Oh sorry, I confused that tutorial with one on my Moving With Motion training DVD. The Look-ahead frames feature is a way to give Motion a hint. If you have a fast-moving object or a object moving in a straight line…with nothing in the way. It lets you look and then track frames ahead of or behind the playhead (behind if the reverse checkbox is checked). I hope this helps. Here is instructions on how to use it:
To define look-ahead frames
1-Apply an Analyze Motion behavior to a clip.
2-In the Canvas, position the tracker on the desired reference pattern.
3-In the Behaviors tab of the Inspector, use the Look Ahead Frames slider or value slider to specify how many frames you want the tracker to look ahead.
Note: The maximum default for the Look Ahead Frames slider is 10 frames. However, you can enter a larger frame amount using the adjacent value slider.
3-While holding down the Command key, click the tracker in the Canvas, then drag in the direction the reference pattern is moving in the clip.
As you Command-drag the track point, an inset displays a magnified view of the frame specified in the Look Ahead Frames parameter.
4-When the look-ahead tracker is positioned on the reference pattern, release the mouse button.
When you click the Analyze button, the new reference point is used as the tracking pattern.
Stephen Smith
Utah Video Productions
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