I tried, but i can't get it to work ... What object do you use ? I've tried with a plane, a sphere and a cube, and got really weird results . Maybe it's because my computer works with european maths, you know 2,5 means 2.5, these kind of things ... But i doubt it, Carrara usually understands both ways . Too bad, i wanted to use it as a bump on a transparent and refractive plane to make a spherical distortion, like a magnifying glass :( Would you mind to send me the file so i can have a look at it ? litst@chez.com