Connect Two Curves

💻 Rhino 5

🔼 Rhino Script

🛠️ Visual Basic

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This Rhino script allows the user to select two curves to be connected, closing them into a single polyline, using either a rough equivalent of blend curve or straight connections… or not, it’s your call, give it a try you’ll see what I mean. It’s a great time saver for closing offset curves.

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Option Explicit
'Script written by <David Mans>
'Script copyrighted by <Neoarchaic Design>
'Script version Monday, September 01, 2008 6:39:25 AM
 
Call Main()
Sub Main()
    Call connectTwoCurves()
End Sub
Function connectTwoCurves()
    connectTwoCurves = Null
    Dim curve(1)
    curve(0) = Rhino.GetObject("Select Curve 1", 4)
    If isNull(curve(0)) Then Exit Function
    curve(1) = Rhino.GetObject("Select Curve 2", 4)
    If isNull(curve(1)) Then Exit Function
    Call Rhino.EnableRedraw(False)
    Dim dir
    Dim ptA(1),ptB(1),dist(1),cap(1)
    ptA(0) = Rhino.CurveStartPoint(curve(0))
    ptA(1) = Rhino.CurveEndPoint(curve(0))
    ptB(0) = Rhino.CurveStartPoint(curve(1))
    ptB(1) = Rhino.CurveEndPoint(curve(1))
    dist(0) = Rhino.Distance(ptA(0), ptB(0))
    dist(1) = Rhino.Distance(ptA(0), ptB(1))
     
    If dist(0) = dist(1) Then
        dir = True
        cap(0) = Rhino.AddLine(ptA(0), ptB(0))
        cap(1) = Rhino.AddLine(ptA(1), ptB(1))
    Else
        If dist(0) < dist(1) Then
            dir = True
            cap(0) = Rhino.AddLine(ptA(0), ptB(0))
            cap(1) = Rhino.AddLine(ptA(1), ptB(1))
        Else
            dir = False
            cap(0) = Rhino.AddLine(ptA(0), ptB(1))
            cap(1) = Rhino.AddLine(ptA(1), ptB(0))
        End If
    End If
    Call Rhino.EnableRedraw(True)
    Dim arrResults,arrInputs,arrValues
    arrInputs = array("Flip", "Yes", "No", "Type", "Smooth", "Straight", "Join", "Yes", "No")
    arrValues = array(True, True, False)
    arrResults = Rhino.GetBoolean("Connection Options", arrInputs, arrValues)
     
    Call Rhino.EnableRedraw(False)
    Dim tan(3),blend, ptC(3)
    If arrResults(1) = False Then
        Call Rhino.DeleteObjects(cap)
        blend = 0.25
        tan(0) = Rhino.VectorScale(Rhino.VectorUnitize(Rhino.VectorReverse(Rhino.CurveTangent(curve(0), Rhino.CurveDomain(curve(0))(0)))), Rhino.Distance(ptA(0), ptA(1)) * blend)
        tan(1) = Rhino.VectorScale(Rhino.VectorUnitize(Rhino.CurveTangent(curve(0), Rhino.CurveDomain(curve(0))(1))), Rhino.Distance(ptA(0), ptA(1)) * blend)
        tan(2) = Rhino.VectorScale(Rhino.VectorUnitize(Rhino.VectorReverse(Rhino.CurveTangent(curve(1), Rhino.CurveDomain(curve(1))(0)))), Rhino.Distance(ptB(0), ptB(1)) * blend)
        tan(3) = Rhino.VectorScale(Rhino.VectorUnitize(Rhino.CurveTangent(curve(1), Rhino.CurveDomain(curve(1))(1))), Rhino.Distance(ptB(0), ptB(1)) * blend)
         
        ptC(0) = Rhino.PointAdd(Rhino.CurveStartPoint(curve(0)), tan(0))
        ptC(1) = Rhino.PointAdd(Rhino.CurveEndPoint(curve(0)), tan(1))
        ptC(2) = Rhino.PointAdd(Rhino.CurveStartPoint(curve(1)), tan(2))
        ptC(3) = Rhino.PointAdd(Rhino.CurveEndPoint(curve(1)), tan(3))
        If arrResults(0) = True Then
            If dir = False Then
                cap(0) = Rhino.AddCurve(array(ptA(0), ptC(0), ptC(3), ptB(1)), 3)
                cap(0) = Rhino.AddCurve(array(ptA(1), ptC(1), ptC(2), ptB(0)), 3)
            Else
                cap(0) = Rhino.AddCurve(array(ptA(0), ptC(0), ptC(2), ptB(0)), 3)
                cap(0) = Rhino.AddCurve(array(ptA(1), ptC(1), ptC(3), ptB(1)), 3)
            End If
        Else
            If dir = False Then
                cap(0) = Rhino.AddCurve(array(ptA(0), ptC(0), ptC(2), ptB(0)), 3)
                cap(0) = Rhino.AddCurve(array(ptA(1), ptC(1), ptC(3), ptB(1)), 3)
            Else
                cap(0) = Rhino.AddCurve(array(ptA(0), ptC(0), ptC(3), ptB(1)), 3)
                cap(0) = Rhino.AddCurve(array(ptA(1), ptC(1), ptC(2), ptB(0)), 3)
            End If
             
        End If
    Else   
        If arrResults(0) = False Then
            Call Rhino.DeleteObjects(cap)
            If dir = False Then
                cap(0) = Rhino.AddLine(ptA(0), ptB(0))
                cap(1) = Rhino.AddLine(ptA(1), ptB(1))
            Else
                cap(0) = Rhino.AddLine(ptA(0), ptB(1))
                cap(1) = Rhino.AddLine(ptA(1), ptB(0))
            End If
        Else
         
        End If
    End If
    If arrResults(2) = False Then
        Call Rhino.JoinCurves(array(curve(0), cap(0), curve(1), cap(1)), True)
    End If
    Call Rhino.EnableRedraw(True)
 
    connectTwoCurves = array()
End Function

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