Animation is a visual technique that creates the illusion of motion, rather than recording motion through live action. The technique is used mainly for motion pictures. Animation can be created by illustrators, filmmakers, video makers, and computer specialists. Animation is most popular in creating cartoon movies. Advertisers also employ animation to develop commercials for television. In addition, producers of instructional films may use animation to help explain a difficult idea or one that could not be shown in live action. Animation can also be combined with live action in a movie. Many animators continue to make many drawings by hand. Since the mid-1980's, however, computer assistance combined with hand-drawn animation has become standard in many movie studios. These methods created such feature-length animated films as The Lion King (1994) and The Prince of Egypt (1998).
One increasingly important type of animation is computer-generated imagery (CGI), in which the computer creates the characters and backgrounds and animates them without actually photographing either cels or figures. Films made entirely with CGI include Toy Story (1995), Antz (1998), and A Bug's Life (1998).
Most CGI-animated characters start with a sketch or small sculpture called a "maquette" that is used for reference. The artist then creates a computer image called a wireframe model. The wireframe model serves as a framework for a shell or skin that gives the computer image a solid, three-dimensional appearance.
To move the character, a computer animator changes the positions of the wireframe model in a number of key frames. The computer then supplies the frames between the key frames, moving the model from one of the animator's positions to the next.
After creating the three-dimensional model, the artist adds color, texture, and shading in a process known as texture mapping. Texture mapping makes the surfaces of the characters and scenery look real. A...