Clothing looks shiny in direct sunlight but not in shadow #97

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opened 2026-09-27 08:22:18 +00:00 by backspace119 · 0 comments

backspace119 commented

2026-09-27 08:22:18 +00:00

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A tester sees their clothes turn shiny in direct sunlight while they look normal in shadow.

Some sun specular disappearing in shadow is correct. The problem is that the sunlit look is far shinier than intended: fabric shouldn't look glossy.

Need from the tester

Screenshot of the same outfit in sun vs. shade, plus the same spot in another viewer (Firestorm/official) for reference.
Whether the clothing is PBR (GLTF material) or legacy (Blinn-Phong specular/normal maps, or no material). Build → Edit → Texture tab shows the material type.
Graphics preset or settings used: shadows, reflection detail, tonemapper, exposure.

Suspects

Legacy specular materials converted to our PBR lit path: wrong environment intensity / glossiness mapping, or a zero/NULL specular map treated as fully glossy.
Default roughness/metallic for faces without a material: they should be rough, non-metal.
Sun specular term not respecting the material's specular color/exponent, or being applied twice (lit FS + another pass).
Reflection probe contribution scaled by the sun shadow term, so shaded areas lose reflections and it reads as "shiny only in sun". If so, the reflection isn't the problem; the unshadowed look is.

Rendering-debug tip: RenderVKDebugView normal/roughness views on the clothing would quickly show whether roughness is near 0.

A tester sees their clothes turn shiny in direct sunlight while they look normal in shadow. Some sun specular disappearing in shadow is correct. The problem is that the sunlit look is far shinier than intended: fabric shouldn't look glossy. **Need from the tester** - Screenshot of the same outfit in sun vs. shade, plus the same spot in another viewer (Firestorm/official) for reference. - Whether the clothing is PBR (GLTF material) or legacy (Blinn-Phong specular/normal maps, or no material). Build → Edit → Texture tab shows the material type. - Graphics preset or settings used: shadows, reflection detail, tonemapper, exposure. **Suspects** - Legacy specular materials converted to our PBR lit path: wrong environment intensity / glossiness mapping, or a zero/NULL specular map treated as fully glossy. - Default roughness/metallic for faces without a material: they should be rough, non-metal. - Sun specular term not respecting the material's specular color/exponent, or being applied twice (lit FS + another pass). - Reflection probe contribution scaled by the sun shadow term, so shaded areas lose reflections and it reads as "shiny only in sun". If so, the reflection isn't the problem; the unshadowed look is. Rendering-debug tip: `RenderVKDebugView` normal/roughness views on the clothing would quickly show whether roughness is near 0.

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2026-09-27 08:22:18 +00:00