Drill 2D selection Mode :
This mode allow to select points using the shape of a 2D polygon

	Create a points could
	Add some polygons facing this cloud and select them
	Run Custom Select , and choose "Drill 2D"
	Result : all point in front of the polygons normals are selected.
	Add a new point cloud behind the polygons
	Run Custom Select, and then check 'Double sided'
	Points behind the polygons are also selected