## AW: [Algorithms] Computing brush center from plane equs

 AW: [Algorithms] Computing brush center from plane equs From: - 2004-04-26 16:03:14 ```If the volume isn't too complex why not try solving it iteratively, ie. = Add one plane at a time to the existing solution. -----Urspr=FCngliche Nachricht----- Von: gdalgorithms-list-admin@... = [mailto:gdalgorithms-list-admin@...] Im Auftrag von = Pierre Terdiman Gesendet: Montag, 26. April 2004 18:00 An: gdalgorithms-list@... Betreff: [Algorithms] Computing brush center from plane equs Hi, I have a set of planes in world-space. They define a convex volume, = think something like a Quake brush. The goal is to compute the vertices = of that volume, from the set of planes. The way I did that before was to convert the planes to dual space, = compute a convex hull in that space, convert it back, and this gives the = desired vertices. Until now my planes where defined in local space, and the origin was = always guaranteed to be inside the volume, so there was no problem with = the dual transform. But now I have some planes in world-space, at arbitrary position. I'd = like to translate them so that the origin lies at the center of the = volume. So I need to compute this center, from the planes' equations - = that is, without first computing the actual vertices, of course (since = that's the goal...). I came up with an iterative algo that somehow seems to work, but I'm not = even sure to understand why. So I'd like something better. Any ideas ? I'd like to avoid doing the actual clipping.... - Pierre ------------------------------------------------------- This SF.net email is sponsored by: The Robotic Monkeys at ThinkGeek For = a limited time only, get FREE Ground shipping on all orders of \$35 or = more. Hurry up and shop folks, this offer expires April 30th! = http://www.thinkgeek.com/freeshipping/?cpg=3D12297 _______________________________________________ GDAlgorithms-list mailing list GDAlgorithms-list@... https://lists.sourceforge.net/lists/listinfo/gdalgorithms-list Archives: http://sourceforge.net/mailarchive/forum.php?forum_id=3D6188 ```

 AW: [Algorithms] Computing brush center from plane equs From: - 2004-04-26 16:03:14 ```If the volume isn't too complex why not try solving it iteratively, ie. = Add one plane at a time to the existing solution. -----Urspr=FCngliche Nachricht----- Von: gdalgorithms-list-admin@... = [mailto:gdalgorithms-list-admin@...] Im Auftrag von = Pierre Terdiman Gesendet: Montag, 26. April 2004 18:00 An: gdalgorithms-list@... Betreff: [Algorithms] Computing brush center from plane equs Hi, I have a set of planes in world-space. They define a convex volume, = think something like a Quake brush. The goal is to compute the vertices = of that volume, from the set of planes. The way I did that before was to convert the planes to dual space, = compute a convex hull in that space, convert it back, and this gives the = desired vertices. Until now my planes where defined in local space, and the origin was = always guaranteed to be inside the volume, so there was no problem with = the dual transform. But now I have some planes in world-space, at arbitrary position. I'd = like to translate them so that the origin lies at the center of the = volume. So I need to compute this center, from the planes' equations - = that is, without first computing the actual vertices, of course (since = that's the goal...). I came up with an iterative algo that somehow seems to work, but I'm not = even sure to understand why. So I'd like something better. Any ideas ? I'd like to avoid doing the actual clipping.... - Pierre ------------------------------------------------------- This SF.net email is sponsored by: The Robotic Monkeys at ThinkGeek For = a limited time only, get FREE Ground shipping on all orders of \$35 or = more. Hurry up and shop folks, this offer expires April 30th! = http://www.thinkgeek.com/freeshipping/?cpg=3D12297 _______________________________________________ GDAlgorithms-list mailing list GDAlgorithms-list@... https://lists.sourceforge.net/lists/listinfo/gdalgorithms-list Archives: http://sourceforge.net/mailarchive/forum.php?forum_id=3D6188 ```