In 3D computer graphics, a micropolygon (or μ-polygon) is a polygon that is very small relative to the image being rendered.
[citation needed] The concept of micropolygons was developed within the Reyes algorithm, in which geometric primitives are tessellated at render time into a rectangular grid of tiny, four-sided polygons.
Shaders that operate on micropolygons can process an entire grid of them at once in SIMD fashion.
This often leads to faster shader execution, and allows shaders to compute spatial derivatives (e.g. for texture filtering) by comparing values at neighboring micropolygon vertices.
This displacement is usually not limited to the local surface normal but can be given an arbitrary direction.