User-directed enhancement ('I want the night sky to look very good'):
retail's star layer is one small texture stretched over a 10-poly dome
cap, so stars smear regardless of source-image quality. With the
Atmospheric render pack active, sky.frag now renders the star layer
(GfxObj 0x010015EF, identical in all 20 Dereth day groups) as a fully
procedural sky computed from the view direction: hash-derived stars on
a cube-face grid in three density tiers plus sparse diffraction-spiked
standouts, sized in SCREEN pixels via derivatives so they stay crisp at
any resolution and FOV, over the user-approved 0.4-1.3% cool mottle
(gen_starfield2.py seed 11, approved 2026-08-23). The draw is forced
additive; the day/night fade rides the star layer's existing retail
lighting product so the schedule matches the authored keyframes. Pack
inactive = retail look byte-untouched.
EnhancedNightSkyRuleTests pins the uParamA gate, the exact star-layer
id, the forced-additive draw, and the pack-runtime wiring; sky shader
SPIR-V recompiled and re-pinned. Hermetic App suite green.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Two April stand-ins, neither registered, met at the horizon from altitude as
a hard line between the dome's rim and the fog-coloured clear:
1. sky.frag fogged every non-additive sky layer with a 0.2 floor. Retail's
GameSky::Draw @0x00506FF0 disables fixed-function fog around the whole
sky draw unless an AdminEnvirons fog override is active (SetFFFogEnable(
LScape::m_override_enabled ? 1 : 0)); additive layers stay unfogged via
SetFFFogAlphaDisabled(1) at D3DPolyRender::SetSurface 0x59c882. The sky
pass now sets ApplyFog only for (override active && !additive), with no
floor.
2. WorldRenderFrameBuilder overwrote the authored fog range with one derived
from the streaming window (538..2189 m always). Retail sets FOGSTART/
FOGEND straight from the keyframe's MinWorldFog/MaxWorldFog
(SkyDesc::GetWorldFog @0x00500CE0 -> SetFFFogProperties @0x005A2F70) with
no draw-distance scaling; zfar is a constant 4000 m. The builder now
leaves SceneLightingUbo.Build's values alone; ACDREAM_FOG_START_MULT /
_END_MULT are deleted from RuntimeOptions.
Guards: SkyFogRuleTests (source-level, the sky renderer has no hermetic
harness); sky.frag.spv re-pinned in VulkanShaderManifestTests with the
reason. Research note 2026-04-23-sky-fog.md carries a correction banner.
App hermetic 6,070/0, Core 4,707/0 (Release). Owner look gate owed: night
and rain fog are now retail's shorter authored ranges.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
