Anisotropic Filtering

Anisotropic filtering attempts to provide texture clarity when viewed at extreme angles. When textures are applied, they are designed to be seen head-on by the camera. When viewed at angles, the proportion of the texture mapped to the surface of an object can become distorted and blurry. Anisotropic filtering, at the cost of VRAM, can provide clarity to these obliquely-observed surfaces.

Other solutions, such as bilinear and trilinear filtering attempt to correct the same issues as Anisotropic, but are not as effective. See example below.