Computer animation

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, though 2D computer graphics are still widely used for stylistic, low bandwidth, and faster real-time rendering needs. Sometimes the target of the animation is the computer itself, but sometimes the target is another medium, such as film. It is also referred to as CGI (Computer-generated imagery or computer-generated imaging), especially when used in films.

Virtual entities may contain and be controlled by assorted attributes, such as transform values (location, orientation, and scale) stored in an object's transformation matrix. Animation is the change of an attribute over time. Multiple methods of achieving animation exist; the rudimentary form is based on the creation and editing of keyframes, each storing a value at a given time, per attribute to be animated. The 2D/3D graphics software will interpolate between keyframes, creating an editable curve of a value mapped over time, resulting in animation. Other methods of animation include procedural and expression-based techniques: the former consolidates related elements of animated entities into sets of attributes, useful for creating particle effects and crowd simulations; the latter allows an evaluated result returned from a user-defined logical expression, coupled with mathematics, to automate animation in a predictable way (convenient for controlling bone behavior beyond what a hierarchy offers in skeletal system set up).

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 shifted slightly. This technique is identical to the illusion of movement in television and motion pictures.

Notes:

Raster Graphics - Компьютерное растровое изображение представляется в виде прямоугольной матрицы, каждая ячейка которой задана цветной точкой — вместе они фор­мируют целостную картинку. Пиксели подобны зернам фотографии и при значительном увеличении становятся заметными. Растровые изображения используются чаще векторных, так как они более просты в получении и допе­чатной подготовке.

CGI (Computer-generated imagery or computer-generated imaging) - стандарт интерфейса, используемого для связи внешней программы с веб-сервером. Программу, которая работает по такому интерфейсу совместно с веб-сервером, принято называть шлюзом, хотя многие предпочитают на­звания «скрипт» (сценарий) или «CGI-программа».

CGI также может означать «Computer‐ generated imagery» — компьютерные спецэффекты.