Hey Dirk, thank you for this detailed answer.
>> How would you recommend to render an OpenSG geometry as a dynamic draw VBO? >> Is there a possibility to write a RenderAction? > >You wouldn't have to do that, it would be enough to change the Geometry. > ok, how far do you mean? What I have to do to let the geometry be rendered as dynamic vbo? > >But, with the current model you probably won't gain very much in doing that. As >OpenSG has very little control over which thread has an active OpenGL context, >it cannot use direct writing to gfx memory, so the Property will always go to >main memory first, which is then copied to gfx memory on draw. Changing that >would be a major effort, as you wouldn't be able to create Geometry before the >window is open and the context active, and you would only be able to create new >geometry in the OpenGL thread. > >On the other hand I've seen very contradictory performance results comparing >static and dynamic, so I'm not sure how much benefit it really gives. You >probably gain more by switching off bounding volume updates, if you change the >geometry for every frame. The thing is, I suppose, that dynamic drawn vbo's have benefits, if you often change the vertex properties. For example, if you want to animate a geometry every frame. But I'm not familiar with with OpenSG cluster rendering... so maybe if many nodes render one geometry, there is only a little performance difference between static and dynamic vbo's. > >What are you trying to do, what is your bottleneck? > I'm trying to deform a OpenSG geometry using NVIDA CUDA. If you want to change geometry data with CUDA and you do not want to copy the data from the cpu side ram to the gpu side ram and back again every frame, the only possibility is to access OpenGL Vbo's. Sven -- ------------------------------------------------------------------------- SF.Net email is sponsored by: Check out the new SourceForge.net Marketplace. It's the best place to buy or sell services for just about anything Open Source. http://ad.doubleclick.net/clk;164216239;13503038;w?http://sf.net/marketplace _______________________________________________ Opensg-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/opensg-users
