The purpose of the midterm was for students to experiment with Cel Shading (aka "toon shading"), or a nonphotorealistic set of techniques for making rendered images appear as cartoons. Students experimented with quantized shading and Gooch shading, and they drew lines on back faces so the outlines of images would pop out.
Submissions (in no particular order)
Quantized shading + back face lines on the default scene provided in the assignment
Flat shading + back face lines on the default scene provided in the assignment.
Cool to warm (aka. Gooch Shading) on the default scene
Cool to warm (aka Gooch shading) on some spheres
Cool to warm + back face lines on Robotnik
The penguino gang with quantized shading + back face lines
A halloween scene using quantized shading + back face line drawing.
Thicker Lines, more quantization levels
Quantized cel shading + back face line drawing on the scene from mini assignment 2.
Quantized shading on the ray tracing default scene.
"Funky cel shading" (aka saturation bug when not dividing by number of quantization levels)