David Brown. Photo by SAWhite.

Dr. Eugene Troubetskoy. Photo by SAWhite.

The essence of computer animation is making something that is fabricated look real. Artists and technicians in this field devote a considerable amount of time to analyzing which elements give objects and people their realistic appearance. Textures, movements, shading, and sound all have to be carefully designed to create convincing replicas. In the opinion of the executives and animators at Blue Sky Studios in Harrison, New York, light rays are the most important element for creating believable computer images. Their numerous commercials and recent feature film work demonstrate convincingly that understanding how light affects objects is essential to creating quality computer graphics.

Blue Sky Studios, Inc. was founded in February 1987 by a group of people who had met at MAGI/SynthaVision while they were working on Disney's TRON. Each brought a range of talents and experience that proved valuable in dealing with the emerging business of computer animation. David Brown, the company's current President and CEO, had been a marketing executive with CBS/Fox Video. Alison Brown (no relation), now Vice President of Marketing and Sales, came from advertising and special effects. The company's creative director, Chris Wedge, was an animation artist and teacher. The most unusual member of the group, and the man responsible for the distinctive look of its films, is Eugene Troubetzkoy, who holds a Ph.D. in theoretical physics from Columbia University. He and former NASA engineer Carl Ludwig developed the proprietary software and renderer that give Blue Sky its competitive edge.

The Physics of Animation
Troubetzkoy's approach to animation grew out of his earlier work in nuclear physics. Just as physicists study the way beams of electrons and photons bounce off other subatomic particles, Troubetzkoy analyzed how light rays interact with everyday objects. He and Ludwig studied how objects appear in a variety of lighting conditions, from bright to shaded, under clouds or under water, and looked at how they reflect or refract light rays. Using complex algorithms and over 50,000 lines of computer code, they wrote software that mimics these conditions in the computer.

The CG Braun shaver in question.

Blue Sky's trademark software CGI Studio also defines the material properties of an object--its density, transparency, and degree of reflectivity--and how these will be affected under different light conditions. When the company is working on a computer graphics project, technicians shoot a reference object, often a small white sphere, within the light environment that will be seen in the film, to study its illumination. Blue Sky's research team combines this information about light conditions with data on the material properties of the object to replicate how its surface would look under those conditions. The company's patented renderer, under the supervision of Carl Ludwig, then models that surface texture onto the animated object, in a process called ray tracing.

The result of the ray tracing process is high quality photorealism that even fools professionals. In a recent contest for computer animation, judges rejected a commercial that Blue Sky had produced for Braun's electric shaver, because they believed it had been shot on film. The surface texture of the metal object is so convincing, and the movements it makes so smooth, that it's easy to see how they were deceived.