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.
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.)
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.
Note: Right-click (Windows) or Command-click (Mac OS) a keyframe
to open its context menu.
- 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.
- In the Timeline panel, select the
layer for which to modify the motion path.
- 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.
- In the Composition panel or Layer panel, use the Selection
tool to drag a keyframe or its handles.
Note: The current-time indicator does not need to be located
on a keyframe before you drag it.

Drag a keyframe in the Composition panel to move one Position
keyframe.
You can move multiple keyframes at
one time by selecting them in the Timeline panel before you drag
them in the Composition panel or Layer panel. To move the entire
motion path, select all keyframes by clicking the property name
in the Timeline panel before dragging a keyframe in the Composition
panel.

Dragging all keyframes on a motion path by one keyframe
-
Display the motion
path that you want to modify in the Composition panel or Layer panel.
- Select the Pen tool
or
Add Vertex tool
from
the Tools panel.
- In the Composition panel, move the Pen tool over the
motion path where you want to add the new keyframe and click to
add the keyframe.
A new keyframe appears at the frame you clicked, on the
motion path and in the Timeline panel. To move the keyframe, use
the Selection tool.
Note: Though the results are different, the tools
for manipulating motion-path curves with the Pen tool work in much
the same way as those used to create and modify other Bezier paths,
such as mask and shape paths.