Anisotropic map

= Anisotropic Map = A texture that controls the shape of the specular highlights from real-time lights, often used for hair shading.

The texture is very similar in concept to a NormalMap, except instead of controlling surface normals, it stretches the specular highlight in specific directions across the surface.

Anisotropic Tutorials

 * http://stephenjameson.com/tutorials/anisotropic-shader-for-hair/Anisotropic Shader For Hair by Stephen Jameson provides a breakdown of a shader setup in the Unreal Development Kit (UDK).
 * HAIR!? thread on Polycount by Paul 'Prolow' Lohman has some examples of an anisotropic hair shader in Maya.