Hi Sean, In general when moving from display listed data to VBO's it's best to avoid using tri-strips with separate osg::DrawElements and instead using a single osg::DrawElements containing just GL_TRIANGLES. This will be more duplicated indices but far less overhead in set up and dispatch.
With modern graphics hardware and API the biggest overhead is typically the dispatch rather than vertex load on the GPU. Even mid range GPU's can comfortable handle a million+ vertices per frame at 60hz, but... you have to pass the data to them efficiently, and the bottlenecks we were once familiar with have changed. Robert. On Fri, Dec 17, 2010 at 6:57 PM, Sean Spicer <[email protected]> wrote: > Robert, > > Some more data... > > Looks like we're drawing approx 100K tri-strips every frame. The > glDrawElements call is the culprit...though I'm still baffled by why > it is so much slower with VBOs than in immediate mode. Perhaps the > drawing isn't sorted by VBO so that all of the triangles drawn from > each VBO are draw in single bind call ? > > sean > _________________________________________________________ > Sean Spicer > Aqumin (www.aqumin.com) > Office....+1.713.781.2121 > Mobile...+1.713.447.2706 > Fax.......+1.713.781.2123 > > > > On Fri, Dec 17, 2010 at 11:37 AM, Sean Spicer <[email protected]> wrote: >> Hi Robert, >> >> We are not updating the data frame-to-frame, which is why this is so >> baffling. I'm working through the issue with gDebugger now - if you >> don't have any suggestions off the top of your head, then I'll start >> digging and report back what I find, since I don't have time try and >> duplicate the issue outside our app. >> >> cheers, >> >> sean >> _________________________________________________________ >> Sean Spicer >> Aqumin (www.aqumin.com) >> Office....+1.713.781.2121 >> Mobile...+1.713.447.2706 >> Fax.......+1.713.781.2123 >> >> >> >> On Fri, Dec 17, 2010 at 2:36 AM, Robert Osfield >> <[email protected]> wrote: >>> reproduces the problem you are seeing? >>> >> > _______________________________________________ > 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
