How do I set a shader param of an instance of a mesh instance

AI_Messiah

This is in my material no 3 and they are named High Dig and Low Dig in this case

Megalomaniak

If it's not a unique instance I'm not sure you can set it individually. So might have to make it a unique instance first. Maybe show us your scene and scene tree too?

AI_Messiah

I have found the method, but I cant get the right material. I put this in my next question