Opacity, Light and Animation

This chapter describes more thoroughly how the common goal of believability that drove the development of computer graphics was pursued, and which characteristics were part of this common goal. As the chapter title suggests, the primary objective was to create images that depicted objects not as line drawings, but as opaque objects. An additional aim was that these opaque objects could react to light, i.e. be lit and throw shadows, while an even greater believability of these synthetic images would, according to the developers’ beliefs, be achieved when one could move around these objects or have them be moved or animated . By the end of this chapter, a line has been drawn from the chapter on Sutherland to Pixar&s;s cofounder Edwin Catmull, demonstrating how certain beliefs about imaging as well as computing linger on until today. The sections are thus not only devoted to Edwin Catmull, who comes last, but also to Gordon W. Romney, Henri Gouraud, Bui Tuong Phong and James F. Blinn.