Introduction

Triangles are unique as they are represented by three coplanar points. This means that a triangle will always be on a plane. This makes rendering triangles efficient, and it also makes collision detection of triangles efficient. The efficiency of triangles comes from the fact that many tests can assume that a triangle.

In this chapter, we are going to use triangles to represent a 3D model. This approach has one major limitation; we can only test for intersection, not containment. Testing for containment will require a convex hull. The convex hull will be briefly covered in Appendix, Advanced Topics.

The triangle primitive was covered in Chapter 7, 3D Primitive Shapes. This chapter will focus on intersection tests for triangles and building 3D models out of triangles.