The Anisotropic shader creates surfaces with elliptical, "anisotropic" highlights. These highlights are good for modeling hair, glass, or brushed metal. The basic parameters are similar to those for , except for the Specular Highlight parameters, and Diffuse Level controls such as those for .
Anisotropic highlights are elliptical, with differing U and V dimensions.
Anisotropy measures the difference between sizes of the highlight as seen from two perpendicular directions. When anisotropy is 0, there is no difference at all. The highlight is circular, as in Blinn or Phong shading. When anisotropy is 100, the difference is at its maximum. In one direction the highlight is very sharp; in the other direction it is controlled solely by Glossiness.