[osg-users] Techniques to shift CPU load to GPU

[David Heitbrink]

This is a pretty broad topic. It largely depends on what you are trying to display. 

If you are displaying a lot of the same thing, (say a warehouse filled with 1000's of identical boxes) you can use hardware instancing, there are a of sources you can look up on the subject. The OSG forest example is pretty good. This is a pretty good link:

http://3dcgtutorials.blogspot.com/2013/08/instancing-with-openscenegraph.html

 The osg GPU Cull example is a bit more complicated example, but pretty good, but this also depends on displaying a lot of the same thing. 

You can look at tessellation and geometry shaders and what can be done with those.  

Other things you may look at are simpler like combining geometries. If you have 1000's of objects with with a handful of triangles each, combining them into a single primitive set can help a lot. You may need to use a texture atlas to get this done. 

Simply drawling less stuff, by using occlusion nodes can help a lot.  

These may or may not be applicable for you depending on your scene. Whats in your scene-graph? How is it being updated every frame. Is it a static scene, are you manipulating a lot meshes every frame? 

Overall this is really broad, and some of it can get complicated fast. Without knowing what you are trying to do it is really hard to give any meaningful advice.

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Read this topic online here:
http://forum.openscenegraph.org/viewtopic.php?p=67148#67148