Raytracing
In this part, we switch from real-time rendering in OpenGL back to offline rendering, this time using ray tracing. Ray tracing is a slower but more pure form of rendering that is able to more accurately model a number of real-world illumination phenomena. As such, the topic of ray tracing is a good medium through which to explore the concept of illumination more deeply. We’ll also take a closer look at some graphics math and geometry.