about walkable areas

1 how to delete a walkable area
2 how to draw a second series of way points
3how to actived or deactived walable areas(when the character open the door)

You need to create multiple version of way systems for each room if something should change in said room. If a door is open or closed or maybe something in the room has collapsed or an hole has been blown through a wall or the floor.

1. create your way systems.
2. change to required way system as needed.

Quick note: it's probably better to duplicate or copy / paste your initial way system & edit as desired.