Is it possible to somehow use UV islands as a factor for things in Cycles? For example, I want to use a different procedural texture on each UV island, or factor between different shaders for each UV island?
I know this is not a readily available output from any node, but is there a way to construct something like it from available nodes, even if it's not precise?
I would like to achieve an effect similar to manually rotating UVs in the UV/Image editor, but without actually changing the map. For example, consider if I had a character in a T pose whose arms and legs were unwrapped as separate islands. If I use a horizontal wave texture, it would be parallel to the arms, but perpendicular to the legs. If i wanted it parallel to the legs, I'd rotate the leg's UV island by 90 degrees. I would like to be able to do this with nodes inside a material without having to touch the UV map or create multiple UV maps.