Re: Polygons on spheres
- To: mathgroup at smc.vnet.net
- Subject: [mg54759] Re: Polygons on spheres
- From: "Jens-Peer Kuska" <kuska at informatik.uni-leipzig.de>
- Date: Tue, 1 Mar 2005 01:58:14 -0500 (EST)
- Organization: Uni Leipzig
- References: <cvukq6$bdq$1@smc.vnet.net>
- Sender: owner-wri-mathgroup at wolfram.com
Hi, a) Mathematica uses PostScript and PostScript can't display transparence b) MathGL3d can do this, if you send me the code I will do it for you c) Michaels books are excelent and you should buy one for you and several copys for your friends Regards Jens "Steve Gray" <stevebg at adelphia.net> schrieb im Newsbeitrag news:cvukq6$bdq$1 at smc.vnet.net... > I have a need to draw and display "polygons" on spheres. The edges of the > polygons will all > be arcs of great circles. Examples are triangles, etc., and n-sided > polygons which usually > self-intersect. The great circle arcs must stop at the vertices, which > presumably can be done by > correctly setting the range in the parametric plots of the edges. > Obviously several edges must be > displayed at the same time, up to a dozen or two. > I want to see what these figures look like when the vertices are moved > around on the sphere, > probably one at a time, constrained by certain rules. I would like to see > the sphere as a colored > surface with the lines standing out. I can specify the vertices by > theta-phi or whatever. My main > concern is getting a good display, not the actual math. I will need to > vary the point of view to > look at different parts of the sphere and maybe make an animation. > The part I'm uncertain about is getting a sphere and the lines to show at > the same time, and > how to choose whether the lines on the back side of the sphere are visible > or not, so options should > be transparent vs. translucent vs. opaque sphere. > Any suggestions will be welcome. Does anyone know if Trott's book on > Mathematica display coding > covers this? If it will help, I'm willilng to buy it. > > Steve Gray >