### Summary

This chapter discusses what motion editing is, why it is important, and different methods for motion editing.

### Problem

Sometimes it is necessary to modify a motion, particularly motion capture data, but this can also apply to other forms of animation such as keyframing. A motion may need to be modified in order to fit it to a different character (retargetting), cleanup a bad motion, create an infeasible motion, or just change certain properties of the motion (including emotion or intent).

### Key Ideas

1. Motion capture data is difficult to edit because there is a large amount of data with many keyframes -- many of which are unnecessary requiring more editing than desired.

2. LPF motion data can clean up motion data, but removes the crispness in actions in addition to the noise.

3. Key reduction can be used to approximate the motion by reducing the number of key frames making the data more editable.

4. Motion can be described as a signal, thus allowing signal processing techniques to be applied to it, including filtering and resampling.

5. Motion warping provides a technique for adding special motions or effects and blending them together to create new motions.