Track the position of a filter or object in Motion

You can use the Track behavior to analyze motion in a video clip, then apply that tracking data to the center parameter of a filter. For example, you can track the center of a Light Rays filter to a moving light in a clip.

You can also use the Track behavior to apply existing tracking data (recorded by another tracking behavior) to the position or anchor point parameter of an object, such as a shape or text.

Note: This behavior applies only to filters with Center parameters, such as Scrape, Ring Warp, Light Rays, Slit Tunnel, and so on.

Track the position parameter of a filter to a source object in a clip

In Motion, apply a filter (that includes a Center parameter) to a layer in your project.
Move the playhead to the frame where you want to start the track analysis.
In the canvas, drag the center point of the filter to the region of the layer (a video clip or animated shape) you want to track.
If the filter’s onscreen controls aren’t visible in the canvas, make sure the filter is selected in the Layers list.
Do one of the following:
- In the canvas, Control-click the Center onscreen control, then choose Track.
- In the Filters Inspector, Control-click the Center parameter, then choose Add Parameter Behavior > Track from the shortcut menu.
In the canvas, the filter’s onscreen control is replaced with an object tracker.
Tip: If the reference pattern you want to track is offset from the center of the filter, use the Offset Track checkbox. For more information on using the Offset Track parameter, see Track obscured or off-frame points in Motion.
Do any of the following:
- Track an area of the clip: In the canvas, drag the object tracker to the reference pattern you want to track. (To better see the reference pattern, turn off the filter in the Layers list.)
- Track a suggested subject in the clip: Press and hold the Option key, then drag over elements in the canvas. As you drag, bounding boxes appear over elements and elliptical shapes appear over faces, suggesting regions of interest that may be trackable.
  When you release the mouse button over the element you want to track, the object tracker conforms to the subject.
- Track a face in the clip: In the Behaviors Inspector, click the Detect pop-up menu, then choose Faces. Onscreen controls appear around any faces detected in the frame. When you click the onscreen control for the face you want to track, the object tracker conforms to the subject.
  Note: A suggested region of interest doesn’t indicate that it can be successfully tracked; the region of interest is recognized using machine learning algorithms that identify common objects.
If necessary, change the shape or size of the object tracker.
In the Behaviors Inspector, click the Analysis Method pop-up menu, then choose one of the following options:
- Automatic: Automatically chooses the most suitable analysis method. Because the best method is highly dependent on the properties of a clip and each use case, you may need to experiment with different analysis methods to achieve the best result.
- Combined: Uses a combination of the Machine Learning and Point Cloud analysis methods (described below) to track position, scale, and rotation.
- Machine Learning: Uses a machine learning model trained on a dataset to identify people, animals, and many other common objects, allowing the tracker to follow the subject in a specified region of video. Choose this option when absolute tracking precision isn’t required, such as when attaching titles or graphics to objects or people. This method can overcome moderate occlusion—when an object (such as a tree or car) briefly obscures the subject being tracked.
- Point Cloud: Tracks a specific reference pattern and identifies how the pattern transforms from one frame to the next. Choose this option when you need more precise tracking of specific pixels. This method tracks position, scale, and rotation, and excels at tracking regions that are rigid and somewhat flat (from the camera’s point of view).
  Note: You can use different tracking analysis methods over different ranges of frames (in the same clip).
In the Behaviors Inspector, do one of the following:
- Analyze the entire clip: Click Analyze. The clip is analyzed forward from the playhead position to the end of the clip (or to the frame where the reference pattern can no longer be tracked), and then backward from the playhead position to the start of the clip.
- Analyze the portion of the clip before the playhead position: Click the left arrows next to the Analyze button.
- Analyze the portion of the clip after the playhead position: Click the right arrows next to the Analyze button.
The tracking analysis progress window displays the analysis method used for the track.
Tip: If you’re using the Machine Learning analysis method and observe jitter during the analysis (the onscreen object tracker bouncing or jumping from one size to another), try switching to the Point Cloud analysis method. Its tracker is much less susceptible to quick changes.
To stop the tracking analysis, click the Stop button in the progress window or press Esc.
Tracking keyframes appear in the Keyframe Editor. If the Keyframe Editor is not visible, click the Show/Hide Keyframe Editor button in the lower-left corner of the Motion window.
In addition to the tracking keyframes, a confidence curve is displayed in the Keyframe Editor. This curve provides a visual indication of the tracker’s accuracy relative to its parameter settings in the Inspector. The confidence curve is for reference only and is not used for editing purposes.

The filter’s center is tracked to the clip. You can make changes to the filter parameters after the analysis is performed. The Track parameter behavior can also use existing tracking data recorded by another tracking behavior.

Track the position parameter of a filter to points or patterns in a source clip

In Motion, follow steps 1–4 in the above task.
In the Behaviors Inspector, click the Mode pop-up menu, then choose Point.
The onscreen tracker changes to a point tracker.
In the canvas, drag the point tracker to the reference point you want to use.
In the Behaviors Inspector (or HUD), do one of the following:
- Analyze the clip forward from the position of the playhead: Click Analyze.
- Analyze the portion of the clip before the playhead position: Click the left arrows next to the Analyze button.
- Analyze the portion of the clip after the playhead position: Click the right arrows next to the Analyze button.
When the tracking analysis begins, a progress window opens and points appear on a motion path in the canvas.
To stop a track analysis, click the Stop button in the progress window or press Esc.
The points in the canvas correspond to the tracking keyframes that appear in the Keyframe Editor. If the Keyframe Editor is not visible, click the Show/Hide Keyframe Editor button in the lower-left corner of the Motion window.
A confidence curve is also displayed in the Keyframe Editor. This curve provides a visual indication of the tracker’s accuracy relative to its parameter settings in the Inspector. The confidence curve is for reference only and is not used for editing purposes.

Apply tracking data to the position or anchor point of an object

Using the Track behavior, you can apply existing tracking data to the Position or Anchor Point parameters of an object.

Important: Before you can apply tracking data to an object’s parameters, your project must contain a tracking behavior (such as Analyze Motion) that has analyzed a clip.

In the Layers list in Motion, select the object that you want to apply the tracking data to.
In the Properties Inspector, do either of the following:
- Control-click the Position (or Anchor Point) parameter, then choose Add Parameter Behavior > Track.
- Click the Position (or Anchor Point) parameter’s Animation menu (the down arrow that appears when you move the pointer over the right side of a parameter row), then choose Add Parameter Behavior > Track.
In the Behaviors Inspector, click the Action pop-up menu (with the gear icon), then choose a tracking behavior.
Tracking data from the selected behavior in the project is applied to the Position (or Anchor Point) parameter.
To quickly reassign the tracking data from the Position parameter to the Anchor Point parameter (or vice-versa), click “To” in the Apply To row (in the Behaviors Inspector), choose Properties > Transform, then choose Position or Anchor Point.

For a full description of adjustable controls in the Track behavior, see Track controls in Motion.

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Motion User Guide

Track the position of a filter or object in Motion

Track the position parameter of a filter to a source object in a clip

Track the position parameter of a filter to points or patterns in a source clip

Apply tracking data to the position or anchor point of an object