Jonathan Mack

I found using the geompropvalue to get 'I' also works, and works correctly in reflections.

Edit: it doesn't seem to work in XPU though

The mechanism by which they are translated to vex is different. MaterialX is JIT converted from the graph while rendering, whereas vex vops generate code directly when generating the USD. MaterialX vops could theoretically generate vex code too and be mixed with other vex vops, but this would generate a vex shader and someone defeat the purpose of using an open interchange format. It would also be incompatible with XPU.

rangi
Yeah, thanks for pointing that out. Looks like it should do the trick. Just doesn't work for me. I'm putting it into a prune lop. Testing with a simple bbox it's pruning the instances fine.

It's not a bug, collections cannot target instances. The bound collection can only intersect with the bounding box containing all of the instances.