## RE: [Algorithms] Animation and change of root

 RE: [Algorithms] Animation and change of root From: Gribb, Gil - 2004-11-09 18:49:28 ```Well if you have a heirarchy, something has to be at the root. And the = concept of a heirarchy is not at all artifical. If I bend my elbow, my = fingers move. But if I move my fingers, my elbow doesn't move. Quite a = natural relation. -Gil -----Original Message----- From: gdalgorithms-list-admin@... [mailto:gdalgorithms-list-admin@...]On Behalf Of Jonathan Blow Sent: Tuesday, November 09, 2004 12:39 PM To: gdalgorithms-list@... Subject: Re: [Algorithms] Animation and change of root "The root" of a skeleton is a pretty artificial concept that has mostly=20 outlived its usefulness. Most people still do things that way, but it's = not a great idea. Dynamic re-rooting of a skeleton is pretty easy; the annoying part is=20 when you have all this animation data that's stored bone-relative and=20 you're like, hey, what do I do with all this stuff? The most=20 straightforward thing is to evaluate that animation on a spare skeleton=20 that has a fixed root, to get the object space transforms, then=20 re-compute bone space transforms for the new hierarchy based on that.=20 (If you like bone space, which a lot of people on this list seem to.) =20 Anyway, that's not "fast" if you are thinking=20 I-am-peephole-optimizing-my-algorithm fast, but it's O(n) with the=20 number of bones, so hey, whatever. But if you have time to actively experiment on this stuff, I would=20 explore doing things without a root. Chris Haarmeijer wrote: >Hi, > >For an animation system, I have to change the root of the system = frequently >from the left foot to the right foot. Are there any publications = available >on the subject of fast changing of the root of an animation hierarchy ? > >Kind regards, > >Chris Haarmeijer >--- >Keep IT Simple Software >Van Alphenstraat 12 >7514 DD Enschede > >W: http://www.keepitsimple.nl >E: mailto:info@... >T: +31 53 4356687 > > > >------------------------------------------------------- >This SF.Net email is sponsored by: >Sybase ASE Linux Express Edition - download now for FREE >LinuxWorld Reader's Choice Award Winner for best database on Linux. >http://ads.osdn.com/?ad_id=3D5588&alloc_id=3D12065&op=3Dclick >_______________________________________________ >GDAlgorithms-list mailing list >GDAlgorithms-list@... >https://lists.sourceforge.net/lists/listinfo/gdalgorithms-list >Archives: >http://sourceforge.net/mailarchive/forum.php?forum_id=3D6188 > > =20 > ------------------------------------------------------- This SF.Net email is sponsored by: Sybase ASE Linux Express Edition - download now for FREE LinuxWorld Reader's Choice Award Winner for best database on Linux. http://ads.osdn.com/?ad_id=3D5588&alloc_id=3D12065&op=3Dclick _______________________________________________ GDAlgorithms-list mailing list GDAlgorithms-list@... https://lists.sourceforge.net/lists/listinfo/gdalgorithms-list Archives: http://sourceforge.net/mailarchive/forum.php?forum_id=3D6188 ```