Tracking the Position for an Effect

In effect tracking, you apply the stored motion to the position for an effect. Only effects that require you to set a position for the effect can be tracked. These effects (filters) include Lens Flare (Flare Center and Axis), Circular Wipe (Center), and Crumple (Origin). Usually, the point can be picked using the Set Position button or the X and Y fields.

In the following example, a lens flare is tracked to the headlight of the mini-van.

Example: To track the center of a lens flare:

1. Play the source clip several times to watch the feature you want to track and evaluate whether or not it is usable as a reference feature. See Finding a Good Reference Feature.
2. Determine a good reference frame and position the source clip at that frame.
3. In the Workspace panel, select the source layer (the Van).
4. Choose Operators | Stylize | Lens Flare.
5. In the Lens Flare Controls, adjust the lens flare settings.
6. Click the Set Position button for Flare Center.

Crosshairs appear over the center of the lens flare in the viewport.

7. Position the crosshairs (the lens flare follows) over the feature you want to track (for example, the headlight of the van).



Note: For most effects, you can also scrub the Set Position button to set the position.

8. On the Tracker panel, click Position.

A tracker and reference box appear in the viewport.



9. Position the reference box over a feature you can track.



10. Adjust the settings on the Tracker panel.
11. Enable Hide Objects to hide the lens flare so that it does not obscure the reference feature during tracking.
12. On the Tracker panel, click the Analyze Forward button to start the analysis.

The center point of the effect is repositioned at each frame, corresponding to the reference feature.

13. Save the Tracker data if necessary.
14. Click the Off button in the Tracker panel when tracking is complete.

When you play the clip, the effect follows the motion of the reference feature.