User Guide

CHAPTER 5
176
Animating Layers
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.
For a more fluid animation after you create a motion path using Motion Sketch, use the
Smoother to eliminate unnecessary keyframes. See “Smoothing motion and velocity” on
page 177 for information on using the Smoother.
To sketch a motion path:
1 In the Composition or Timeline window, select the layer for which you want to sketch
a motion path.
2 In the Timeline window, set the work-area markers to the area in which you want to
sketch motion.
3 Choose Window > Motion Sketch.
4 Select one of the following Motion Sketch options:
• Show Wireframe displays a wireframe view of the layer as you sketch the motion path.
In addition, you can see any rotation or scaling that you have applied to the layer.
• Keep Background displays the contents of the Composition window while you sketch.
This is useful if you want to sketch motion relative to other images in your composition.
After Effects does not show the animation of other layers, however; while you sketch, After
Effects displays only the first frame at the time you start sketching. If you do not select this
option, After Effects displays the motion path as a series of white dots on a black
background.
5 If the composition contains audio, choose Window > Time Controls and click the
Audio button to play all audio in the composition as you sketch.
6 For Capture Speed At, set the capture speed of the motion by specifying a percentage
for how fast the motion plays back in relation to how fast you draw the path. Set the
playback speed in one of the following ways:
• To set the playback speed to the exact speed at which you sketch, set the capture speed
to 100%.
• To set the playback speed faster than the sketching speed, set the capture speed greater
than 100%.
• To set the playback speed slower than the sketching speed, set the capture speed less
than 100%.
UG.book Page 176 Wednesday, February 21, 2001 12:05 PM