The mask editor was not written for handling arbitrary mask. It was written to create simple mask.
I would recommend to first create a rough mask in the overview and then refine the mask in higher zoom level (add more points, move points, remove points).
The mask editor was not written for handling arbitrary mask. It was written to create simple mask.
I would recommend to first create a rough mask in the overview and then refine the mask in higher zoom level (add more points, move points, remove points).