Procedural Materials and Shaders

Trigger

Use this skill when the user:

• Wants to create or edit materials from Python rather than the shader editor
• Mentions bpy.data.materials, node_tree, ShaderNodeBsdfPrincipled, inputs[...].default_value
• Needs to generate many materials parametrically (asset libraries, batch import, color variations)
• Asks about EEVEE Next vs Cycles material differences
• Asks about "Layered Textures" or "the new shader system" (see version-correctness section)

Required inputs

• What kind of material: opaque PBR, transparent, emissive, glass, hair, volumetric
• What controls you want exposed: base color, metallic, roughness, IOR, normal map, etc.
• Render engine target: Cycles, EEVEE Next, or both. Most Principled BSDF setups port between the two without changes.

The minimum viable material