Drawing a region

With no region drawn, the whole frame is watched.

• Rectangle — drag a box. Fastest, and enough for most scenes.
• Polygon — click each corner in turn, then press Close shape. Use this for a hallway, a stairwell, or anything an upright box would fit badly.
• Freehand — drag to trace an outline. On release it's simplified to a handful of draggable corners, so you can still adjust it afterwards.

Select a shape by clicking it, then drag its corner handles to adjust. Undo and redo work throughout.