Apple Shake 4 - Manual (Page 309)

Chapter 10 Parameter Animation and the Curve Editor 309
When the Replace mode is set, the selected keyframes replace the adjacent non-
selected keyframe(s). In the following example, keyframes A, B, and C have slipped past
the position of keyframes 1 and 2, removing them from the curve.
Applying Operations to Curves
To apply operations such as Smooth and Jitter to curves or keyframes, use the Apply
Operation button, located in the lower-left corner of the Curve Editor.
To apply an operation to a curve or to keyframes:
1 Select the curve from the parameters list, or, if applying the function to keyframes,
select the keyframes in the Curve Editor.
2 In the Curve Editor, click the Apply Operation button.
3 In the Curve Processing window, select your operation.