WebGLRenderer: Force flat shading for geometries without normals.

[mrdoob]

Description

Previously, geometries without normals would render black with materials that require normals for lighting calculations. Users had to manually set material.flatShading = true or call geometry.computeVertexNormals() as a workaround.

The renderer now detects this case and automatically uses flat shading, which computes normals from screen-space derivatives in the fragment shader.

[github-actions]

📦 Bundle size

Full ESM build, minified and gzipped.

	Before	After	Diff
WebGL	356.57 84.67	356.71 84.7	+142 B +34 B
WebGPU	621.78 172.66	621.78 172.66	+0 B +0 B
WebGPU Nodes	620.38 172.43	620.38 172.43	+0 B +0 B

🌳 Bundle size after tree-shaking

Minimal build including a renderer, camera, empty scene, and dependencies.

	Before	After	Diff
WebGL	489.35 119.68	489.5 119.71	+142 B +34 B
WebGPU	692.75 187.97	692.75 187.97	+0 B +0 B
WebGPU Nodes	642.41 175.15	642.41 175.15	+0 B +0 B

[mrdoob]

@Mugen87 @sunag

I've tried to get Claude to port this change to WebGPURenderer but it can't figured it out. Can you give it a go?

In order to repro:

• Set the renderer to WebGPU
• Drop abb_irb52_7_120.dae
• The model will appear black
• Change the renderer to WebGL
• The model will be lit

[supervitas]

@mrdoob It was okay. Now i cant use my custom oct-encoded normals. Because its vec2 attribute, and cant be aligned for vec3 normal.

[mrdoob]

Can you create a jsfiddle that shows what you're doing?

[supervitas]

@mrdoob Okay, nevermind, since i can override parameter flatShading which is comming in onBeforeCompile thats still works