Campaign V slice V6e, last of three. Sky was the hardest of the four pairs
because it was the only one that still worked the way a 2004 shader works: a
dozen loose uniforms pushed one glUniform call at a time, and a texture bound to
unit 0 with a sampler object chosen per submesh. Vulkan GLSL has neither a
default uniform block nor a way to declare a bare sampler, so both had to move —
and the second one had a sting in it.
The uniforms go into a `SkyParams` std140 block at uniform binding 4, the new
pre-authorized constant in GpuBindingModel (1, 2 and 3 are SceneLighting, the
terrain clip block and terrain tiling; the contract test now proves the three
constants and that literal 2 do not collide). Three matrices are 192 bytes on
their own, so the 96-byte push-constant block was never in the running. The
block's member order IS its layout: std140 aligns a vec3 to 16 bytes while using
12, so each of the three lighting vectors is followed by the float that rides in
its pad word, which is why colours and per-surface scalars interleave rather
than grouping by meaning. SkyParamsLayoutTests asserts all twelve offsets and
the 256-byte size, because getting one member wrong would read the sun direction
as a colour with no compile error, no link error and no GL error to say so.
The texture is the interesting half. sky.frag now reads through the shared table
(ACDREAM_SAMPLE_2D), and a bindless handle BAKES its sampler — so the
per-submesh Repeat-versus-ClampToEdge choice, which used to be a glBindSampler
on unit 0, becomes which slot the submesh asks for. SkyRenderer interns one
handle per (texture, wrap) pair, exactly as ManagedGLTextureArray has done since
the world path went bindless, and exactly the shape Vulkan's table has, where an
entry is a combined image sampler. Same two SamplerCache objects, same wrap
behaviour, consulted once at interning instead of once per draw. A pleasant
consequence: the sky no longer touches texture unit 0, so the load-bearing
`BindSampler(0, 0)` restore at the end of the pass — there because the binding
was global state that would otherwise force ClampToEdge on the next renderer —
has nothing left to undo and is gone.
Gates. Release build clean; App tests 4,072 passed / 3 skipped (4,057 baseline,
plus the sentinel guard from the previous commit and fourteen sky-layout
assertions). Offline pixel gate against 95f8c25f: 18 px of 563,200 compared
(3.20e-05), inside the documented 15–23 px band.
That gate masks the sky for determinism, so it proves nothing about this commit
and the sky renderer has no automated pixel coverage at all. What was done
instead: a base-versus-head offline capture at ALL SEVEN day groups, built by
stashing the change and rebuilding so the two runs differ only in this commit.
Every pair matches in gradient, cloud sheet, horizon band and fog — including
day group 2's salmon cloud band and day group 6's green one, which between them
exercise texture sampling, per-vertex tint, blend mode and fog. Then 3/3
RENDERED on the desktop-witness repeat-connected gate.
That bounds the risk; it does not close it. The offline camera is fixed and
looks down, so a thin band of dome is all it ever sees: the sun and moon
(additive, high) and the rain cylinder (the one sky mesh that surrounds the
camera, and the one whose REPEAT wrap is most visible) remain unproven. Recorded
as user-gate debt in §5.1 alongside V2c's and V4e's particles — check it by
standing outside at dawn or dusk, and by standing in rain.
Manifest: 8/9 pairs compile. `terrain_modern` is the last production pair, and
it is blocked on V4d's content rather than on dialect — details in §5.5's slice
table. `mesh` has no consumer.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
The sky + weather (rain cylinder) are retail's LScape — 'the outside seen through the exit portal.' Retail PView::DrawCells (pseudo_c:432709) draws LScape clipped to the OutsideView when outside_view.view_count>0, then does a conditional Z-buffer-ONLY clear (432731) before the indoor cells. acdream now does the same:
- sky.vert writes gl_ClipDistance against the SAME binding=2 TerrainClip UBO the terrain reads. The OutsideView planes are screen-space (NDC) half-spaces encoded as clip-space planes (nx,ny,0,dw); the test dot(plane,gl_Position)>=0 reduces after perspective divide to nx*ndcX+ny*ndcY+dw>=0 — projection-INDEPENDENT — so the same plane set clips the sky EXACTLY despite its separate dome projection. count==0 (outdoor) → all distances +1 → full-screen, bit-identical. Lighting/fog math untouched.
- GameWindow: relocated the sky pre-scene + weather post-scene draws to their retail LScape positions, each in a local 8-plane clip bracket so sky.vert confines them to the doorway indoors / full-screen outdoors. Added the conditional doorway depth-ONLY Z-clear (no color → no blue hole), scissored to the OutsideView AABB. drawSkyThisFrame = seen_outside policy AND (outdoor OR exit-portal-in-view) — a sealed interior with no exit portal in view draws no sky (kills the full-screen-sky interim regression). Sky pre/post particle passes (particle.vert has no gl_ClipDistance) scissored to the doorway bbox.
