Chromanator Tutorials: Animation
Introduction to keyframing and tweening
Animating in all CSB-Digital products is a very easy affair, once you have learnt the basics. The two areas that newcomers have most trouble with are the terms tweening and keyframes . Once you have worked out what these terms mean, animating becomes a lot clearer.
Everybody knows that a movie is made up of several frames, with each frame being a still image. When these frames are played back one after another in sequence, it creates the illusion of movement. In most video programs, frames are represented on the timeline, a horizontal bar at the bottom of the screen that displays the length of your movie, broken down into its individual frames. The playhead can be moved along the timeline and the current frame will be displayed on the canvas.
Keyframes are special frames that contain specific information about the movie at that point in time. In the case of animation, a keyframe might contain information on the position of one corner of the quad, or it might contain information about how much the object is rotated.
Whenever an attribute is altered using either the canvas or the toolbox, keyframes are automatically added to the timeline in the appropriate place containing the relevant information.
Animation would be a very laborious process if keyframes had to be set for every single frame. Traditional cel and stop-motion animation required that every frame be photographed by the camera, but computers have the ability to perform 'in-betweening' – usually called 'tweening'.
This involves taking the information held in two separate keyframes, and automatically working out the values for all the frames in-between them. Of course, sometimes this method does not prove to be as accurate as required, in which case more keyframes will have to be added.
The power of tweening lies in its flexibility and the way it works entirely in the background. You can add just two keyframes, 500 frames apart, or you can add keyframes to every single frame. It is entirely up to you and the needs of the project. Once understood, tweening can drastically shorten the time spent working on a project.