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Below is a simple exploration of each choice and how they are designed to be used. Note that we use the term "lobe" to describe each illumination lobe of the material. Diffuse is a lobe, as are Primary Specular, Clearcoat, and so on.

For a more technical exploration of the materials and usage at Pixar, take a look at our research paper. (PDF)

PxrSurface

PxrSurface is the complete material package. It provides all of the available options and parameters for making just about anything. The user has the ability to combine any lobe and also layer them (using PxrLayerMixer) for simple to complex surfaces. This material choice is useful for many surfaces where artistic freedoms are more important than strict realism. The production materials in RenderMan are from this same family and despite having different options, their parameters are all related. As such, the PxrSurface parameters are your source for how to tweak and manipulate options for your desired look.

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