An offset origin track has a fixed assigned world position that, for a given coordinate system, uniquely determines its image position at each step in a video clip. When an offset origin is dragged in the main video view, the origin of the coordinate system moves with it in order to maintain the offset origin's assigned world position. This makes it useful for remotely setting the position of the origin, particularly when the origin is outside the video image.

1. Marking an Offset Origin

After creating an offset origin, click on a feature in the video image that has a known world position. Marking a single frame is all that's required. The offset origin is initially assigned the current world position of the clicked image feature. The x- and y-components of the world position are displayed on the toolbar when the offset origin is selected.

2. Changing the World Position

Select the offset origin and enter the desired values in the x and y fields on the toolbar to change its world position.

Note: changing the world position of an offset origin moves the coordinate system origin so that it's own image position remains unchanged.

3. Changing the Image Position

Select and drag or nudge the offset origin to a desired location in the main video view.

Note: changing the image position of an offset origin moves the coordinate system origin so that it's own world position remains unchanged.

4. Locking the Offset Origin

Locking the offset origin prevents it from making any changes to the origin. Lock the offset origin by turning on the Locked property in its track menu.