Apple Shake 4 - Manual (Page 307)

Chapter 10 Parameter Animation and the Curve Editor 307
Using Keyframe Move Modes
In the Curve Editor, there are four keyframe move modes—Bound, Interleave, Push, and
Replace—that are activated by the four states of the Keyframe Move Mode button.
These modes control the behavior of the keyframes when the keyframes are moved left
or right past non-active keyframes. To change modes, click the Keyframe Move Mode
button in the bottom-left corner of the Curve Editor.
Bound
When the Bound mode is set, the movement of a selected range of keyframes (whether
contiguously or noncontiguously selected) is clamped by the adjacent keyframes. In
the following example, keyframes A, B, and C are selected (highlighted in green) and
moved left in the Curve Editor.
When moved, the selected keyframes cannot move beyond the adjacent keyframe in
the curve, so keyframe A stops at the frame occupied by keyframe 2, and the distance
between A and B shrinks. If you continue to drag left, keyframes A, B, and C are placed
on the same frame.
Interleave