Min distance between a curveNode and another node?

Hello,
I wanted to find the minimum distance between the curve (defined by a list of point in a vtkmrmlCurveNode) and other nodes which are vtkPolyData by using (I think) a vtkPolyDataDistanceFIlter. I started by created this curve node with the method where pointPositions is my list of points:
curveNode = slicer.mrmlScene.AddNewNodeByClass(“vtkMRMLMarkupsCurveNode”)
slicer.util.updateMarkupsControlPointsFromArray(curveNode, pointPositions)

After that I’ve tried to use the vtkPolyDataDistanceFIlter:

    distanceFilter = vtk.vtkDistancePolyDataFilter()
    curveA = curve.GetCurveWorld()
    mapper = vtk.vtkDataSetMapper()
    mapper.SetInputData(curveA)
    distanceFilter.SetInputConnection(0,obst.GetPolyDataConnection())
    distanceFilter.SetInputConnection(1,mapper.GetOutputPort())
    distanceFilter.Update()
    d = distanceFilter.GetOutput().GetPointData().GetScalars().GetRange()[0] 

My problem is that there is an error for the SetInputConnection of the curve part If I don’t use a mapper, and with the mapper I get a ‘nontype’ for the last line above. I’ve tried by using curve and it is not working.
Is there a method to resolve the problem please?

curve.GetCurveWorld() returns a vtkPolyData object that you can set as input of a VTK filter using SetInputData() method.

Since you don’t need to implement any rendering, you can remove the lines that refer to the mapper.