Nonlinear animation is animation that is not restricted by time. It allows you to work on your animation at a high level of control at any time location in the scene. It gives you high-level control over animation because you can layer and mix sequences in a nonlinear and non-destructive way. As well, you can reuse and fine-tune many sources of data.
Nonlinear animation requires the animation mixer. In it, you create animation or shape sequences, transitions, and mixes. It takes all the underlying animation data and packages it into clips. Each clip is an instance of an animation or shape source that you create. On the frames "covered" by the clip, the data stored in the source drives the animation.
Once you have a library of different types of sources created, you can bring them into the mixer in a completely non-destructive manner (the original data stays untouched), making it easy to experiment.
