Barriers are essentially walls that you can add to a room. Barriers can not be passed through with your camera. This makes them great for creating board games, mazes, and houses with separate rooms.
You can extend the length and width of barriers to fit your specific build. You can also change the color and opacity of the barriers to fit the aesthetic of your room (which means you can have invisible barriers for traps!)
(The walls, floors, ceiling, and roof of this house are made out of barriers and can't be passed through)