Geometric primitives

Geometric primitives are essential in the creation of the sophisticated objects seen in computer graphics. They provide uniformity and standardization in addition to making hardware support possible. Initially, the definition of geometric primitives was driven by either its general applicability to a broad range of needs or its satisfying ad hoc but useful applications. The triangular facet is, for example, simple to generate, easy to support in hardware, and widely used. An example of a specific primitive is “light strings” which are instances of variable-intensity, directional points of light used to simulate airport lights. This primitive is not common, but it is supported by a critical and profitable application, flight simulation. As hardware increased in capability, the sophistication of the primitives grew. Software primitives have become more common, although for speed, hardware still dominates. Initially, primitives were discrete or first-order approximations of objects; that is points, lines, and planar polygons. These were extended to higher-order primitives by polynomial or rational curves and surfaces. The following are examples of prevailing geometric primitives.