i render my scene to FBO1 with multisampled renderbuffers, blit FBO1 to FBO2(with GL_TEXTURE_2D as storage) to downsample, and finally render a fullscreen quad to the framebuffer with FBO2’s texture.
This works nicely on Nvidia 8800Gt. On Ati X3850, it works basically too, but i get random white flimmering pixels at some multisampled edges.
As long as long as the objects remain static, the white pixels stay at the same position. When i change the modelview slighty, they appear at other random locations, but only at the multisampled regions.
Here an image of some frames with slightly changed positions:
My implementation is based on this:
- I tried Catalyst 8.8 and 8.12 and a few driver settings(catalyst ai etc), but nothing changed.
- Tried 16bit-float and 8bit backbuffers => no change
- Tried a different X3850, behaves the same
- When i do glReadpixels of FBO2 after blitting, i see the artifacts already
- When i set numSamples to 0 when creating the renderBuffers of FBO1, everything is ok(but no smoothing then of course)
What might be the cause?
Any idea for a solution/workaround?