3DMark 99 Picture Comparison

Here are some 3DMark 99 Max screenshots featuring point sampling, bilinear, and trilinear filtering.

Point sampling

Bilinear filtering

Trilinear filtering

Anisotropic filtering

Notice the mip banding in the point sampling and bilinear pictures. It's not present in the trilinear shot.

Bilinear and trilinear filtering work best on polygons that directly face the viewer. Bilinear and trilinear filtering might cause polygons angled to viewer to lose detail because the choice of sampled pixels don't accurately reflect the angle and shape of the polygon. This can be seen when bilinear or trilinear filtering is applied to a texture containing text. If the texture is angled, the text will appeared blurred because the filtering method didn't choose the most accurate pixel formation to sample. Anisotrophic filtering models texels initially as ellipses instead of the traditional form of circles. This is supposed to make it sharper, especially for "edge on" text, but we haven't seen a good example of this yet.