Triangle fan

A triangle fan is a primitive in 3D computer graphics that saves on storage and processing time.

This is a considerable improvement over the 3N vertices that are necessary to describe the triangles separately.

The graphics pipeline can take advantage by only performing the viewing transformations and lighting calculations once per vertex.

While triangle fans were useful back then with flat shading or Gouraud shading objects without textures and limited RAM, today they cost performance with fragment shaders and multisampling rasterization.

[2] Any convex polygon may be triangulated as a single fan, by arbitrarily selecting any point inside it as the center.