Averages all keyframes to create smooth movement . Smooth works best when filtering cubic (auto) or resampled curves.
When you select the Smooth filter in the Filters window, you can set the following parameters:
Sample Count
Lets you set the number of samples that are taken on the curve. The default value is 8.
Width
Lets you set the smoothing window width. The default value is 4. Greater values strengthen smoothing, while lesser values decrease smoothing.
Use Quaternions
Converts rotation curves to quaternions before smoothing. Quaternions are converted back to Euler curves after smoothing.
Smooth A. Original curve B. Smooth applied with Use Quaternions