Final Thoughts

This article was designed to give you a quick overview and example of two more uses of the FBO extension.

The first example allows you to use the same FBO to render to multiple textures without switching FBOs, this is a useful thing to know because while FBOs are light to change when compared to pbuffers it is still much quicker to switch render targets than to switch between FBOs. As such if you can group your textures which need to be rendered to one at a time in such a way you can save some time.

The second example was to give you a feel for MRT rendering. While the example here is somewhat trivial, MRT does form a major part of various render-to-vertex buffer and post-processing techniques, as such the ability to output to multiple colour buffers is a useful one to know.

As before more details can be found in the Framebuffer Object spec and the Draw Buffers spec. More OpenGL Game Programming also has a chapter on FBOs and a chapter on GLSL, written by myself, which touches on using FBOs and MRT with GLSL some more.

Notes on the example program

The example program requires some form of GLUT to be compiled and run (I used FreeGLUT)

References

More OpenGL Game Programming
Framebuffer Object Spec
GDC 2005 Framebuffer Object pdf