chuck@sunpix.UUCP ( Sun Visualization Products) (08/30/89)
A while ago someone (from Duke, I believe) posted a request for help in interpolating sampled data values across a three-dimensional surface represented as a polygonal mesh. I just came across a reference that will help him, but I have since lost the original message, hence the post. Mayhap others may find it useful. In the latest issue of IEEE PAMI (Vol 11, No. 9, Sept. 1989) on pp. 1001-1005 there is an algorithm for computing geodesic (i.e., minimal) distances on a three-dimensional polyhedral surface. Once you have a routine to do this, computing a color (or voltage, or whatever) at any point on the surface is straightforward. The algorithm's "computational complexity per se is not favorable". It in fact appears to be exponential, but with the relatively small number of polygons involved in both the author's and the original requestors applications (order of magnitude 1000) it is not prohibitive. The title and authors: Computing Minimal Distances on Polyhedral Surfaces by Estarose Wolfson and Eric Schwartz Hope this is helpful. P.S. There is an amusing misprint in the summary which points out the need for care in notational script: "This run took about 2 hours and used 12 ubytes of memory". Now there's a space-efficient algorithm! Chuck Mosher Visualization Products, Sun Microsystems cmosher@sun.com