MCP backend

Use when: Any material assignment, PBR setup, shader work, or look-dev request in Blender. Before the first Blender call, read ../text-to-blender/references/mcp-backends.md. Prefer official MCP for shared capabilities; preserve the selected backend for the whole task. Tool names in recipes are client/legacy examples: map them through that reference and its agent-host guide.

Blender Materials

Apply physically-based materials to objects. Use only Principled BSDF — it's the only shader that exports cleanly to glTF and matches what other DCC tools expect.

The metallic switch — never an in-between

The single most-important rule: Metallic is a switch, not a slider. Set it to 0.0 (dielectric: plastic, wood, glass, skin) or 1.0 (metal: steel, gold, copper). Values between 0.2 and 0.8 are almost always wrong; they produce energy-non-conservative renders that look "plasticky."

Exception: dark mirror lenses (sunglasses) use ~0.8 to combine strong reflection with slight tint — that's a stylistic choice, not strict PBR.

Decision tree