PxrMatteID

Three MatteID AOVs setup to reflect material assignments

This node outputs AOVs for compositing. It should be plugged into the inputAOV parameter of a LM Shader and will output MatteID AOVs.

It outputs at most eight RGB mattes (24 mattes) named MatteID0, MatteID1 ... MatteID7.

MatteID AOVs are used as per-objects/per-object groups/per-material compositing mattes. They will be properly motion-blurred or defocused to allow you to isolate objects in your compositing software.

To associate an object or a shader to a MatteIDx, you need to add a special attribute to that object or shader:

Attribute "user" "color MatteID0" [1 0 0]

In this example, the MatteID0 AOV will be red for your object, but you can use the green and blue channel for two other sets of objects.

In RMS, these attributes can be found via the Manage Attributes menu, and there is a MatteID tab in the Outputs section of the RenderMan globals. For an example of PxrMatteID in action, check out the video!