Sphere in frustum

Now that we can get the view frustum of a camera, we will explore how to check primitives for intersection against the frustum. We will start by checking if a point or sphere intersects the frustum. This intersection test will also handle containment:

Getting ready

In this section, we are going to implement two intersection functions. The first function will test if a point is inside of a frustum. The second function will check if a sphere intersects a frustum. Both functions handle containment as well as intersection.

How to do it…

Follow these steps to implement intersection tests for a point and a sphere against a Frustum:

1. Declare the functions to test a point and a sphere against a frustum in Geometry3D.h:

   bool Intersects(const Frustum& f, const Point& p);
   bool Intersects(const Frustum& f, const Sphere& s);

2. Implement the point Intersects function in Geometry3D.cpp:

   bool Intersects(const Frustum& f, const Point& p) {
      for (int i = 0; i < 6; ++i)...