View Full Version : MRT on main framebuffer

03-19-2011, 02:35 PM
Hello everyone.

I have some quick question :

Is it posibble to attach to main framebuffers some extra color buffers. Fo example. Is that have any sense :


On main framebuffer ( no glBindFramebuffer used ).

If yes, do i have set up something more than just glDrawBuffers on many MRTs ?

Thank you.

Alfonse Reinheart
03-19-2011, 02:57 PM
No. You can only attach buffers to FBOs, not the default framebuffer.

03-20-2011, 09:45 AM
Ok, thak you. I rebuild all renderer to another FBO with MTR.

Some result: http://img822.imageshack.us/img822/3552/lightingr.png

I have one more question. What about performance. IS it ok to keep FBO with GL_TEXTURE_RECTANGLE_ARB or use regular TEXTURE_2D ones ?

03-20-2011, 02:45 PM
Framebuffer Objects allow the atatchment of rectangular textures without any issues. I can't say about perfomance comapared to NPOT textures however as I have never compared them. I find it much easier to use NPOT (matching the desktop resolution for example) rather than create a rectangular texture and have to enable/disable the GL state.

I would be interesting to hear other peoples experience in this area.

03-23-2011, 04:46 AM
I did some stress tests with different NPOT and POT textures as a sruface for FBO. My results :

NPOT is over twice faster than POT for resolution npot:1366-768 / pot:2049-1024.

Alfonse Reinheart
03-23-2011, 01:27 PM
NPOT is over twice faster than POT for resolution npot:1366-768 / pot:2049-1024.

What do those numbers mean?