Lasso Tool allows to select objects or nodes in the work area with polygon. This tools is useful when there is a large number of objects in the work area, they are close one to another and it is not possible to use simple rectangular selection.
Click anywhere in the work area to place the first point. Then repeat clicking to create the polygon. It is not necessary to close the polygon. Connection from last point to the first point is created automatically. You can adjust the shape of polygon by clicking on existing point and dragging it to a new position. Arrow indicates orientation of the polygon and it is displayed on line segment after focused (highlighted) point.
It is possible to insert or delete lasso points with with use of INSERT and DEL keys on the keyboard. Point is inserted on place where arrow is displayed. Deleting point erases the highlighted point. New points are also created by clicking on empty area (i.e. not on existing point). New point is created after the highlighted point, so that segment with arrow is split in two parts.
If your device has no keyboard then insert or delete points with + and - buttons from the menu panel.
All changes to polygon are stored to memory. Therefore, it is possible to use Undo/Redo buttons or CTRL+Z/CTRL+Y shortcuts.
There are several options how to apply polygonal selection: