Insert Lighting Group Vertex
To add a vertex to a lighting group area boundary, go to
Ribbon:
Pulldown Menu:
You will be prompted to specify a point either inside or outside of the area boundary for which a vertex is to be inserted.
First fence point crossing lighting group boundary:
You will then be prompted to specify a point on the opposite side of the area boundary. The line between the two points should cross the boundary where you want the new point to be inserted.
Second fence point:
A new vertex will be inserted on the boundary. The appearance of the boundary will not change, but you will have two new grips that you can use to drag the boundary into the correct shape.