The renderer is a ray tracer, which means it simulates the physics of light by tracing the path of light rays around your scene. Each exciting chapter presents a bite-sized piece of the puzzle, building on earlier chapters and setting the stage for later ones. Requirements are given in plain English, which you translate into tests and code. When the project is complete, look back and realize you've built an entire system test-first! There's no research necessary — all the necessary formulas and algorithms are presented and illustrated right here. Dive into intriguing topics from fundamental concepts such as vectors and matrices; to the algorithms that simulate the intersection of light rays with spheres, planes, cubes, cylinders, and triangles; to geometric patterns such as checkers and rings. Lighting and shading effects, such as shadows and reflections, make your scenes come to life, and constructive solid geometry (CSG) enables you to combine your graphics primitives in simple ways to produce complex shapes. Play and experiment as you discover the fun of writing a ray tracer. Accept the challenge today!