- ClipFrameAssembly gains HasOutsideView + OutsideViewNdcAabb (the doorway NDC AABB, computed for BOTH Planes and Scissor terrain modes — unlike TerrainScissorNdcAabb which is Scissor-only).
- The pre-login goto SkipWorldGeometry moved BELOW the sky draw so the live sky still renders during the EnterWorld handshake (clipAssembly is null/no-clip pre-login → full-screen).
Build green; App tests 160/160. Stage 4 tests + verify-annotations follow.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Ports retail's ParticleEmitterInfo / Particle::Init / Particle::Update
(0x005170d0..0x0051d400) and PhysicsScript runtime to a C# data-layer
plus a Silk.NET billboard renderer. Sky-PES path is debug-only behind
ACDREAM_ENABLE_SKY_PES because named-retail decomp confirms GameSky
copies SkyObject.pes_id but never reads it (CreateDeletePhysicsObjects
0x005073c0, MakeObject 0x00506ee0, UseTime 0x005075b0).
Post-review fixes folded into this commit:
H1: AttachLocal (is_parent_local=1) follows live parent each frame.
ParticleSystem.UpdateEmitterAnchor + ParticleHookSink.UpdateEntityAnchor
let the owning subsystem refresh AnchorPos every tick — matches
ParticleEmitter::UpdateParticles 0x0051d2d4 which re-reads the live
parent frame when is_parent_local != 0. Drops the renderer-side
cameraOffset hack that only worked when the parent was the camera.
H3: Strip the long stale comment in GfxObjMesh.cs that contradicted the
retail-faithful (1 - translucency) opacity formula. The code was
right; the comment was a leftover from an earlier hypothesis and
would have invited a wrong "fix".
M1: SkyRenderer tracks textures whose wrap mode it set to ClampToEdge
and restores them to Repeat at end-of-pass, so non-sky renderers
that share the GL handle can't silently inherit clamped wrap state.
M2: Post-scene Z-offset (-120m) only fires when the SkyObject is
weather-flagged AND bit 0x08 is clear, matching retail
GameSky::UpdatePosition 0x00506dd0. The old code applied it to
every post-scene object — a no-op today (every Dereth post-scene
entry happens to be weather-flagged) but a future post-scene-only
sun rim would have been pushed below the camera.
M4: ParticleSystem.EmitterDied event lets ParticleHookSink prune dead
handles from the per-entity tracking dictionaries, fixing a slow
leak where naturally-expired emitters' handles stayed in the
ConcurrentBag forever during long sessions.
M5: SkyPesEntityId moves the post-scene flag bit to 0x08000000 so it
can't ever overlap the object-index range. Synthetic IDs stay in
the reserved 0xFxxxxxxx space.
New tests (ParticleSystemTests + ParticleHookSinkTests):
- UpdateEmitterAnchor_AttachLocal_ParticlePositionFollowsLiveAnchor
- UpdateEmitterAnchor_AttachLocalCleared_ParticleFrozenAtSpawnOrigin
- EmitterDied_FiresOncePerHandle_AfterAllParticlesExpire
- Birthrate_PerSec_EmitsOnePerTickWhenIntervalElapsed (retail-faithful
single-emit-per-frame behavior)
- UpdateEntityAnchor_WithAttachLocal_MovesParticleToLiveAnchor
- EmitterDied_PrunesPerEntityHandleTracking
dotnet build green, dotnet test green: 695 / 393 / 243 = 1331 passed
(up from 1325).
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Retail applies linear vertex fog with 3D range distance
(D3DRS_FOGVERTEXMODE=3=LINEAR, D3DRS_RANGEFOGENABLE=1,
D3DRS_FOGTABLEMODE=0=NONE) to ALL mesh draws including sky. Only
FOGCOLOR / FOGSTART / FOGEND are lerped per keyframe; the mode flags
are init-only.
Verified in `docs/research/2026-04-23-sky-fog.md`:
- chunk_005A0000.c:3361-3389 device-init sets the modes.
- Sky meshes render at world origin (translation zeroed, rotation-
only) with intrinsic mesh radii in the thousands of meters
(WorldBuilder's SkyboxRenderManager.cs:247 comment confirms).
- With keyframe MaxWorldFog = 2400m, the dome saturates to
WorldFogColor at its horizon band. THAT is retail's dusk/dawn
horizon-glow mechanism.
Port:
`sky.vert` now computes the vertex fog factor:
worldPos = uModel × aPos (camera-centered since view translation=0)
dist = length(worldPos.xyz)
fogFactor = clamp((fogEnd - dist) / (fogEnd - fogStart), 0, 1)
— outputs as varying vFogFactor. 1.0 means no fog contribution,
0.0 means full fog color.
