Although computer animation becomes a newly rising visual transmit media of digital art just in past few years, this technology has ubiquitous and prominent influence in many application areas. In the beginning of this new century, many motion pictures have been made completely by using computer 3D animation, including special effects in movies, TV advertisements, computer games, TV sitcoms, even the movie “ Toy Story.” Due to these successful applications, computer animation technology has not only established new milestone in animation art but has also shown great potential for a number of extensive applications in the future.

As a new visual transmit media of digital art, computer animation technology keeps evolving constantly. Among components of animation, light always has been playing an important role. In animation world, a story can be told by changing lights only. For both simple and complicated scenarios, the emotion of audience can be manipulated effectively by appropriate control of lights. The audience will accept the plots easily in this way. In natural world, lights keep changing and have countless variations. How to use the easily controllable property of lights provided by most animation software in order to create natural lights which are different from real lights yet meet aesthetic standards accepted by most people is the major theme of this research.

This research focuses mainly on the studies of lights in animation. A short film entitled “ The Knife” has been produced as a case study. During the making process of this film, this research concludes the usages of lighting and analyses subtle difference of effects generated by various kinds of light sources to verify the relevant theory. Several suggestions then have been proposed to show that by precise control of lighting in an environment of computer animation, personal style can be demonstrated impressively even by telling an ordinary story.