Thank you, I think this is just about it.
Margus
Chris Huff wrote:
> > This might be close to what you want, they aren't exactly concentric,> more like stacked:> box {< -5, -5, 0>, < 5, 5, 5 >> texture {> pigment {> function {sqrt(x^2 + z^2)-y}> color_map {> [0 color Black]> [1 color White]> }> }> }> }
