a group at the University of Montreal; it featured a strikingly expressive human character, an aging piano player who entertained while inwardly reflecting on better days, which inspired the film. Apart from the film's hoped-for promotional value, Catmull and Smith rationalized the project as a test of "self-shadowing" in the rendering software- that is, the ability of objects to shed light and shadows on themselves. Before self-shadowing, CGI shadows were made by adding a flattened and darkened version of the shadowed object. On the technical level, the film demonstrates the use of shadow maps to simulate the shifting light and shadow given by the animated lamps. The lights and the color surfaces of all the objects are calculated, each using a RenderMan surface shader, not surface textures. The articulation of "limbs" is carefully coordinated, and power cords trail believably behind the moving lamps. Because time and money were tight, Lasseter reduced the setting to its simplest elements. The background would be plain black and there would be no camera movement. His energies would rather be focused instead on working out techniques based on classic animation principles to convey emotion. Even though the characters were faceless and wordless, Lasseter shaped such subtleties as the speed of the child's hops and the way it carried its head to convey in an instant when the child was feeling joy and when it was feeling sad. At every moment, the parent and child seemed to have a definite frame of mind. On the cinematic level, it demonstrates a simple and entertaining story, including effectively expressive individual characters. Catmull and Lasseter worked around the clock, and Lasseter even took a sleeping bag into work and slept under his desk, ready to work early the next morning. Release Luxo Jr., alongside Flags and Waves and Beach Chair, premiered at SIGGRAPH in the Dallas Convention Center Arena, where the audience of six thousand immediately recognized the short film as a breakthrough. Before Luxo Jr. finished playing at SIGGRAPH, the crowd had already risen in applause. "Pixar's marketing department did not go out of its way to point out that none of the film, not a single frame, had been rendered on a Pixar Image Computer", wrote David Price in his book The Pixar Touch. The audience was captivated by the far more realistic look than The Adventures of André and Wally B.. More significant than its photorealism,