What do the Letters in the line crossing event mean?

Question

What do the Letters in the line crossing event mean?

Answer

When creating a 'Lines-crossing' event there are the letters 'A' and 'B' on both sides of the line. These letter are to represent the direction the object will pass to trigger the event. Such that A<|>B means when the object will trigger crossing the line going either ways, while A|>B means when the object moves from 'A'  across the line to 'B' it will trigger but not when it goes from 'B' to 'A'. and vice versa for B|>A