Creating and modifying motion paths, Work with motion paths – Adobe After Effects CS3 User Manual
Page 202
AFTER EFFECTS CS3
User Guide
197
Creating and modifying motion paths
Work with motion paths
When you animate spatial properties—including Position and Anchor Point properties, as well as effect control
point properties—the motion is shown as a motion path. Position motion paths appear in the Composition panel;
Anchor Point and effect control point motion paths appear in the Layer panel. A motion path appears as a sequence
of dots, where each dot marks the position of the layer at each frame. A box in the path marks the position of a
keyframe.
Note: The density of dots between the boxes in a motion path indicates the layer’s relative speed. Dots close together
indicate a lower speed; dots farther apart indicate a greater speed.
Motion paths are simply an alternative visual, spatial way of viewing and working with spatial properties and their
keyframes, in addition to the ways that you work with properties in the Timeline panel. You can modify a motion
path by changing an existing keyframe or adding a new keyframe. You can modify a motion path’s shape by changing
the spatial interpolation methods for its keyframes.
Note: Right-click (Windows) or Command-click (Mac OS) a keyframe to open its context menu.
Using the Pen tool or Selection tool to edit keyframes for a spatial property in the Composition or Layer panel is
similar to modifying a Bezier path for a mask or for a shape on a shape layer. (See “About paths” on page 313.)
A motion path is less complex and generally easier to modify when you use fewer keyframes to describe the path.
You can use The Smoother to remove extraneous keyframes from a motion path.
Jonas Hummelstrand and Dan Ebberts provide an animation preset and instructions for scaling and rotating a
motion path:
.
See also
“Work with layer properties in the Timeline panel” on page 152
“About animation, keyframes, and expressions” on page 183
“Modify a Bezier mask path or shape path” on page 323
Show motion path controls
•
To show motion path controls in the Composition panel, choose Composition > View Options, and select Effect
Controls, Keyframes, Motion Paths, and Motion Handles. To see a Position motion path in the Composition
panel, the Position property must be selected.
•
To show motion path controls in the Layer panel, choose the property or effect from the View menu at the bottom
of the Layer panel.
•
To specify how many keyframes to show for a motion path, choose Edit > Preferences > Display (Windows) or
After Effects > Preferences > Display (Mac OS), and select an option in the Motion Path section.
Move motion path keyframes
1
In the Timeline panel, select the layer for which to modify the motion path.
2
If you cannot see the keyframe you want to modify in the Composition panel or Layer panel, move the current-
time indicator to the keyframe.
3
In the Composition panel or Layer panel, use the Selection tool to drag a keyframe or its handles.