HELP!!! How to do a projection of a shape on a surface?

Project title: Projecting any single shape onto a given plane surface.

Now solution: Using HiddenLine algorithms (HLR class).

Now step: Got the edges of projection.

Problem: I can not get the profile(outline) of this projection.

If you want know more about this, I can email some coding and figure to you.

Please help me! Thanks a lot!!!

"When you make eyes in place of an eye, a hand in place of a hand, a foot in place of a foot, an image in place of an image, then you will enter." - logion

Shen Zhong
robertshen@21cn.com or robert_shen@hotmail.com