bdiscoe@tybalt.caltech.edu (Ben W. Discoe) (10/25/89)
I am in the planning stages of a program that dynamically displays the world map as composed of triangles, the surface of the world projected on an icosahedron. Some people may know this as "Fuller Projection" or as the Dymaxion Map. The trouble I am having is determining what coordinate system to use for points on the world's surface. Initially I thought to use straightforward lattitude-longitutde lines but then realized this would require as fair amount of calculation to project each point on the world's surface on to one of the 20 faces of the icosahedron. The next idea I tried was using an internal numeric tag for each of the faces (0-19) and set up a adjacency table to determine the way in which the faces fit together to form the surface. However, two more coordinates (x y) are required to describe the location of each point, and finding the shortest path between two points on any two faces becomes inhibitively complex. Besides, it really shouldn't take three coordinates to label a point on a sphere's surface! Unless this makes things easier. Has anybody worked with this kind of projection/coordinate scheme before? I would be most appreciative of any tips on schemes which minimize algorithm complexity. Thanks a bundle in advance. -Ben "struggling starving student stereotype" "Amiga 1000, STILL the best"