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In the simple example above, outColor is assigned the buffer that was allocated corresponding to the private enumeration value k_resultRGB, which matches the position of that output in the parameter table.  We (So long as the output parameters are at the beginning of the parameter table, reuse of this enumeration is valid for this purpose.) We assume the style variable was a uniform RtInt input value, so there is only one value for all the points in the shading context. Meanwhile, the inputColor and inputFloat  variable were varying instead of uniform, so they are pointers to an array of RtColorRGB values and array of RtFloat values respectively, one for each shaded point in the shading context.

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Display "patternTest" "framebuffer" "rgba"
Quantize "rgba" 255 0 255 0
Format 128 128 1
Projection "perspective" "fov" [45]
Hider "raytrace" "string integrationmode" ["path"]
Integrator "PxrPathTracer" "integrator"
WorldBegin
    AttributeBegin
        Attribute "identifier" "name" ["sphere1"]
        Translate 0 0 2.75
        Pattern "PxrCustomPattern" "customPattern"
        Bxdf "PxrDiffuse" "smooth"
            "reference color diffuseColor" "customPattern:outColor"
        Sphere 1.0 -1.0 1.0 360.0
    AttributeEnd
WorldEnd

Creating a Pattern args File

If you would like RenderMan for Maya or Katana to recognize your pattern plugin 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 pattern. 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.

Texture Baking

RenderMan can optionally bake pattern outputs to 2D or 3D textures by evaluating those patterns over an output manifold. Pattern plug-ins that wish to bake outputs should provide custom implementations of the RixPattern::Bake2dOutput or RixPattern::Bake3dOutput methods that return true. When in bake mode, RenderMan queries these methods to describe the output manifold and to initialize display drivers. For 2d atlas/UDIM outputs that set RixPattern::Bake2dSpec::atlas to true, RenderMan will query RixPattern::Bake2dOutput once for each UV tile.

It is possible to write a generalized baking node that reference bakes the output of arbitrary upstream pattern graphs. For referenceexample, see PxrBakeTexture and PxrBakePointCloud pattern plug-ins:

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