Ditto this post. In my Bullet work, the physics representation is based on, but separate from, the OSG visual representation. The two "graphs" are only tied together at Transform nodes that allow Bullet to drive the transformations of the visual representations of rigid bodies.
Paul Martz Skew Matrix Software LLC http://www.skew-matrix.com +1 303 859 9466 -----Original Message----- From: osg-users-boun...@lists.openscenegraph.org [mailto:osg-users-boun...@lists.openscenegraph.org] On Behalf Of Paul Speed Sent: Wednesday, January 14, 2009 3:08 PM To: OpenSceneGraph Users Subject: Re: [osg-users] [osgPhysics] Project osgPhysics started! My experience is admittedly limited here, but I think some of us are coming from the position that your physics "graph" is an entirely different thing than the render "graph". The two are often completely orthogonal. In one case you may have physics body represented by something simple like a ball... where as for various implementation reasons your scene graph may need to be a whole pile of objects. Conversely, sometimes a whole mess of physics parts/bodies/bones/whatever may decompose into a single mesh and a custom shader to move the points around. While there may be parts similar between a physics "node" and a scene graph "node", I'm not sure they are similar enough to justify being related in a class hierarchy. ...and maybe you are already taking all of that into consideration and I've misunderstood the conversation so far. It just sounds like you are trying to have the physics engine directly "act" on scene graph nodes versus transferring values transform information from the physics nodes to the scene graph nodes. I think you will pay dearly for the "convenience". :) -Paul Sukender wrote: > Hi David, > > Well, what we intend to do is simply provide a "plug" so that you can do what you want. Morover, the osgPhysics' aim is to drive nodes in the graph by the way of physics. We don't plan to make physic objects to be "cullable", or things like that. Changeing the renderer (like raytracing) would not affect things handled by osgPhysics. > I hope this is a bit clearer! :) > > About Adrian, I also discussed a few points with him, and I may > contribute to PAL too. And yes, he's in Australia... Wang Rui > (osgPhysics, osgNV) is in China, and I'm in France... well it may be > difficult to be all online for a chat, but we still can work :) > > Sukender > PVLE - Lightweight cross-platform game engine - > http://pvle.sourceforge.net/ > > >> I guess I understand why people do it, but I would rather that OSG kept the limited scope of being a scene graph, that is with the features just of doing 3d rendering. I think a more limited scope makes it more useful as a drop in component of a game engine. >> >> physics and audio, while they are necessary in a game or simulation engine, they are not rendered, and I don't think they belong in a scene graph. In delta3d, we have, and are more and more trying to separate things such as drawing, physics, and audio from simulated objects (actors) so that actors can be composed of these features via componentization and messaging. We would eventually even like delta3d to have the ability to use different renderers. >> >> As technologies like raytracing become more prevalent, the scene graph may have change a fair bit, but that shouldn't affect the audio and physics systems. >> >> Originally we had wanted to work with Robert more closely to make delta3d have game engine features, and osg have the rendering features, but things didn't evolve that way. >> >> Either way, this is not a discussion for the osgPhysics list. I'm making dtPhysics, which appears to have nearly exactly the same goals as you have except that we intend to integrate with delta3d its component system. >> >> I email back and forth with Adrian Boeing a fair bit, and I have commit access to PAL, as I said before, so we would discuss the features and direction of PAL, as we see it. Perhaps PAL needs a mailing list, or maybe we need to do something more like a telecon to discuss things. I don't know where in the world you are. I'm on the east coast of the US. Adrian is, I think, in Australia. So, I'm not sure how practical that is. > > _______________________________________________ > osg-users mailing list > osg-users@lists.openscenegraph.org > http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph. > org _______________________________________________ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org _______________________________________________ osg-users mailing list osg-users@lists.openscenegraph.org http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
