Hi Christian, VBO's are better for dynamic geometry, but do have a higher CPU overhead than display lists.
However, whether you are using VBO or not, you probably still don't want to modify any geometry. It's far more efficient to updating vertex position via vertex shaders. I know too little about your code to be specific, but as a general note that graphics hardware works best with state geometry and primitive sets and with relatively large batches of geometry sent together. Sending lots of indivual trees geometries is inefficient for both the GPU and the CPU. Robert. On Sun, Apr 5, 2009 at 12:11 PM, Christian Sam <[email protected]> wrote: > Hi, > > i have a question about using VBOs and Display Lists in osg > > according to my OpenGL book, both methods will optimize rendering due > geometry is moved to the graphics-hardware. it also says, a constraint when > using display lists is, that data can't be changed afterwards. so its great > for rendering the same object multiple times, but not when you want to > modify it. > > in my application i'm rendering a forest. i want to have a handful of > different tree sprites, which will vary in size and color (but not in > texture). as far as i know osg uses display lists by default - will i > benefit from a switch to vertex buffer objects, because in this case many > states will stay the same and only geometry will vary/be modifed through the > different tree sprites? > > > best regards, > christian > > ------------------ > Read this topic online here: > http://forum.openscenegraph.org/viewtopic.php?p=9755#9755 > > > > > > _______________________________________________ > osg-users mailing list > [email protected] > http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org >
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