Thanks for the comments. I have a few more fractals coming in the next few days. With regard to the speed issue, the slow part is making the model. Once you have the model it only takes a minute or so to render even the most complex model I can make. The biggest problem with the speed concerns dividing the calculation into parts. I thought my "layer cake" approach of making the model one iteration band at a time divided the problem well enough. Even with that, I still end up with individual polygons with 10's of thousands of points. Many of the calculations in making the model take N x N operations (or even N cubed) where N is the number of points in the polygon. The solution may be to divide the large polygons into smaller ones but that adds even more complexity since the large polygons often have many long thin arms and holes. When large polygons are cut into smaller polygons, holes could overlap more than one polygon. I will probably revisit the algorithms and code in another few months. I had thought about possibly adding network rendering but it wouldn't help me that much. Over the years I usually have one relatively new computer and one or more really old ones that are much much slower. Unless I can divide the problem into a lot more pieces it probably isn't worth it. -- Mike Frazier www.fracton.org