Thanx and welcome :) I hoped someone with a more decent english knowledge will do some tutorial from the pure nodes i made ;) And yes, Ajax was right about the restrictions of the geometry , but as always there is no general solution for a shader problem like this; since only a geometry built up from fractals would be perfect(which is mostly true for the real world(...)). About the last adviced restriction, im not quite sure if the difference will be just a small amount. I have to look at it more since i didnt think about a shorcut like that, but as far as i feel know it wont be a better result, but will be quicker by far. Since its a bit more comlex than just say something vaguely, ill check and let you know about the result. (And yes that requires more from those nasty vector calculus.)