.
The smoking gun: GfxObj 0x010015EF is OI-1 in EVERY DayGroup (always
loaded), has TexVelocity = 0 (no scrolling), and authors UVs in
[0.398, 4.602] (texture tiles ~4× across each face). Under
CLAMP_TO_EDGE the bulk of the inner dome sampled the texture's edge
texels; only the small region where UVs happened to fall in [0,1]
showed actual texture content. Hence "a square in one corner".
Fix:
* GfxObjMesh.Build() now scans the resulting per-vertex UVs and sets
GfxObjSubMesh.NeedsUvRepeat true when any component lies outside
[0,1]. Mesh-time scan, not draw-time guess.
* SubMeshGpu carries the flag through to draw time.
* SkyRenderer uses `sub.NeedsUvRepeat || obj.TexVelocity != 0` to
decide REPEAT vs CLAMP_TO_EDGE. The dome (UVs in [0,1]) keeps
CLAMP — no seam regression. The inner star/sky layer 0x010015EF
(UVs outside [0,1]) gets REPEAT — texture tiles across the dome.
Cloud meshes (UVs outside [0,1] AND non-zero TexVelocity) keep
REPEAT via either branch.
Probe-driven: tools/StarsProbe (committed in 991fb9a) dumps every
SkyObject's geometry + UVs and flags meshes whose UV range exceeds
[0,1]. Run `dotnet run --project tools/StarsProbe -c Release` to
re-derive.
Verified visually by user against the live ACE server in Holtburg —
stars now stretch across the night sky instead of appearing as a
square in one corner. Build green, dotnet test 1222 pass.
Note: this is functionally retail-equivalent for the reported bug but
not the exact retail mechanism. Retail's GameSky::Draw at 0x00506ff0
relies on D3D's global default D3DTADDRESS_WRAP (i.e. REPEAT
everywhere). True retail-faithfulness would require investigating why
our pipeline shows seams on the dome under REPEAT (likely a bilinear
filter / non-seamless texture detail). The data-driven approach taken
here preserves working dome behavior while fixing the broken star
behavior.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Phase 2 of the sky port. Empirically confirmed from the Phase 1 dump
(ACDREAM_DUMP_SKY=1 on the live Dereth region): retail distinguishes
self-illuminated sky meshes from lit ones by the `Surface.Luminosity`
FLOAT field (0..1), NOT by the `SurfaceType.Luminous` flag bit (none of
Dereth's sky meshes have the flag set).
Observed values on the 4 currently-visible sky GfxObjs:
GfxObj 0x010015EE (dome, 4 surfaces) Luminosity = 1.0
GfxObj 0x010015EF (upper cloud) Luminosity = 0.0
GfxObj 0x01004C36 (lower drift cloud) Luminosity = 0.0
GfxObj 0x01001348 (sun/moon additive) Luminosity = 1.0
Retail uses this as an emissive coefficient in the per-vertex lighting
formula (decompiled chunk_00500000.c:7535 FUN_00508010 + chunk_00530000.c
AdjustPlanes per-vertex math):
tint = clamp(vec3(Luminosity) + AmbColor*AmbBright
+ max(dot(N, -sunDir), 0) * DirColor*DirBright,
0.0, 1.0)
fragment = texture * tint
When Luminosity=1.0 the clamp saturates → full texture brightness
regardless of time of day (dome gradient preserved; sun/moon always
bright). When Luminosity=0.0 only the ambient + diffuse term drives the
tint, so clouds pick up the time-of-day ambient (purple at midnight
per AmbColor=(200,100,255)×AmbBright=0.4 ≈ (0.31,0.16,0.40); warm tan
at dusk; pale-cool at noon).
Also empirically confirmed: raw SkyObjectReplace Transparent/Luminosity
/MaxBright are in 0..100 percent range (observed 11, 15, 22, 66, 100,
and -1 sentinel). The `/100` divide in SkyDescLoader (eeae83a) is
retail-correct; `_DAT_007a1870` in the decompile must be 0.01f.
Code changes:
- src/AcDream.Core/Meshing/GfxObjSubMesh.cs: new `Luminosity` field on
the per-submesh record (0..1, defaults to 0 for non-sky meshes).
- src/AcDream.Core/Meshing/GfxObjMesh.cs: pull Surface.Luminosity when
building submeshes (alongside existing Translucency capture).
- src/AcDream.App/Rendering/Sky/SkyRenderer.cs:
- SubMeshGpu gains SurfLuminosity, propagated from GfxObjSubMesh.
- Render() pushes uAmbientColor/uSunColor/uSunDir once per frame from
the interpolated keyframe; uEmissive once per submesh.
- uTint uniform removed (replaced by the vTint varying computed in
the vertex shader).
