I’m having some problems with occlusion query on ATI board that I hope you can help me with.
I’m rendering to a FBO, and using a occlusion query to determine how many pixels are going to visible for each object. The objects are rendered front-to-back with blending enabled. I have enabled alpha testing when rendering the occlusion queries. My occlusion query always returns 0 if I do not disable depth test! This is pretty strange as the FBO does not have a depth buffer attached. Has anyone run into similar problems on ATI.
The code fails on FireGL v7100, and FireGL v7340 - but runs perfectly on NVIDIA (GeForce 6800 GTX, GeForce 7900 GTX, and GeForce 8800 GTX).