The image shown on the class web page is an example of photorealistic rendering of a scene using a method called ray-tracing.
The model consists of a set of reflective balls placed on top of a flat square surface textured using a checker-board pattern. The entire scene has been placed within a large ball, which has been colored with a pattern called a gradient, which slowly varies from one shade to another. If you look closely at the reflection of the checkerboard pattern in some of the balls, you will notice a certain "speckly" appearance (especially for checkerboard squares that are far away). This is due to sampling effects called aliasing. It can be removed by a process called anti-aliasing.
