Hi David, Have a look at the osgParticle::PrecipitationEffect implementation as this reuses a single osg::Geometry instance many times. The Geometry uses vertex arrays rather than display lists.
Robert. On Fri, Nov 28, 2008 at 7:31 PM, David Spilling <[EMAIL PROTECTED]> wrote: > Paul, > > If this was raw OpenGL, I'd be tempted to set up my heightfield as a display > list, and then change the modelview matrix for each call to the display > list. I'm not quite sure how to force similar behaviour in OSG other than to > set up the scenegraph with multiple PATs. > >> I'm working on a similar problem: rendering a large vector field as >> several arrows, all with different positions and orientations. If >> I multiparent the Geometry to several PAT nodes, the cull time cost is quite >> high. > > I have the notion that cull times can be improved by not letting the cull > traverse go across the PATs. The parent of the PATs probably knows something > that could limit the set of PATs that actually needs to be traversed in the > draw. In my application that's certainly true - the top "Group" gets the > view/projection matrices, and since each tile is the same size, can decide > which of it's children really need drawing without having to check the > bounding spheres of its many PAT children. > > Unfortunately, my heightfield does sometimes change and so I haven't really > pursued the tradeoff between the cost of display list compiles and other > techniques. > >> I'm looking at adding support for ARB_draw_instanced to reduce both the >> cull and draw time > > If you get anything working, I'd be delighted to test it in my context, time > permitting (by then I will have probably got the codepaths for the various > other techniques going). > > David > > _______________________________________________ > osg-users mailing list > [email protected] > http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org > > _______________________________________________ osg-users mailing list [email protected] http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
