Boundary - is a special object toward which people move during evacuation: exits, the lower and upper ends of stairways or ramps, waypoints.
Boundaries formed by the edges of stairways and ramps connect two areas. When crossing such a boundary, the type of path along which a person moves changes. Upon reaching the boundary of the stairway, a person selects the next boundary toward which they move.
Boundaries formed by exits represent the endpoint of a person’s movement. When reaching such a boundary, the person is considered evacuated and is removed from the simulation. These boundaries can only be located on horizontal areas.
Boundaries formed by exits are displayed as green edges on the navigation graph:
Boundaries formed by waypoints do not connect areas like stairways; similar to exits, they can only be located on horizontal areas. However, these boundaries are intermediate—upon reaching them, a person must select the next boundary.
For each boundary that a person moves toward along a horizontal path, a navigation graph is constructed within the area. The navigation graph contains information about the distance and shortest direction to the boundary from points within the area.
All boundaries collectively form a unified path graph. The path graph contains information about the distance from each boundary to an exit.