The first, second and third axis of the local coordinate system of the polygon are defined automatically. The first axis is according to the global coordinate system and lies with the second axis in the plane of the polygon. The third axis is perpendicular to the plane of the polygon.
Manual
The first axis of the local coordinate system of the polygon is defined manually, the third axis is perpendicular to the plane of the polygon and the second axis is determined automatically from the first- and third axis.