Animation 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 cell 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 wire frame model.

The wire frame 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 wire frame 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 texture map can be created by a computer program or scanned from an actual photograph.

The final step is called rendering. During rendering, the computer calculates the effect of light, color, and texture on the model's surface. For a film or video, the computer will produce a two-dimensional digital picture of the characters for each frame of the animation. The computer artist usually adjusts many visual effects, such as camera focus and transparency, during the rendering phase.

Some computer programs enable the artist to 'paint' color directly on the three-dimensional model. A single animation may take hours or even weeks to render. For example, six powerful computers took 24 hours to render a single second of some scenes from A Bug's Life. Computer-generated characters can be combined with live action in a process known as compositing. The science fiction film Jurassic Park (1993) popularized this technique when it combined realistic, computer-generated dinosaurs with actual actors and sets. Compositing can also be used to combine real actors with computer-generated sets and special effects.