Follow an Actor on a Path trailing by the Actor's offset.
Follow-On can be used to follow an Actor that is itself following on. In this way "Trains" can be built up like a locomotive and a set of box cars. The loco follows a path, the first box car follows-on from the loco, and the others follow-on the Actor in front of each.
Note that Paths, Targets, and Lights do not have an offset to follow.
The Actor to be followed is specified by clicking the Select button in the Follow box of the Movement Timeline dialog. When an Actor has been selected the radio buttons for the Follow options will be enabled.