PxrVary

The PxrVary pattern allows for random variation.  Let's try varying the color of the teacups based on the Particle ID.

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This causes a primvar called particleId to be available on the instances.

Next, wire a PxrVary pattern into the color of the material used for each of the cup and the saucer. 

Set up the PxrVary to use the particleId as its seed for randomization.  

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