Different between Renderbuffer and Texture?

[will mi]

As show in Framebuffer Detailed Description:

In addition to Textures, Renderbuffers may also be bound to the
Framebuffer. This is done in a very similar manner to the Texture
object in the example. Renderbuffer class contains an example of this
operation.

What's the different between Renderbuffer and Texture, as they both
exist on GPU.

If each Renderbuffer correspond to one opengl buffer, and how can I
use Renderbuffer back on CPU?
Use glMapBuffer and read?

[Tim Čas]

"What's the different between Renderbuffer and Texture, as they both
exist on GPU."

Renderbuffers are used as stencil, depth, etc... buffers, while textures are just that - pixel data containing color (and possibly alpha) values.

[Corey Taylor]

This does a pretty good job of explaning the restrictions and setup of FBO's with textures and/or renderbuffer.

 

http://www.opengl.org/wiki/Framebuffer_Objects

 

You should be able to access a renderbuffer with the standard pixel read functions.

 

Morgan probably has some performance advice for FBO use.

 

corey