Hi Terry, On 24 January 2013 18:21, Terry Welsh <[email protected]> wrote: > Mathias's point that display lists are deprecated are probably the > best reason to try to make the switch.
I'm of this view as well, and would go further and say now that modern graphics developers are working across a wider range of platforms - OpenGL ES and OpenGL and targeting shader pipelines with other modern features in the mix for the these developers using the same features across all the platforms is advantageous, VBO's are very much part of this mix of modern feature spread across targets while display lists are very much a hang up old systems. > If OSG isn't close to a major > release, I suggest trying it and seeing if it causes problems. Once I get some time to experiment I will have a play with different datasets and see how I get on. I think we'll need to beef up the Optimizer to make sure it handles things better. Also plugins also need updating to create more VBO friendly meshes. To do the job properly we have to take this all into account, I don't feel just switching the default is acceptable as it'll lead to some odd performance drops. > As for big vs. small geometries, I used to see differences as well. > Years ago, my rule of thumb was to make geometries with fewer than 200 > vertices use display lists and bigger ones use VBOs. I just tested > this again this morning on NVidia and Intel graphics and I see no > difference anymore. However, I'm using a practical test scenario that > runs through a scene in my game with geometries ranging in size from > about 20 to 1000 vertices. I'm not doing a contrived test. My test > scene is about 10% faster using all VBOs vs. all display lists. For modern scene graphs it's likely that VBO's will be strongest, but older scene graphs built with triangle strips and small clumps of geometry will prefer display lists - think OpenFlight databases for an example where display lists will be strongest. Robert. _______________________________________________ osg-users mailing list [email protected] http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
