Reference

The Reference is the vertex on a rectangular landing from which the position values are calculated in the graphical view. In the figure below the Reference is at vertex 6.

To change the Reference select the vertex from the drop-down list. A bounding box shows the new position of the landing. If it does not put the landing in the correct position select a different vertex from the drop-down list.

For circular and complex landings the reference is always the centre.