Makes an existing curve a periodic NURBS curve. A periodic NURBS curve is a closed curve with a simple knot at the seam. If a joined curve is made periodic, it becomes a single-span curve and can no longer be exploded.
Rhino.MakeCurvePeriodic (strObject [, blnDelete [, blnSmooth]])
| strObject | Required. String. The object's identifier. | 
| blnDelete | Optional. Boolean. Delete input curve. If omitted, the input curve will not be deleted (False). | 
| blnSmooth | Optional. Boolean. Controls kink removal. If true, smooths any kinks in the curve and moves control points to make a smooth curve. If false, control point locations are not changed or changed minimally (only one point may move) and only the knot vector is altered. The default is False. | 
| String | If blnDelete is False, the identifier of the new object if successful. | 
| String | If blnDelete is True, the identifier of the modified object if successful. | 
| Null | If not successful, or on error. | 
Const rhObjectCurve = 4
Dim strObject
strObject = Rhino.GetObject("Select a curve", rhObjectCurve)
If Not Rhino.IsCurvePeriodic(strObject) Then
Rhino.MakeCurvePeriodic strObject
End If