I've decided to go ahead with a part-2 on the mini-book

The mini-book Ray Tracing in One Weekend got more interest than I expected.   Apparently ray tracing really is hot.   The book just gets a brute force path tracer with spheres up, so I decided it would be worth making a part 2 (to be written!).   I am seeking comments on what is missing from the list.   Here is my first cut:

Chapter 1: Motion Blur
Chapter 2: A Bounding Volume Hierarchy (BVH) Chapter 3: Solid Texture Mapping Chapter 4: Image Texture Mapping
Chapter 5: Volumes Chapter 6: A Polished Material Chapter 7: Environment Maps Chapter 8: Shadow Rays Chapter 9: Triangle Meshes


I would consider that a full-featured ray tracer.   That is not to say having all features!