PhysicsCollisionHandler + CollisionSegment = ?

I’m trying detect when my character crosses a line and moves from one room to another. My idea is to have a “trip wire” in the form of a CollisionSegment to generate an event.

It’s been my experience that when the built-in physics are being used, it’s best not to have any collision objects intersecting. There’s already an invisible cube in the doorway blocking enemies from leaving the room. My character can walk through it because of his collide bitmask. The trip wire would need to be inside this cube on the floor, therefore intersecting it.

I could (and probably will) try this, but I wanted to get your opinions on this approach. Am I making things more difficult than they need to be?

Am I being clear enough on what I’m trying to do?