@sarahlenker basically I’m creating a couple of variations for each material slot of each room. So each atlas will be used multiple times by a room type that in turn will be present multiple times as hism. For example, a room type can be customized via atlas, with a type of wall, floor, ceiling. So each room has its own atlas, and in the reference atlas there are only textures for the slots of that room. My idea was this. So that I could have a random combination for each slot. I wanted to create a unique material that through a function and a parameter defined which atlas to use for that room. I hope you understand what I mean.