So one child could hold information about one and the other child the other ray. There is a leaf when a ray reaches a light source or when we have reach the maximum preset depth. The intensity of a pixel is assigned by adding the intensity contribution from the leaf up to the root by following some rules which we will not discuss. As we can see before, rendering the scene, many computations are required for finding intersections. There are many ways to reduce this problem.
Some people try to reduce the time required for intersection testing.
Others use different ways than ray tracing. Others find a way to reduce the number of intersection tests needed. We will look at this last methods using BSP Tree. Consider a scene. We use a bounding volume to surround that scene.