o220o wrote:
- anisotropy filtering clears up images...this one is
- a bit harder to explain...ummm, in games some images
- appear blurry when they are farther
- away...anisotropy filtering sharpens the image
- making it more defined and legible...
Actually, not quite. It's for smoothing the demarcations between levels of mipmaps. What's a mipmap? Well the textures you see in the game (what makes it look like stone or grass or whatever) are basically flat patterns that are stretched over the frame of the model. Up close, these need to be pretty detailed to look good. Far away, they don't need so much detail. So you've either got to make a few different detail levels or be able to make one texture file and reduce the quality in software - the point of all this being to reduce memory use on the graphics side. Where anisotropic filtering comes in has to do with where you go from one level of detail to the next.
Say you're looking down a hallway that has four mipmap levels. With no filtering (or cheap filtering), you will be able to see lines along the walls where it goes from one level of detail to the next the farther away from you it gets. The anisotropic filtering basically overlaps and blends the levels so there is no sharp line between the two. Depending on the mode (bilinear, trilinear, etc), as to the quality of the image.
That would be it in a nutshell. For a picture and article with full explanation, visit your local library and find the June 2003 issue of Maximum PC.
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