The Ray Tracer Challenge

Putting It Together

Okay. Take a look at the program you wrote at the end of the previous chapter, the one where you drew the silhouette of a sphere on a canvas. It’s time to revisit that and turn the silhouette into a full-on 3D rendering. Make the following changes to that program:

1. Assign a material to your sphere. The following material will give you a sphere that looks like the illustrations in this chapter.

   sphere.material ← material()
   sphere.material.color ← color(1, 0.2, 1)

2. Add a light source. Here’s one possible configuration, with a white light behind, above and to the left of the eye:

   light_position ← point(-10, 10, -10)
   light_color    ← color(1, 1, 1)
   light          ← point_light(light_position, light_color)

3. In the loop where you cast your ...