Public Function AddCenterPlane( _
   ByVal PlacementElement1 As Object, _
   ByVal PlacementElement2 As Object, _
   ByVal TargetElement1 As Object, _
   ByVal TargetElement2 As Object, _
   ByRef PlacementConstrainingPoint1() As Double, _
   ByRef PlacementConstrainingPoint2() As Double, _
   ByRef TargetConstrainingPoint1() As Double, _
   ByRef TargetConstrainingPoint2() As Double _
) As CenterPlaneRelation3d