> > apps can abuse this feature. If you issue a query and immediately > > block for the results, then yes, that will completely flush > the pipe.) > > I would expect the occlussion querry will be similiar to > glReadPixels as for both you have to flush the contents of > the OpenGL fifo in front OpenGL call to retrieving the > results, the only way to avoid this is to not querry for the > results time after most the frame has been drawn. If the > special effect that requires the pixel coverage count can be > drawn after then rest of the scene then potentially things > will might be doable within one frame.
The usual way this is ensured is to use the occlusion result from the previous frame in the next frame's rendering. This is easily done in apps with strong frame-to-frame coherency. -Paul _______________________________________________ osg-users mailing list [email protected] http://openscenegraph.net/mailman/listinfo/osg-users http://www.openscenegraph.org/
