Alpha to coverage is a multisampling computer graphics technique, that replaces alpha blending with a coverage mask. This achieves order-independent transparency for when anti-aliasing or semi-transparent textures are used. This particular technique is useful for situations where dense foliage or grass must be rendered in a video game.
Alpha to coverage multisampling is based on regular multisampling, except that the alpha coverage mask is ANDed with the multisample mask. Alpha-to-coverage converts the alpha component output from the pixel shader to a coverage mask. When the multisampling is applied each output fragment gets a transparency of 0 or 1 depending on alpha coverage and the multisampling result.
See also
External links
- GPU Gems 3 ‒ Chapter 4. Next-Generation SpeedTree Rendering
- Street Fighter IV PC explained in detail
References
Golus, Ben (21 October 2021). "Anti-aliased Alpha Test: The Esoteric Alpha To Coverage". Medium.[better source needed] https://bgolus.medium.com/anti-aliased-alpha-test-the-esoteric-alpha-to-coverage-8b177335ae4f ↩
"Alpha to coverage | Semantic Scholar". https://www.semanticscholar.org/topic/Alpha-to-coverage/2037914 ↩
"Common Rendering Mistakes: How to Find Them and How to Fix Them | Oculus". https://developer.oculus.com/blog/common-rendering-mistakes-how-to-find-them-and-how-to-fix-them/?locale=es_ES ↩
"Configuring Blending Functionality (Windows)". Microsoft Developer Network. Retrieved 2013-01-27. Alpha-to-coverage is a multisampling technique that is most useful for situations such as dense foliage where there are several overlapping polygons that use alpha transparency to define edges within the surface http://msdn.microsoft.com/en-us/library/windows/desktop/bb205072%28v=vs.85%29.aspx#Alpha_To_Coverage ↩