This project is just a simple extension of Homework 7 where we make the
bouncing of rays recursive. Now when we shoot out a ray and it hit's
something we shoot out a random another random ray as before, but if it
hits something we continue shooting out rays until we reach some maximum
number of bounces or don't hit anything. It is this recursive tracing
of a path to a light which creates the more realistic shading. The
following two pictures are path traced. Notice in the second picture
how the color of the blue floor is reflected from the bottom of the sphere.
This behavior is not evident in the previous assignment because any ray
bouncing off the bottom of the sphere is just "looking" for a light source,
whereas here a ray can bounce off the bottom half of the sphere, hit the
ground plane, and then hit a light source making that point on the sphere
have a bluish tint.
Figure 1 - Same as figure 2 in previous assignment. 1600
samples per pixel.
Figure 2 - White sphere on a blue plane. Note how the bottom side
of the sphere turns a tint of blue because of the reflection off the ground.
