Computer animation is the process used to generate animated images. The more general term of computer generated images (CGI) encompasses static and dynamic images, while computer animation refers only to moving images. Modern computer animation usually uses 3D computer graphics, although 2D computer graphics are still used for stylistic, low-bandwidth, and faster rendering in real-time. Sometimes, the purpose of the animation is the computer itself, but sometimes the film too.
Computer animation is essentially a digital successor to stop motion techniques that use 3D models and traditional animation techniques that use frame-by-frame animations to 2D artwork. Computer generated animations are more controllable than other more physically based processes, building thumbnails for effects shots or extras that employ for crowd scenes, and because it allows the creation of images that would not be feasible to use any other technology. It can also allow a single graphic artist to produce such content without the use of actors, costly fixed parts or accessories. To create the motion illusion, an image is displayed on the computer monitor and is repeatedly replaced by a new image that is similar to it, but progressed slightly over time (usually at a speed of 24 or 30 frames / second). This technique is identical to how the illusion of motion is achieved with television and movies.
For 3D animations, objects (models) are built into the computer monitor (modeling) and 3D figures are rigged with a virtual skeleton. For 2D figure animations, separate objects (illustrations) and independent transparent layers are used with or without that virtual skeleton. Then the members, eyes, mouth, clothes, etc. Of the figure are moved by the animator into the keyframes. Differences in appearance between keyframes are automatically calculated by the computer in a process known as interpolation or morphing. Finally, the animation is rendered.
For 3D animations, all frames must be rendered after completing the modeling. For 2D vector animations, the rendering process is the key frame illustration process, while the interpolated frames are represented as needed. For prerecorded presentations, rendered frames are transferred to a different format or medium, such as digital video. Frames can also be rendered in real-time when presented to the end-user audience. Low-bandwidth animations transmitted over the Internet (for example, Adobe Flash, X3D) often use software on the end-user's computer to render in real-time as an alternative to streaming or preloaded high- band.