[FIX] Convert sRGB colors to linear when writing glTF#8267
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willeastcott merged 7 commits intomainfrom Dec 19, 2025
Merged
[FIX] Convert sRGB colors to linear when writing glTF#8267willeastcott merged 7 commits intomainfrom
willeastcott merged 7 commits intomainfrom
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Pull request overview
This PR fixes a critical bug in the glTF exporter where material colors were not being converted from sRGB to linear color space, causing colors to become progressively brighter with each import/export cycle. It also refactors the parser to use cleaner Color API methods for consistency.
Key Changes:
- Added proper color space conversion in the glTF exporter using
Color.linear()forbaseColorFactorandemissiveFactor - Refactored the glTF parser to replace manual
Math.pow(x, 1/2.2)calls with the cleanerColor.gamma()method - Established symmetric operations:
Color.gamma()for import (linear → sRGB) andColor.linear()for export (sRGB → linear)
Reviewed changes
Copilot reviewed 2 out of 2 changed files in this pull request and generated no comments.
| File | Description |
|---|---|
src/extras/exporters/gltf-exporter.js |
Added sRGB to linear color space conversion when writing baseColorFactor and emissiveFactor to glTF, fixing the export color space bug |
src/framework/parsers/glb-parser.js |
Refactored linear to sRGB conversions to use Color.gamma() method instead of manual Math.pow() calls for improved code clarity and consistency across all material color factors |
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willeastcott
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mvaligursky
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Dec 19, 2025
* [FIX] Convert linear colors to sRGB when writing glTF * Drop comments * Tweak exporter * Use clone * Use array destructuring
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This PR fixes the color space handling in the glTF exporter and refactors the importer for consistency.
Problem
The glTF exporter was writing material colors (
baseColorFactor,emissiveFactor) directly from the engine's sRGB color space without converting to linear space as required by the glTF specification. This caused colors to become brighter on each import/export cycle.Changes
Exporter (
gltf-exporter.js):Color.linear()conversion when writingbaseColorFactorandemissiveFactorto convert from engine sRGB to glTF linear spaceParser (
glb-parser.js):Math.pow(x, 1/2.2)calls to useColor.gamma()method for:baseColorFactoremissiveFactordiffuseFactor(KHR_materials_pbrSpecularGlossiness)specularFactor(KHR_materials_pbrSpecularGlossiness)specularColorFactor(KHR_materials_specular)sheenColorFactor(KHR_materials_sheen)attenuationColor(KHR_materials_volume)Result
Import and export now use symmetric operations:
Color.gamma()- linear (glTF) → sRGB (engine)Color.linear()- sRGB (engine) → linear (glTF)Material colors are now preserved correctly through import/export roundtrips.
Checklist