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