View Full Version : FBO texture rendering trouble

04-16-2009, 02:29 AM
Hi folks,

I have a weird problem with FBO textures that I hope someone can help me with.

I'm rendering some objects as impostors, and these impostors have FBO textures that are rendered into when the impostor needs an update.

Now, this seems to work OK, and my impostor textures look as they should. However, the contents of the impostor texture is also rendered to the screen, so I get flickering images of all the impostor nodes on the screen each time they are updated...

I have traced this in gDebugger and regular debuggers, and I really can't see that I do anything wrong here.. The FBO is bound and unbound correctly, I get no GL error messages or incomplete buffers.

The FBO textures are 32-bit RGBA textures with no depth buffer. Depth writes are disabled when rendering the impostors.

Anyone seen something like this before? It is probably something really stupid that I have forgot, but I'm at my wits end here....


04-16-2009, 07:49 AM
Anyone seen something like this before?
Yes, with OpenSG. No, with OpenGL and real FBOs.
Give card, driver version, OS and code.

04-17-2009, 08:35 AM
I figured it out, it was just a stupid bug on my part :-)

It turned out that the impostor wasn't rendered to the screen along with the FBO, it got rendered to screen right after, because the modelview and projection transforms weren't reset after the FBO rendering, *D'oh* :-). The next frame it got rendered OK because then the transforms were set correctly.

Sorry about the false alarm :-)

Cheers again