I was just using the Icosahedron as an example. Could be that the polyhedron has 120 vertices or more. I don't want to work out by hand which vertex is connect to which other vertices. I'd like a program to figure that all out. Could be a mixed (concave/convex) polyhedron. The terrain correspondence is pretty good, but I know the "terrain" bends around and closes on itself to form a polyhedron of some kind.
Anyone have an example of such a method? Cheers, Bob Gray -----Original Message----- From: Discussion list for Java 3D API [mailto:[EMAIL PROTECTED] Behalf Of White Morph Sent: Tuesday, March 11, 2003 1:22 PM To: [EMAIL PROTECTED] Subject: Re: [JAVA3D] AW: [JAVA3D] How to form the Geometry? If you just know the coordinates of a bunch of vertices, no other topological information, then the problem is like the terrain modeling, in which only a grid of elevation data known. For this kind of problem, I think there are lot of algorithms and programs for it. Delaunay triangulation is a popular algorithm for that. For your example, if you know it's a Icosahedron, then you have the topological information, I don't know why you say you don't have other information. ---white >I don't know of any 3D program which takes an array of arbitrary coordinates >and transform them into a 3d shape without giving more informations on how >to create the faces. > >However, if you know that you have some sort of aprox. regular shape, you >can do some maths to determine how the faces should look like. First, >determine the geometrical center of your polyhedron. Then you can for each >point determine the angles phi & theta relative to the center of the shape. >That will help you to arrage the points in a (phi, theta) grid on which you >can perform a triangulation. > >If you know some more info about the points, like the order of them, you >should try to use that. > >Cheers, > >Florin > >-----Urspr�ngliche Nachricht----- >Von: RWGRAY [mailto:[EMAIL PROTECTED] >Gesendet: Dienstag, 11. M�rz 2003 16:57 >An: [EMAIL PROTECTED] >Betreff: [JAVA3D] How to form the Geometry? > > >Is there a class/method/utility which will take an array of polyhedron >vertex coordinates and return a TriangularArray for the polyhedron? > >For example, I have the coordinates for an Icosahedron, but no other >information. Is there a utility I can call with these coordinates to get >back a TriangleArray for the Icosahedron? > >I looked at GeometryInfo, but it looks like you need to first know which >combination of vertex coordinates forms the faces of the polyhedron. > >Cheers, >Bob Gray > >=========================================================================== >To unsubscribe, send email to [EMAIL PROTECTED] and include in the body >of the message "signoff JAVA3D-INTEREST". For general help, send email to >[EMAIL PROTECTED] and include in the body of the message "help". > > =========================================================================To unsubscribe, send email to [EMAIL PROTECTED] and include in the body >of the message "signoff JAVA3D-INTEREST". For general help, send email to >[EMAIL PROTECTED] and include in the body of the message "help". To unsubscribe, send email to [EMAIL PROTECTED] and include in the body of the message "signoff JAVA3D-INTEREST". For general help, send email to [EMAIL PROTECTED] and include in the body of the message "help". =========================================================================== To unsubscribe, send email to [EMAIL PROTECTED] and include in the body of the message "signoff JAVA3D-INTEREST". For general help, send email to [EMAIL PROTECTED] and include in the body of the message "help".
