Having a duhh moment here but how do I do this?
I have a car and want to instance it as a proxy but have the instances look different by having different materials applied to the car paint element.
I can do it with the random colour colour map plugged into a gradient map plugged into diffuse but that only works for different colours.
I need to use different materials as some of the car paint materials are a mix of 2 materials and not just different colours and, very annoyingly, I can't just plug my car materials into the map slots of the gradient map...