I'm using Catalyst 11.2 under Win7-64, and I'm trying to create 'imposters' with proper alpha channel by using render to texture and alpha-to-coverage.

To have a proper alpha channel value, I enable 'GL_SAMPLE_ALPHA_TO_ONE', which works as expected with an NVidia board, but not on AMD.

I also noticed that on AMD there's not more dithering applied for 'alpha to coverage'.

Does anyone have recommendations or workarounds to share for AMD and sample coverage ?



NVidia result :

AMD result :