Animation techniques

These techniques simulate continuous motion by rapidly displaying images. The viewer is given the impression that he is watching a continuous motion. To achieve this impression the graphical hardware needs image display rates of at least 25 images per second, since otherwise motion will look shaky. As most graphical hardware can not reach that display rate for moderate sized images (i.e. 256x256 pixels), one uses video hardware. One either sends every image to a framebuffer to write one videoframe at a time to videotape or one stores the images on a fast accessible device, CMY a laserdisk, and, after all images have been stored, displays them on a television screen from where they can be put on a videotape. There are two kinds of animation which we will describe below.

Flipbook animation

This is a well known technique. The generated images are displayed one after the other. Its name is attached to the thumbing or flipping through a series of images.

Keyframe animation

For this technique one only has to generate so-called keyframes. Keyframes mark changes in the characteristics of the motion, for example the sudden change in the direction of motion of an electron due to a collision with an ion. Interpolation techniques are used to generate a set of images between two keyframes. The larger the interpolated set of images the smoother the conversion from one keyframe to the other will appear to the viewer.