Correcting a drifting feature region (Pro only)

As an image moves in a shot, the lighting, surrounding objects, and angle of the object can all change, making the once distinct feature no longer identifiable at the subpixel level. It takes time to develop an eye for choosing a trackable feature. Even with careful planning and practice, you will often find that the feature region drifts away from the desired feature. Re-adjusting the feature and search regions, changing the tracking options, and trying again is a standard part of digital tracking. When drifting occurs, you may need to perform any combination of the following adjustments:

• Resize the feature and search regions and track again.
• Track the shot in sections, redefining the feature region in places where the feature changes and the region drifts.
• Track a different area with movement that closely matches that of the feature. If you are applying an effect or adding something to a specific point, you usually want to track close to the original feature. For example, you may want to add a glow effect to the end of a sword, but the lighting in the shot creates so much glare on the tip of the sword that tracking it is impossible. Tracking the opposite end of the sword would generate a much different motion path than tracking the tip. (This is where planning ahead before you shoot can really pay off.)
• Add a high-contrast object to the scene either attached to the object or in an area that matches the movement of the feature before you shoot.
• Adjust the tracking options to change the comparison method or precision of the frame-to-frame tracking.

Related Subtopics:

Understanding the tracker plug-in options (Pro only)
Drift correction methods (Pro only)