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glBen
12-15-2009, 08:32 AM
Hello,

I need to to render a scene from multiple viewpoint at each time step and to readback the rendered images on the main memory.

Any idea on how to do it as fast as possible?

First guess would be to use one FBO for each viewpoint and a VBO for the scene and looping on all my viewpoint doing:
+FBO binding,
+Viewpoint setting,
+VBO rendering,
+FBO texture pixel read.

Does it look right or do you see a fastest way?

Thanks,

Ben

ZbuffeR
12-15-2009, 09:12 AM
+FBO texture pixel read. -> that would be a case were async PBO is useful.
http://www.songho.ca/opengl/gl_pbo.html

glBen
12-15-2009, 09:34 AM
OK. Thanks for the tips on async PBO. I'll look into that.

One other thing. Is there a way to readback the vertices and facets processed by the graphic card?

I explain myself a bit more: I would need to make a library where people just need to write their "draw" function and when launching the program it would create N views of their objects and an .iff or .obj file for each frame.

Thanks again for your help,

Benjamin