Apple Motion 4 - Manual (Page 1297)

When a track is lost during an analysis, Motion automatically jumps back to the frame at
which the track failed. The “bad” track point is identified by an “x” in the Canvas.
You can use the bad track point, or use any point prior to the failed track frame, to move
the tracker and select a new reference feature. In the Canvas, the track point at the current
playhead position is emphasized.
The track point at the
current playhead is
highlighted.
2 Select the Offset Track checkbox in the HUD or Behaviors tab of the Inspector.
Offset Track checkbox
1297 Chapter 19 Motion Tracking