Notes on efficient ray tracing

There are many ways to make your ray tracer faster. If you're writing an interactive ray tracer, you've got to turn to your bottlenecks in your code and make them scream. You're probably spending the majority of your time computing ray-scene intersections (in some applications, ray-scene intersection may not be the bottleneck, for example Perlin noise is commonly a performance bottleneck for applications that use it heavily). To speed up ray-scene intersections, you use acceleration structures, but how do you get that extra factor of two in performance? This document is some informal notes on experience we've had at Utah on this topic. I do not include citations here. For the sources of these techniques see the bibliography for the chapters from the second edition of Fundamentals of Computer Graphics included in these notes. Several papers discussing these techniques are also included in these notes.