When to use this skill

ALWAYS use this skill when the user mentions:

Choosing among built-in mesh materials, map slots (albedo, normal, roughness, metalness, ao, emissive), envMap
Transparency sorting issues, alphaTest, depthWrite, blending modes, side/double-sided rendering
ShaderMaterial / RawShaderMaterial uniforms, includes, and compatibility with lights pipeline
Line, points, sprite materials for vector overlays and particles

IMPORTANT: classic materials vs node-tsl

Need	Skill
Standard PBR with maps, physical clearcoat/sheen	threejs-materials
TSL nodes, `NodeMaterial`, WebGPU-first shading, compute-style graph	threejs-node-tsl
Migrating ShaderMaterial → TSL	threejs-node-tsl (conceptual), keep ShaderMaterial here until cutover

Trigger phrases include:

threejs-materials