Yazel, David J. wrote: >The fastest approach would be to store your triangles in vworld form in an >oct tree and cast a ray against it. This would be in addition to the >geometry used to display. If speed is not absolutely essential then divide >your geometry up into multiple non-intersecting bounds and let Java3d pick >the shape using a ray -> bounds check. Once you have the nearest >intersecting shape you can either scan the triangles yourself, or cast the >ray just against that shape using geometry intersection. > May I be so bold as to ask if there exist any examples on how to construct and use the oct tree approach, since speed is indeed essential.
Does there exist support in the Java3D or vecmath APIs for using oct trees? Best Regards, Roger Berggren >Dave Yazel > >-----Original Message----- >From: Roger Berggren [mailto:[EMAIL PROTECTED]] >Sent: Wednesday, June 05, 2002 3:51 AM >To: [EMAIL PROTECTED] >Subject: [JAVA3D] Fastest way to find intersection point > > >Hi, > >I'm trying to find the closest intersection point between the mouse >position and a huge (700, 000 vertices) Shape3D. > >What is the best approach to try to find the closest intersection >point as fast as possible. > >I have tried the com.sun.j3d.utils.picking classes, but for this size >they seem a bit slow, but they find the local coordinates correctly. > >I also tested the IntersectionUtils from org.j3d.geom. They seemed >faster, but instead I have problems getting them to work correctly. > >So I have one that's slow but correct and one that's fast but >not working :-) > >How do one best organize the scenegraph with such a large >Shape3D for best picking performance? > >Do you have 70 Shape3Ds with 10000 vertices or >1 Shape3D with 70 geometries or a single GeometryArray? > >Any ideas, thoughts or examples are greatly appricated. > >Best Regards, > >Roger Berggren > > > =========================================================================== 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".
