Marcus Lindblom wrote: > Allen Bierbaum wrote: >> So my question is, is this how OpenSG/OpenGL are currently working or is >> there some way that we are avoiding this performance trap? >> > I don't know about OpenSG, but I've seen some info in slides on what > texture caching scheme the OpenGL-drivers are using, but I can't > remember what it said (sorry). One would hope it's not simple LRU, but > it could well be. Have you tried searching for opengl > performance-related presentations from GDC, NVidia, ATI etc? > > It should possible to test since performance ought to be different if > you rendered the objects in random order every frame (helping LRU, > defeating a smarter algorithm).
This posting describes what OSX does: http://lists.apple.com/archives/Mac-opengl/2001/Sep/msg00116.html They use a combination of LRU/MRU: "LRU is used up until the frame is over committed for texture resources. When this condition is detected the driver will switch to MRU. The driver will switch back to LRU at the beginning of each frame. This will prevent the LRU algorithm from paging through all of the textures in an over commit scene." This would work well for the case I outlined and would prevent the thrashing issue. -Allen > > Texture priority was mentioned as a way around this (to avoid swapping > out big textures that are used every frame anyway), but I don't know how > much it helps. > > Cheers, > /Marcus > > ------------------------------------------------------------------------- > Take Surveys. Earn Cash. Influence the Future of IT > Join SourceForge.net's Techsay panel and you'll get the chance to share your > opinions on IT & business topics through brief surveys-and earn cash > http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV > _______________________________________________ > Opensg-users mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/opensg-users > ------------------------------------------------------------------------- Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT & business topics through brief surveys-and earn cash http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV _______________________________________________ Opensg-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/opensg-users