`sky.frag` applies the mix BEFORE the lightning-flash bump:
rgb = mix(uFogColor.rgb, rgb, vFogFactor)
Uses the existing SceneLighting UBO's uFogParams (x=start, y=end,
z=flash, w=mode) and uFogColor — no new uniforms, no C# change.
Expected visual:
- Dome at dawn/dusk: horizon band blends toward keyframe fogColor
(warm orange at sunset, cool blue at dawn), matching retail's
sky/fog coupling.
- Close sky objects (sun disk at typical mesh radius): unaffected
since dist < fogStart.
- Clouds at intermediate distance: partial fog blend, subtly
muting their saturation with distance.
Note on lightning: the flash channel (uFogParams.z) stays wired but
is currently always 0 because no code drives it. Agent #5 is
researching retail's real lightning mechanism (PlayScript / SetLight
PhysicsScript / other). This commit does not attempt to port it.
Build + 733 tests green.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
After Phase 4 landed the per-vertex lighting formula, user observed
acdream was still "a bit too bright" vs retail. Root cause:
- My Phase 4 shader deliberately left vTint unclamped so D3D-style
overbright contributions to emissive meshes (dome has Emissive=1 → lit
could reach 2.0 with ambient + sun) would clamp naturally at the
framebuffer.
- But the frag cap was 1.2 (leaving "headroom for lightning flash"),
letting dome vertices run 20% hotter than retail's per-channel 1.0.
Retail's D3D fixed-function pipeline clamps vertex lit colour at
D3DRS_COLORCLAMP=1 (default) BEFORE texture modulation. We now match:
- Clamp `vTint = clamp(lit, 0, 1)` in sky.vert so the saturate happens
at the vertex stage, exactly like D3D.
- Drop normal-frame frag cap from 1.2 → 1.0 (the 3.0 flash relaxation
stays so lightning strobes still visibly blow out).
Expected visual:
- Dome: identical appearance (was clamping to framebuffer 1.0 anyway),
but pure retail-spec rendering so no sneaky 20% headroom.
- Clouds: unchanged (already < 1.0 at morning Rainy keyframe).
- Fragment flash during storm: unchanged — cap relaxes to 3.0 on flash.
Build + 733 tests green.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Re-enables the Phase 2 lighting formula that was reverted in Phase 3b
due to a "blue-green-yellow sweep" across clouds. Root cause of that
earlier regression was NOT the formula — it was that we rolled the
wrong DayGroup (Sunny when retail was Cloudy), producing a sharp warm
sun against a sky that should have been rendered with diffuse
overcast light. After Phase 3g pinned the LCG multiplier to 360
(DaysPerYear) so retail + acdream agree on DayGroup, the same
per-vertex formula now faithfully reproduces retail's visuals.
The formula is verified in decompile agent Q2+Q4+Q6 results,
`docs/research/2026-04-23-sky-material-state.md`:
D3DRS_LIGHTING = ON (FUN_0059da60:10648)
D3DRS_AMBIENT = 0 (never written after init)
Material.Emissive = (Luminosity, Luminosity, Luminosity, 1)
Material.Ambient/Diffuse = defaults (≈1,1,1,1) for non-luminous
light.Ambient = keyframe AmbColor × AmbBright (via SetDirectionalLight)
light.Diffuse = keyframe DirColor × DirBright
Fixed-function lighting per vertex:
lit = Emissive + Ambient × lightAmbient + Diffuse × lightDiffuse × max(N·L, 0)
= Surface.Luminosity + AmbColor×AmbBright + DirColor×DirBright × max(N·L, 0)
Fragment: texture × lit × SkyObjectReplace.Luminosity.
Expected visual:
- Dome (Surface.Luminosity=1): `lit = 1 + amb + diff·N·L` saturates to 1
→ texture passthrough, baked gradient preserved.
- Clouds (Surface.Luminosity=0): `lit = 0 + amb + diff·N·L`
→ purple haze at night (ambient dominates, sun below horizon);
→ warm tan at dusk (ambient + warm sun on west-facing vertices);
→ pale cool gray at noon (ambient + white sun from above).
- Sun/moon (SurfaceType.Additive, Luminosity=1): same as dome +
additive blend — stays bright regardless.
The shader uniforms (uAmbientColor, uSunColor, uSunDir, uEmissive)
were already wired in the C# renderer from Phase 2; Phase 3b just
stopped using them in the shader. This commit re-activates them.
No clamp at the vertex — retail's D3D lighting allows Emissive+sum
to exceed 1, relies on the framebuffer per-channel saturation. We
keep the 1.2 ceiling in the frag (for lightning flash overbright
headroom) consistent with that convention.
No fog yet (Q1 confirmed retail leaves fog enabled for sky; will add
in a follow-up if horizon looks too bright).
