butch@fergvax.unl.edu (FERGVAX Daily Operator) (06/26/91)
I'm working on a polygon-based 3D graphing application and I need a good sorting algorithm for the faces. I've worked with just sorting on a Z value (which I know doesn't work, but was enough to show my off the program at the time) and I've looked in Foley-Van Damm at the Newell-Newell-Sanchez algorithm. The latter I like and it's precisely what I'm looking for. However, I'm stuck: So, I've got some questions: (1) How can you tell if one polygon is completely on a one side of another polygon, and (2) There are cases where adding a test for (1) does not completely insure a correctly sorted face list, so could anyone recommend some extra criteria for correctly sorting non-intersecting polygons? Please e-mail me at butch@fergvax.unl.edu if you can help me. Thanks in advance, Butch