Many thanks to Mark for the information. I am trying to write some simple triangulation code myself, which is optimized by some curvature. Hope it works for my simple restrained input polygons.
regards, ---white On Fri, 14 Feb 2003 15:55:56 -0800, Mark Hood <[EMAIL PROTECTED]> wrote: >> Date: Fri, 14 Feb 2003 14:28:21 -0700 >> From: White Morph <[EMAIL PROTECTED]> >> >> If Java3D does use FIST code for triangulation, then I guess it doesn't do >> the sorted or random optimization that is mentioned in the paper, because >> each time I run a program, it always get the same triangulation, on the other >> hand, if I change the starting vertex, it normally gets a different >> triangulation. > >GeometryInfo uses a Triangulator constructor that sets the sorted and random >ear modes to false. I don't know the reason behind this choice; there may have >been some problem with those modes that it made it not worth using for Java 3D. >Paul might have some insight into this. > >If you think this might be a bug, the best thing to do is submit a bug report >so we'll have some justification for looking into this complex bit of code. Is >there a problem in your application that would definitely be solved by using >sorted or random ear optimization? > >Triangulator is probably not using the latest version of FIST. It appears to >be using code derived from FIST 1.6. The last update to the Java 3D derived >code was a bug fix on February 25 2002. > >> By the way, I wonder why Java3D doesn't use the Constrained Delaunay >> Triangulation, which even the author of FIST admits has better triangulation >> quality. > >Good question. We've been using the FIST code since early 1998. It was >probably a matter of what code was already available from the relationships >that we had at the time vs. the resources that we had to develop a robust >triangulator ourselves. Triangulators are notoriously difficult to get right >for "industrial-strength" applications. Again, Paul might have some insight >into this. > >The Triangulator class is a utility, not part of the Java 3D core, so if you >need to use an alternative triangulation algorithm there's no technical reason >why you can't substitute whatever you need. > >-- Mark Hood > > ========================================================================== >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".