Build + 733 tests green.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Phase 2 added a per-vertex lighting path to the sky shader based on the
Phase 1 dump showing dome surfaces with Luminosity=1.0 and cloud
surfaces with Luminosity=0.0. Live visual verification vs retail at
MorntideAndHalf (dayFraction=0.48, user-observed 2026-04-23) disproved
the hypothesis:
retail: clean blue sky + white clouds
acdream: blue-green-yellow sky sweep + greyish clouds
The "sweep" is exactly the signature of per-vertex `diffuse × sunColor`
where sunColor=(250,215,151) warm gold at ~63° east: the west-facing
cloud faces get the gold tint, east-facing stay cool, and interpolation
across the mesh produces the color sweep. Retail's clean white clouds
at the same time of day means retail is NOT applying per-vertex lighting
to sky meshes.
Revised model (unlit + SkyObjectReplace modulation):
fragment.rgb = texture.rgb * uLuminosity
fragment.a = texture.a * (1 - uTransparency)
The "purple haze night / warm dusk" effect users describe from retail
comes from SkyObjectReplace per-keyframe Luminosity dimming + Transparent
fading, NOT from a shader ambient multiply. At midnight, for example,
Replace[0] dims the dome to 11% (Luminosity_raw=11) and Replace[2]
fully hides the drifting cloud (Transparent_raw=100) — so the camera
sees the dome texture at 11% × baked gradient colors, and any purple
the user perceives is baked into the dome texture's night gradient.
The retail-authoritative Surface.Luminosity flag probably feeds a
separate render path (material system? D3D emissive vs diffuse
coefficients?) that is NOT per-vertex GL lighting. A future phase can
revive it if the decompile hunt for the DayGroup selection algorithm
surfaces it.
Code change: sky.vert + sky.frag only. The C# renderer still pushes
uAmbientColor/uSunColor/uSunDir/uEmissive uniforms — they are declared
in the shaders but unused in Phase 3b. No renderer change needed; these
uniforms cost nothing and keep the port-forward path open.
Build + 717 tests green.
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>
Wire the existing LightManager + WorldTimeService state into visible
rendering. Every draw call (terrain, static mesh, instanced mesh, sky)
now shares one SceneLighting UBO at binding=1 carrying:
- 8 Light slots (Directional / Point / Spot, retail hard-cutoff)
- Ambient RGB + active light count
- Fog start/end/mode + color + lightning flash scalar
- Camera world position + day fraction
The CPU side (SceneLightingUbo in Core.Lighting) is a POD struct that
gets BufferSubData'd once per frame from GameWindow.OnRender. Shaders
read the block via `layout(std140, binding = 1) uniform SceneLighting`
— no per-program uniform uploads.
Shader changes:
- mesh.frag + mesh_instanced.frag accumulate 8 dynamic lights per
fragment using the retail no-attenuation hard-cutoff model
(r13 §10.2 / §13.1). Sun reads slot 0; spots use hard cos-cone test.
Additive lightning flash + linear fog layered on top. Saturate
clamps per-channel to 1.0.
- terrain.vert bakes AdjustPlanes sun+ambient per vertex using the
retail MIN_FACTOR = 0.08 ambient floor (r13 §7). terrain.frag adds
fog + flash on top of the baked vertex color.
- mesh.vert + mesh_instanced.vert emit vWorldPos so the fragment
stage can do per-pixel lighting against world-space positions.
- New sky.vert / sky.frag pair — unlit, scroll-UV, camera-centered,
with its own 0.1..1e6 far plane. Ports WorldBuilder's skybox.
SkyRenderer (new file in App/Rendering/Sky/) ports WorldBuilder's
SkyboxRenderManager verbatim for the C# idiom: zeroed view translation,
dedicated projection, depth mask off, iterate each visible SkyObject
in the day group, apply arc transform (Z rot for heading + Y rot for
arc sweep), feed TexVelocityX/Y as a scrolling UV offset, apply
per-keyframe SkyObjectReplace overrides (mesh swap + transparency +
luminosity) for overcast / dusk cloud variants.
GameWindow integration:
- OnLoad parses Region (0x13000000) into LoadedSkyDesc and hot-swaps
WorldTime's provider to the dat-accurate keyframes. Seeds to noon
for offline rendering. Creates the SceneLightingUboBinding and the
SkyRenderer.
- OnRender: set clear color from atmosphere fog, tick WeatherSystem,
spawn/stop rain/snow camera-local emitters on kind change, feed
sun to LightManager (zero intensity indoors — r13 §13.7), tick
LightManager against viewer pos, build + upload the UBO, draw
sky before terrain, draw terrain + static + instanced using the
shared UBO.
5 new UBO packing tests (struct sizes, slot population, 8-light cap,
directional slot 0).
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Erik