In this thread someone says "use the instance id in your shaders to index into the arrays." Is there really a way to access the instance id as a integer value in the shader? On this page about GPU Instancing it refers to UNITY_INSTANCE_ID but if I try using that in my shader I get an error. Same for SV_InstanceID which it mentions. The UNITY_SETUP_INSTANCE_ID() function is working fine for me, but I don't know how to access the actual ID. I'm on 2017.2 so I'm not out of date. I guess my thought is, if I have some attributes I want to vary, I could have it changed based on the ID without making additional properties for the MaterialPropertyBlock.