Jaton 3DForceS-128, Руководство пользователя

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displayed the same image at 400*400 pixels you will see larger
and larger blocks of pixels of the same color. This is what
would happen with a 3D object when you move closer to it in a
game if there was no techniques of filtering.
Filtering is a technique for smoothing textures mapped onto 3D
objects. When the filtering is used, the color of each pixel of
the destination texture is determined by performing linear
interpolations between the colors of several pixels inside the
source texture. Following are some methods of filtering starting
(from the worst quality to best)
1. Point Sampled filtering: Point filtering will just copy the
color of the nearest real pixel, so it will actually enlarge the
real pixel. This creates a blocky effect and when moving
this blocks can change color quickly creating weird visual
effects. This technique is always used in software 3D
engines because it requires very little calculation power.
2. Bilinear filtering: When this technique of filtering is used,
the color of each pixel in the destination texture is
determined as a weighted average of the colors of the four
adjacent (up, down, left and right) pixels inside the source
texture. The disadvantage of bilinear texturing is that it
results in a fourfold increase in texture memory bandwidth.
3. Trilinear filtering: Trilinear filtering is a combination of
MIP-mapping and Bilinear filtering. In trilinear filtering the
two versions of a source texture corresponding to the
adjacent levels of detail are selected. Then, bilinear
filtering is used in each version of the source texture.
Finally, the colors of the two pixels produced by bilinear
filtering are blended together. With this method of
filtering, eight pixels are used to determine the color of the
destination pixel.
4. Anistropic Filtering addresses quadrilateral shaped and
angled areas of a texture image. A sharper image is