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Multi-Sampling Anti-Aliasing Explained

Posted by timothy on from the make-your-brain-bigger dept.

Alan writes: "FiringSquad.com just posted a new article explaining how next-generation multi-sampling anti-aliasing works. They claim that it will bring us one step closer to anti-aliasing without a performance hit, and that the technology is going to be implemented in one of the new chips coming out? (NV20 anyone?). It's pretty technical, so only hard-core techies need apply. The link is over here."

2 of 125 comments (clear)

  1. Patents by Bruce+Perens · · Score: 5
    Pixar has a patent on the stochastic dither multi-sample antialias. They've enforced it before.

    Bruce

    --
    Bruce Perens.
  2. Please mod that misinformation down! by mc6809e · · Score: 5
    "Just as a point of interest, and education:"

    Before you try to educate someone else, start with yourself! The light/dark pattern thats seen with the experiment you describe is nothing more than an interference pattern created when the monochromatic and coherent light reflects off the surface of the object you're looking at and strikes your retina.

    For a more complete description, take a look at:

    http://www.repairfaq.org/sam/laserioi.htm#ioiscs0

    Now, as far as eye resolution goes:

    "For an eye with 20/20 vision, the angular resolution is 1 arcminute (1/60th of a degree)"

    With this information, we can make a good guess at what a monitors resolution "ought" to be.

    Take the sine of 1/60&#186 and multiply this by the aproximate distance from the monitor.

    At 3 feet, you get about 0.0105 inches. So you need about 100 pixels per inch. Thats 10,000 per square inch.

    A 17" monitor is about 13"x10", so a resolution of 1300x1000 should do the trick at 3 feet.

    Also, notice the qualifications I made

    A 17" monitor...

    ...at 3 feet.

    This shows that the statement: "The human eye can see aliasing artifacts at resolution up to and even beyond 4000x4000, so obviously 1600x1200 is not sufficient.

    is meaningless without knowing the viewing distance.

    But even knowing the viewing distance still gets us no where. Notice the ought above in quotes. No matter what the resolution of the monitor, there exists textures that will cause aliasing unless other steps are taken. Outline of a proof:

    1) Cast one ray from the virtual eye (POV) through each pixel of the screen onto a surface parallel to the screen, but some distance away in the virtual world.

    2) Where the cast rays meet the surface, find the texture element of the surface at this intersection and color it white.

    3) Color the rest of the texture elements black.

    It should be obvious that the surface viewed at this distance with this texture and without anti-aliasing will appear totally white. It should also be obvious that for any resolution we can create a texture that will cause this effect.