You
can draw a path for the motion of a selected layer using Motion
Sketch, which records the position of the layer and the speed at
which you draw. As you draw, a Position keyframe is generated at
each frame.
Motion Sketch does not affect keyframes that
you have set for other properties. For example, if you set Rotation
keyframes for an image of a ball, you can use Motion Sketch to generate
Position keyframes, so that the ball appears to roll along the path
you created.
In the Composition or Timeline panel, select the
layer for which you want to sketch a motion path.
In the Timeline panel, set the work-area markers to the
duration in which you want to sketch motion.
Choose Window > Motion Sketch.
Select the appropriate Motion Sketch options:
Show Wireframe
Displays a wireframe view of the layer as you sketch the motion
path.
Show Background
Displays the static contents of the frame at which you started
sketching in the Composition panel while you sketch. This is useful
if you want to sketch motion relative to other images in your composition.
Smoothing
Eliminates unnecessary keyframes from the motion path. This setting
has the same result as using the Tolerance setting with The Smoother. Higher
values produce smoother curves, but too high a value may not preserve the
shape of the curve that you draw.
Note: You can smooth a motion
path after it has been created by using the smooth expression
or The Smoother.
Capture Speed At
The ratio of the speed of the recorded motion to playback speed.
If Capture Speed At is 100%, the motion is played back at the speed
at which it was recorded. If Capture Speed At is greater than 100%,
the motion plays back slower than it was recorded.
Click Start Capture and then drag in the Composition
panel to create the motion path. Release the mouse button to stop
capturing.
Note: After Effects automatically ends capturing when the
capture time reaches the end of the work area (which, by default,
is the composition duration).
Comments are no longer accepted for After Effects CS3. After Effects CS4 is the current version. To
discuss After Effects CS3, please use the Adobe forum.
Comments
Comments are no longer accepted for After Effects CS3. After Effects CS4 is the current version. To discuss After Effects CS3, please use the Adobe forum.