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View Full Version : AMD Radeon HD 5770 + GL_SAMPLE_ALPHA_TO_ONE



Nicolas Lelong
04-28-2011, 03:25 AM
Hi,

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 ?

Thanks,

Nicolas.

NVidia result :
https://lh3.googleusercontent.com/_FKZbZxoRprE/Tbk_AYccvBI/AAAAAAAAABE/Z8c7lNJk_p8/s720/2011.04.28%20-%20GL_SAMPLE_ALPHA_TO_ONE%20NVidia.png

AMD result :
https://lh3.googleusercontent.com/_FKZbZxoRprE/Tbk_Af10q4I/AAAAAAAAABI/o69SWJ6Cpnw/s720/2011.04.28%20-%20GL_SAMPLE_ALPHA_TO_ONE%20ATI%20RadHD5770%20cat1 1.2.png