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Color is typically where textures or patterns are connected to create color for opaque objects. This is where a wood color texture would go, for example.

Roughness

Diffuse roughness is how you would simulate a powdery surface like dried clay or dust.  When roughness is 0.0,  LamaDiffuse uses the Lambertian model to calculate the diffuse response.  When roughness is > 0.0, the Oren Nayar model is used instead.

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