Ulrich Hertlein wrote: > Hi Eduard, > > On 28/09/10 6:08 , Eduard - Gabriel Munteanu wrote: > > > I've been investigating an issue in Flightgear, an OSS flight sim using > > OSG. We have lots of stutter, usually in multiplayer, caused by loading > > new models (this happens whenever somebody join). Loading textures from > > disk happens on another thread (via DatabasePager), but I traced the > > issue to glTexImage2D() calls. So it's texture uploading to graphics > > driver / card that's causing it. It's not uncommon to see delays of > > 300ms for 500KiB - 1MiB textures. > > > > Did you try to enable object pre-compiling on the DatabasePager thread via > 'DatabasePager::setDoPreCompile(true)'? > > /ulrich > >
Thanks for your reply and sorry for the delay, I've been a bit busy. Yes, I tried setting precompiling on through both environment variables and code. It didn't help. :( Here's some more information. I'm using OSG from SVN revision 11785 (quite recent) on a Linux system, although other 2.9.x releases I tried exhibit the same problem. I use the latest Catalyst drivers for my graphics card. My hunch is somehow the card/driver doesn't like the pixel format in those textures and it's doing some internal conversions (e.g. RGB -> RGBA). Geometry data doesn't seem to be a bottleneck here, and I'm not sure if precompiling helps at all. So if I could make use of PBOs, DMA and loading would happen asynchronously and the problem would go away. I don't mind if those parts of the scene graph get rendered 5-10 seconds later as long as it doesn't cause stutter. It would also remove any smaller stutters and improve framerate. On the other hand, I can't really go and "fix" up all textures in the data tree, even if there was a format that could improve the situation. Any thoughts on how to get this done? ------------------ Read this topic online here: http://forum.openscenegraph.org/viewtopic.php?p=32513#32513 _______________________________________________ osg-users mailing list [email protected] http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
