3D Graphics Programming with QuickDraw 3D 1.5.4

Using Trigrids

The trigrid format has a fixed topology, defined by the numbers of its rows and columns. As a result, memory and file space is very efficiently used and I/O and rendering speeds are fast. However, the trigrid's fixed topology and the fact that shared locations must share attributes restrict its generality and flexibility.

The trigrid format is good for representing objects that are topologically rectangular--for example, surfaces of revolution, swept surfaces, and terrain models. It is also useful as an output primitive for applications that need to decompose their own parametric or implicit surfaces. In such applications the trigrid can be an especially good choice because it's more space efficient than the other polyhedral primitives.