I don't have experience with true OpenGL instancing. But... the last pseudo-instanced renderer I worked on was based on the osgforest osg sample. It even runs on outdated Intel GMA 945 chipsets, using ARB fragment shaders performing the dynamic repositioning of the geometry. The osgforest sample currently has a billboard geometry, but changing that to display cubes wouldn't be so difficult. Drawing 10000 billboards isn't much of a problem with this code.
The displacement for the coordinates is passed to the shader as glColor() which is a quick but efficient hack. There are many more openGL states that you could abuse if you need color support. Of course using the ARB's ProgramEnvParameter/ProgramLocalParameter API would also be an option. I think glColor() was chosen because it might be more efficient than a ProgramLocalParameter. A more self contained version of this billboard renderer is in my osgrvo2 code sample that I submitted to osg-submissions recently. It properly checks for availability of the required ARB extensions. Christian _______________________________________________ osg-users mailing list [email protected] http://lists.openscenegraph.org/listinfo.cgi/osg-users-openscenegraph.org
