I am a bit confused of the difference between transparency/alpha blending and alpha-to-coverage, since Frank D. Luna put both techniques in one section of 3D Game Programming with DirectX 11, letting it appear that the latter technique is superior. I have some questions:
I guess the superiorness is only related to the smoothing of blocky edges and not to the handling of transparency?
Since the alpha in alpha-to-coverage technique is used as coverage instead of the coverage determined at the polygon level:
should opaque geometry be rendered without alpha-to-coverage, since we will otherwise have always 100% coverage (killing the purpose of MSAA in the first place)?
do you loose quality for transparent geometry (which have a texture with an alpha channel), since the coverage determined at the polygon level is not used? (as opposed to MSAA with alpha blending)
Transparency/alpha blending requires sorting and rendering back-to-front.
Is this the case for alpha-to-coverage as well?
Suppose the alpha of a fragment is 50%, what happens with the source (fragment) and destination color? Is there still some kind of blending with the background or is the color intensity reduced by half?
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