Alpha to coverage
Alpha to coverage is an anti-aliasing technology that allows alpha blending - textures , such as fences or vegetation to render .
Some of the textures in modern video games require alpha textures , such as those used to depict vegetation or fences. The normal antialiasing, also called edge antialiasing, cannot be used for the alpha textures, which results in the problem of edge flicker. This can only be prevented with transparent antialiasing. One possibility of transparent anti-aliasing was previously supersampling (SSAA), but this is considered extremely computationally heavy. Since, in the sense of full-scene anti-aliasing (FSAA), textures are also captured and output scaled down , the texture quality also increases.
Alpha-To-Coverage enables anti-aliasing to capture these alpha textures and smooth them at a relatively high speed. In addition, there is the problem that modern games mostly off-screen - Buffer use and thus AA is more difficult.
technology
This method uses the alpha channel of textures as a coverage mask for anti-aliasing. Alpha to Coverage Multisampling is based on regular multisampling with the exception that the Alpha Coverage Mask is linked to the Multisample Mask. Alpha to Coverage converts the alpha component output from the Pixel Shader to a coverage mask. When multisampling is used, each output fragment has a transparency of 0 or 1, depending on the alpha coverage and multisampling result.
Individual evidence
- ↑ GPU Programming Guide (PDF file; 1.8 MB)