A Hinge axis may be oriented by directing the axis toward a specific surface location on a Parent component. Note that you may choose SURFPT as the orientation option without having a Parent but the U/W settings will have no effect. In that case, you will use the offset values to determine direction. When the Hinge is a child of some component and SURFPT is selected, the U/W location on the parent surface is used to direct the Hinge axis along with any particular offset the user chooses. Note that the Hinge does not have to be *attached* to the Parent in order to use the reference points. This means that a Hinge may reference a surface location without being attached to or even placed near the Parent.