Computer Animation is the art of creating moving images via the use of computers. It is a subfield of computer graphics and animation. Increasingly it is created by means of 3D computer graphics, through 2D computer graphics are still widely used for low bandwidth and faster real time rendering needs. The common applications of computer animations are entertainment (computer games, motion picture and cartoons) advertising, scientific and engineering studies and training and education.
In computer animation to create the illusion of movement, an image is displayed on the computer screen, then quickly replaced by a new image that is similar to the previous image, but slightly shifted. This technique is identical to how the illusion of movement is achieved with television and motion pictures.
The various applications of computer animation are cartoons, advertisement, motion pictures, and some other entertainment or scientific and engineering studies. Animations are applying object motions. Therefore the team computer animation usually refers to any time sequence of visual changes in scene. Generally we see the animation in advertisement. There is a transition of one object shape into another for example transforming a car to a tiger. Computer animation are also be generated by changing the various parameter of camera; Also the computer animations are produced by changing lighting effects or other parameters and procedure of rendering and illuminations. Most of computer animations requires realistic displays. For the simulation the accuracy is more important whereas entertainment and advertising applications are more interested in visual effects.
There are three different kind of devices used to produce moving pictures: CRT screens in which pixels are rapidly changed, conventional movie projector, and LCD displays that are fast enough to serve as TV displays.
A film/movie projector is a device that continuously moves film along a path so that each picture frame of the film is stopped for a fraction of second in front of light source. The light source is a white light beam which provides extremely bright illumination that casts the image on the film through a lens onto a screen. During the change of one picture frame the next picture frame the light is temporarily blocked off. It is necessary to move the picture frames, at least 30 picture/second to visualize smooth animation.