Hi, thank you for the response. Cutting down the number of static meshes in total isn’t really an option as those are defined by the needs of the level, nanite is also handling the large count of rocks in the environment very well. The rock in question has about 4,000 tri’s. My instinct is having two seperate copies of the rock present in the level, a mossy one and a snowy one, for a unique total of 8,000 tri’s is probably preferable to having only one version of the rock present but then dealing with 5,000 instances having overriden materials. I’m sure on a small scale it would be irrelevant but once there’s thousands of overriden default material slots I’m guessing that might start causing a performance hit.