ABSTRACT
When you render images of three-dimensional models, the models should not only have the proper geometrical shape, they should also have the desired visual appearance. In many cases (but not all-see Chapter 11) the goal is photorealism-an appearance very close to photographs of real objects. To reach this goal, it is worthwhile to use reality as our guide. This chapter first discusses some of the ways in which light and materials behave in the real world. A simple lighting and surface model is used as an example of how such models can be implemented by using programmable shaders.
