Path: utzoo!utgpu!watmath!clyde!att!osu-cis!tut.cis.ohio-state.edu!mailrus!cornell!uw-beaver!rice!titan!foo From: foo@titan.rice.edu (Mark Hall) Newsgroups: comp.graphics Subject: Re: Polygon Representation of a Sphere's Surface Summary: you may have do discover a new "Platonic" solid Message-ID: <2908@kalliope.rice.edu> Date: 22 Mar 89 23:26:26 GMT References: <270@ai.etl.army.mil> Sender: usenet@rice.edu Reply-To: foo@titan.rice.edu (Mark Hall) Organization: Rice University, Houston Lines: 31 In article <270@ai.etl.army.mil> richr@ai.etl.army.mil. (Richard Rosenthal) writes: >I want to have in 3-D space (x, y, z) a polygon near-representation >of the surface of a sphere where each polygon is identical >and regular (if that's the word). > >Is an icosahedron the right place to start? > >I would like to be able to generate the representation with >increasing numbers of polygons, say first 20, and then >say 80. >Richard Rosenthal Internet: richr@ai.etl.army.mil I think you are going to have a problem. As I remember the argument from a class a few years ago: One way to tile a sphere with regular (all sides/angles equal) polyhedra is to take a regular solid centered at the sphere's center. Project the edges of the solid onto the sphere. Works just fine. The kicker is that there are only 5 known regular solids. (Not counting the teapotahedron - see CACM Feb. 1988 cover) If you do discover a tiling with millions of regular shapes, you should be able to run the above process in reverse to create a new regular polyhedral solid. Good luck. - mark