5

• Add Keyframe: Adds a keyframe at the current frame. If the playhead is positioned
on a frame where a keyframe has been added, this menu item is unavailable. A
keyframe is automatically added to the last modified parameter of the object
(regardless of the status of the Record button) at the current playhead position.
• Delete Keyframe: Deletes the current keyframe. The Delete Keyframe command is
only available if the playhead is positioned on a frame where a keyframe exists. You
can also Control-click a keyframe and choose Delete from the shortcut menu, or
select the keyframe and press Delete.
• Previous Keyframe: Moves the playhead to the previous keyframe for this parameter.
The Previous Keyframe command is only available if a keyframe exists earlier in the
project. You can also press Option-K to advance to the next keyframe.
• Next Keyframe: Moves the playhead to the next keyframe for this parameter. The
Next Keyframe command is only available if a keyframe exists later in the project.
You can also press Shift-K to advance to the next keyframe.
• Interpolation: Sets the type of curve for the parameter. See the table in Modifying
Curves for examples of interpolation methods.
• Before First Keyframe: Defines the animation before the first keyframe of a parameter.
This is called extrapolation. For examples of extrapolation methods, see Extrapolation.
• After Last Keyframe: Defines the animation after the last keyframe of a parameter.
This is called extrapolation. For examples of extrapolation methods, see Extrapolation.
• Lock/Unlock Parameter: Locks the parameter to prevent changes. When a parameter
is locked, neither keyframes nor curves are adjustable.
• Reduce Keyframes: Applies a thinning algorithm to the selected parameter to reduce
the number of keyframes while attempting to maintain a similar curve shape. For
more information on keyframe thinning, see Keyframe Thinning.
• Curve Snapshot: Reverts keyframe changes made in the selected curve to the most
recent snapshot. This menu item is available only when the Take/Show Curve
Snapshot button is enabled. For more information, see Keyframe Editor Control
Buttons and Curve Snapshots.
Keyframe Editor Control Buttons
The upper-right corner of the Keyframe Editor contains six buttons that provide additional
control over the Keyframe Editor window.
Fit Curves
Vertically
Display
Waveform
Clear Curve
List
Fit Curves
Horizontally
Curve
Snapshot
Snapping
115Chapter 2 The Motion Interface