A triangle fan is a primitive in 3D computer graphics

Computer graphics

Computer graphics are graphics created using computers and, more generally, the representation and manipulation of image data by a computer with help from specialized software and hardware....

 that saves on storage and processing time. It describes a set of connected triangles that share one central vertex (unlike the triangle strip

Triangle Strip

A triangle strip is a series of connected triangles, sharing vertices, allowing for faster rendering and more efficient memory usage for computer graphics. They are optimized on most graphics cards, making them the most efficient way of describing an object. There are two primary reasons to use...

 that connects the next vertex point to the last two used vertices to form a triangle). If N is the number of triangles in the fan, the number of vertices describing it is N+2. This is a considerable improvement over the 3N vertices that are necessary to describe the triangles separately. The graphics pipeline

Graphics pipeline

In 3D computer graphics, the terms graphics pipeline or rendering pipeline most commonly refers to the current state of the art method of rasterization-based rendering as supported by commodity graphics hardware. The graphics pipeline typically accepts some representation of a three-dimensional...

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

Any convex polygon

Convex polygon

In geometry, a polygon can be either convex or concave .- Convex polygons :A convex polygon is a simple polygon whose interior is a convex set...

 or Star polygon may be triangulated as a single fan, by arbitrarily selecting one vertex as the center.