Ray tracing in a weekend springs to mind as being very approachable: http://www.realtimerendering.com/raytracing/Ray%20Tracing%20in%20a%20Weekend.pdf http://ww

Ray tracing in a weekend springs to mind as being very approachable: http://www.realtimerendering.com/raytracing/Ray%20Tracing%20in%20a%20Weekend.pdf http://www.realtimerendering.com/raytracing/Ray%20Tracing%20... I didn't do it in one weekend but managed to get through the material in a couple weekends ;)