Anisotropic Shading

A type of shading used for surfaces with directional reflection patterns. It simulates how light reflects differently based on the surface’s microscopic grooves or fibers.A concrete example of anisotropy is brushed metal, such as the surface of a stainless steel kitchen appliance or a metal watch face. When light hits brushed metal, it doesn’t reflect uniformly like it would on a smooth mirror. Instead, the reflection appears stretched or directional, following the fine grooves created by the brushing process.In 3D rendering, to achieve this effect, an anisotropic shader is used. It mimics how light behaves differently depending on the orientation of these grooves. For instance, if you look at the surface from different angles, the highlights shift and stretch along the direction of the brushing, creating that characteristic “combed” or elongated shine. This anisotropic reflection is essential for accurately rendering materials like brushed metal, hair, fabrics like satin, or even the grooves on a vinyl record.