Quote:
Originally posted by meglamaniac
Anti-aliasing, not so much realtime on graphics cards (but it's getting there)
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AA is supported in real time by most 3d cards, however I suspect its not the same technique use by 'slow' renders as you find in modelling programs.
Most of the methods for rendering anti-aliased primitives (in OpenGL at least) rely on blending the primitives in sorted order (either back to front or front to back). Anti-aliased points and lines typically use a lookup table technique to compute the fraction of each pixel covered by the primitive. The coverage value is then used to determined an alpha value to be used in the blending computation. This is done as part of standard scan-line rendering, which is how most (not all) current 3D cards render.
There are also some alternatives. One of these is called the accumulation buffer (which I dont really know about). Another method is using super-sampling.
In super-sampling additional subpixel storage is maintained as part of the color, depth and stencil buffers. Instead of using alpha for coverage, coverage masks are computed to help maintain sub-pixel coverage information for all pixels. The implementations available so far support tow, four, eight, and sixteen samples per pixel. These sample values are probably what you are refering to when you say 'levels'. These are normally found under your cards video options as 2x,4x,8x,16x AA.