ABSTRACT
This chapter covers basic methods for ray generation, ray intersection, and shading that are sufficient for implementing a simple demonstration ray tracer. For a really useful system, more efficient ray intersection techniques, the real potential of a ray tracer sees with the more advanced shading methods and the additional rendering techniques. Broadly speaking, image-order rendering is simpler to get working and more flexible in the effects that can be produced, and usually takes much more execution time to produce a comparable image. It explores the comparative strengths of the approaches. The chapter describes the most basic shading models. A ray tracer works by computing one pixel at a time, and for each pixel the basic task is to find the object that is seen at that pixel's position in the image. The particular object wants is the one that intersects the viewing ray nearest the camera, it blocks the view of any other objects behind it.