- src/AcDream.App/Rendering/Shaders/sky.vert: computes vTint per-vertex
using the retail AdjustPlanes formula.
- src/AcDream.App/Rendering/Shaders/sky.frag: consumes vTint, drops
uTint uniform. uLuminosity (the per-keyframe SkyObjectReplace
override) still applied as a final scalar multiply.
Expected visual difference from Phase 1 baseline:
- Dome gradient: IDENTICAL (Luminosity=1 saturates).
- Sun / moon: IDENTICAL (Luminosity=1 saturates, additive blend).
- Clouds: now tinted by time of day. Midnight → purple haze. Noon →
pale cool. Dusk → warm tan.
Open questions (unchanged from Phase 1 doc):
- Does the 15s LightTickSize throttling need porting? Phase 3.
- Does FUN_00532440 (AdjustPlanes per-cell terrain relight) need
porting for non-sky geometry to follow the sky? Phase 3.
Build + 717 tests green.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Four fixes from the ACME StaticObjectManager cross-reference:
1. GfxObjMesh: normalize vertex normals (1d). Dat normals may not be
unit-length; without normalization, lighting is wrong per-vertex.
2. SetupMesh: add third-fallback placement frame (2a). If neither
Resting nor Default exists, use the first available frame from
PlacementFrames. Matches ACME's GetDefaultPlacementFrame.
3. SceneryGenerator: building cell exclusion (4d). Compute which
terrain vertices have buildings (from LandBlockInfo.Objects +
Buildings), skip scenery spawns in those cells. Prevents trees
from spawning inside building footprints.
4. SceneryGenerator: slope filter (4e). Compute terrain normal Z at
each displaced position and check against ObjectDesc.MinSlope /
MaxSlope bounds. Prevents trees from spawning on cliff faces.
Also confirmed 4f (scenery Z=0) is NOT a bug — GameWindow's hydrator
lifts scenery to terrain Z at line 1213. The Z=0 in SceneryGenerator
is a placeholder correctly overridden at render time.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
The lifestone (and likely any weenie with closed shells using NoPos /
Negative / Both stippling) rendered with visible holes where you could
see inside it — confirmed via the user's "see into it" description.
Root cause: GfxObjMesh.Build skipped any polygon whose PosSurface was
out of range, which is exactly what a NoPos-stippled or
negative-only polygon looks like. Backface culling isn't involved
(acdream has it disabled); we were simply dropping triangles.
Ported the pos/neg emission rule from
references/WorldBuilder/Chorizite.OpenGLSDLBackend/Lib/
ObjectMeshManager.cs (lines 955-971 and 1510-1577):
pos side: emit when !Stippling.NoPos and PosSurface is valid
neg side: emit when Stippling.Negative, Stippling.Both, OR
(!Stippling.NoNeg && SidesType == CullMode.Clockwise)
The "Clockwise CullMode means NegUVIndices are on the wire" rule is
non-obvious but matches how Polygon.Unpack reads NegUVIndices, so
any closed mesh relying on that convention now renders correctly.
Neg-side triangles get the reversed fan winding and a negated vertex
normal. With culling off the winding only matters for lighting
consistency, but keeping the semantics right future-proofs the
fix if we ever enable back-face culling for a perf pass. The
dedup cache is keyed by (posIdx, uvIdx, isNeg) so the same vertex
can carry different normals on the pos and neg sides.
Pos-side winding is preserved at the original (0, i, i+1) order so
the existing single-triangle and fan-triangulation tests still pass
— neg side uses (i+1, i, 0), which is the same shape mirrored.
194 tests green.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
Server sends UpdateMotion whenever an entity's motion state changes:
NPCs starting a walk cycle, creatures switching to a combat stance,
doors opening, a player waving, etc. Phase 6.1-6.4 already handles
rendering different (stance, forward-command) pairs for the INITIAL
CreateObject, but without this message NPCs freeze in whatever pose
they spawned with and never transition to walking/fighting.
Added UpdateMotion.TryParse with the same ServerMotionState the
CreateObject path uses, reached via a slightly different outer
layout (guid + instance seq + header'd MovementData; the MovementData
starts with the 8-byte sequence/autonomous header this time rather
than being preceded by a length field). Only the (stance, forward-
command) pair is extracted — same subset CreateObject grabs.
WorldSession dispatches MotionUpdated(guid, state) when a 0xF74C
body parses successfully. The App-side wiring (guid→entity lookup
and AnimatedEntity cycle swap) is intentionally deferred to a
separate commit because it touches GameWindow which is currently
being edited by the Phase 9.1 translucent-pass work.
89 Core.Net tests (was 83, +6 for UpdateMotion coverage).
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
