Fsaa (fullsceneanti-aliasing) full screen anti-aliasing Technology

Introduction: Fullsceneanti-aliasing (fsaa) is a technology that can eliminate the Sawtooth image edge and make the image look smoother. This anti-aliasing technology is usually applied to 3D or text images. The main method is to perform an average operation on these pixels (pixel) at the edge of the image to achieve the smooth effect of the image, however, the disadvantage is that the image may be blurred. In this article Article Orderedgridsupersampling (ogss) and rotatedgridsupersampling (rgss) are two main technologies used to implement fsaa ). The so-called ogss is to zoom in and color the original screen, and then restore the screen to the original size and display it on the screen, in this way, the image will be removed from the image edge. Compared with ogss, rgss has a step of adjusting the sampling (jitter) to eliminate the Sawtooth. Category:

Full-screen anti-aliasing can be roughly divided into the following modes:
I. ssaa

Ssaa-Super sampling anti-sawtooth

It is difficult for the human eye to tell more than 300 dpi (DPI is short for "dot Per Inch. As the name suggests, it refers to the number of points in the length of each inch .) The preceding color points. That is to say, if the resolution of a display with a diagonal line of 15 inch is 3600 × 2700, there is no need for full anti-aliasing, because the human eyes cannot tell such fine points.

Supersampling anti-aliasing (supersampling anti-aliasing) is to multiply the current resolution (for example, the current resolution is 1024 × 768. After ssaa is enabled twice, the image is enlarged to 2048 × 1536 ), then scale the image to the current display. This is actually to increase the resolution when the display size remains unchanged, so that a single pixel becomes extremely small, which can greatly reduce the image's sawtooth. However, due to the enlargement of the entire display screen, it consumes a lot of display resources.
Ii. msaa

Msaa-Multi-sample anti-sawtooth

The principle of multisample anti-aliasing is the same as that of super sample. However, msaa searches for pixels at the edge of an object and then scales them. Because only the outer pixels of an object are scaled and the internal pixels that do not produce any serrations are ignored, the video card does not require a large amount of computation as ssaa is processed. Therefore, msaa is more effective than ssaa.
Iii. csaa

Csaa-overwrite sampling anti-sawtooth

Coveragesampling anti-aliasing. The principle is to overwrite the subpixel coordinates to be sampled in the edge polygon, and forcibly place the original pixel coordinates in hardware and drive.ProgramIn the coordinates of the prediction. This is like msaa, which has a unified sampling standard. It can perform Edge Sampling with the highest efficiency, greatly improving traffic, and reducing resource usage.
Iv. CFAA

CFAA-programmable Filtering

M filter anti-aliasing technology originated from the r600 family of AMD-ATI. In short, CFAA is the msaa that expands the sampling area. For example, the previous msaa strictly selects the edge pixels of the object for scaling, while CFAA can choose to scale the pixels that have a greater effect on the Sawtooth effect through the driver harmoniously and flexibly, in exchange for a smooth effect at a lower performance sacrifice. The usage of graphics card resources is also small.

Currently the most popular are csaa and CFAA, which should be the most practical and efficient full-screen anti-aliasing mode. They not only have good smooth effects, but also have low resource usage.

Additional reading:

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  Http://dev.gameres.com/Program/Visual/Other/fsaa.htm