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• The transportTrait tells the Bxdf the subset of light transport to consider: direct illumination, indirect illumination, or both. 
• lobesWanted specifies what lobes are requested, for example specular reflection, diffuse transmission, etc. 
• rng should be called to generate well-stratified samples; such samples typically reduce noise and improve convergence compared to using uniform random samples. 

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• RixBxdf::GetPresence() to evaluate the geometry presence.
• RixBxdf::GetOpacity() to evaluate the opacity color.

Installation

RenderMan will search for bxdf plugins on demand, under the rixplugin searchpath. The following rib stream will search for a plugin file named MyDiffuse.so

Bxdf "MyDiffuse" "diffuse1" "color tint" [0.5 0.5 0.5]

Creating a Bxdf args File

If you would like RenderMan for Maya or Katana to recognize your Bxdf and provide a user interface for changing input parameters and connecting output parameters to other nodes, then you will need to create an args file for your bxdf. The args file defines the input and output parameters in XML so that tools like RMS or Katana can easily read them, discover their type, default values, and other information used while creating the user interface for the pattern node. Please consult the Args File Reference for more information.

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Additional Considerations

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