Hi Pasi, I checked the post and tried the example. The problem of not correctly triangulated is just because of you listed the boundary vertices in clockwise order, if you change that order to counterclockwise, you'll get the correct result.
----white <[EMAIL PROTECTED]> wrote: >At least we have a consistent problem in triangulation. See my colleaque >Tero Karhunen's posts: > >http://swjscmail1.java.sun.com/cgi-bin/wa?A2=ind0301&L=java3d-interest&P=R18 >830 >http://swjscmail1.java.sun.com/cgi-bin/wa?A2=ind0301&L=java3d-interest&P=R33 >477 > >These both mails contain one example of a very simple geometry that doesn't >get triangulated right. Nobody from the Java3D group has commented these so >far. It would be nice to hear your analysis of these. > >Pasi > >-----Original Message----- >From: Discussion list for Java 3D API >[mailto:[EMAIL PROTECTED]]On Behalf Of Mark Hood >Sent: 15. helmikuuta 2003 1:56 >To: [EMAIL PROTECTED] >Subject: Re: [JAVA3D] Some questions about triangulation in Java3D > > >> 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".
