Thip....Rhino does that automatically with the "contour" tool. you just define the parameters, and the program does the rest. try out the demo...i hear the new demo has 50 saves, as opposed to 25 on the old one. it's all fully functional. and, you know...i would not steer you wrong...you got me started with this modelling addiction, back in the amapi forum...(still have never figured out how to do that dragon head tute that came with the free version....arrrghhh).