How After Effects tracks motion (Pro only)

After Effects tracks motion by matching pixels (actually subpixels) from a selected area in a frame to pixels in each succeeding frame. You specify the area to track by using the track point. The track point contains a feature region, a search region, and an attach point. After Effects displays the track point during tracking in the Layer window.


Layer Window with Track Point A. Search Region B. Feature Region C. Attach Point

Feature region

The feature region defines the area in the moving footage to be tracked. It should surround a distinct feature. After Effects must be able to clearly identify the feature throughout the footage, despite changes in light, background, and angle.

Search region

The search region limits the area that After Effects must search to locate the feature. The feature needs to stand out only within the boundary of the search region, not within the entire frame. Confining the search to a small region saves search time and makes the search process easier.

Attach point

The attach point designates the place of attachment for the target footage--the layer, image, or effect that you want to synchronize with the motion footage.