Construct and undo a chain of walls automatically
Using this function, you can construct a chain of walls (a room) when you have fixed three or more wall points, and also undo it again.
When you undo a room, it is always the last wall that is removed.
Construct a chain of walls manually
When you have fixed three or more wall points, you can also construct a chain of walls manually by fixing a new wall point on the first one.