Tracking motion to animate effects (Pro only)

You can animate effects applied to the motion source so that they follow a specific feature precisely throughout a shot. After Effects repositions the effect point using the position data it gathered when tracking. For example, you can track the sun as it moves across the sky to animate a lens flare. When applying tracking data to an effect point, the motion target must be an effect control point on the same layer as the motion source.

To animate effects:

1. In the Timeline, select the effect point control you want to animate.

Note: The selected effect must be applied to the motion source layer, and the layer must include motion or changing frames, such as video source footage.

2. Choose Animation > Track Effect Point Control. After Effects then performs the following actions:
• Displays the Tracker Controls palette with the current layer (the layer containing the effect) listed for Motion Source and the effect point control you selected in step 1 for Motion Target.
• Creates a new track and displays its name for Current Track in the Tracker Controls palette.
• Displays Transform for Track Type.
• Adds the new track to the Motion Trackers section of the motion source layer in the Timeline.
• Creates a track point in the Layer window for the motion source.
3. If you want to track a range of frames, define the work area you want to track in the Layer window for the source footage.
4. In the Layer window for the motion source, move the current-time indicator to the frame from which tracking should begin.
5. Using the selection tool, position and size the feature region so that it surrounds the feature you want to track. (See Moving and resizing the track point (Pro only).)

Note: The search region needs to be only big enough to accommodate the frame-to-frame position change of the feature.

6. In the Tracker Controls palette, click either the Forward Analyze or Backward Analyze button to begin tracking. Watch the tracking to make sure it is accurate. If not, click the button again to stop tracking, and then correct the problem as described in Correcting a drifting feature region (Pro only).
7. When you are satisfied with the position of the feature region(s) throughout the footage, click the Apply button to apply the motion to the effect. After Effects creates keyframes and copies them to the effect point control.