ABSTRACT
This chapter discusses some fancier techniques that can be used to ray-trace a wider variety of scenes and to include a wider variety of effects. Some extensions allow more general geometry: instancing and constructive solid geometry are two ways to make models more complex with minimal complexity added to the program. Other extensions add to the range of materials can handle: refraction through transparent materials, like glass and water, and glossy reflections on a variety of surfaces are essential for realism in many scenes. The chapter also discusses the general framework of distribution ray tracing, a powerful extension to the basic ray-tracing idea in which multiple random rays are sent through each pixel in an image to produce images with smooth edges and to simply and elegantly produce a wide range of effects from soft shadows to camera depth-of-field.
