DIRECTIONAL TRIGGER for Scripters.
This Trigger posts 'Forward' and 'Backward' messages when crossed by a train. These messages can be used by scripters for future assets.
(Note that existing assets will continue to see this Trigger as Non-Directional!)
The 'Forward-Backward' directions are relative to the arrow shape of the Trigger.
ie - A train travelling in the direction of the arrow produces 'ForwardEnter' and 'ForwardLeave' messages.
A train travelling against the arrow produces 'BackwardEnter' and 'BackwardLeave' messages.
Be aware that the Trigger also produces the normal NON-directional 'Enter' and 'Leave' messages so the scripter will need to ignore those messages and listen for the directional ones.