code: def smoothWSinc(self, niter=15, passBand=0.1, edgeAngle=15, featureAngle=60):
          
          poly = self.poly
          cl = vtk.vtkCleanPolyData()
          cl.SetInputData(poly)
          cl.Update()
          smoothFilter = vtk.vtkWindowedSincPolyDataFilter()
          smoothFilter.SetInputData(cl.GetOutput())
          smoothFilter.SetNumberOfIterations(niter)
          smoothFilter.SetEdgeAngle(edgeAngle)
          smoothFilter.SetFeatureAngle(featureAngle)
          smoothFilter.SetPassBand(passBand)
          smoothFilter.NormalizeCoordinatesOn()
          smoothFilter.NonManifoldSmoothingOn()
          smoothFilter.FeatureEdgeSmoothingOn()
          smoothFilter.BoundarySmoothingOn()
          smoothFilter.Update()
          return self.updateMesh(smoothFilter.GetOutput())
docs: Adjust mesh point positions using the `Windowed Sinc` function interpolation kernel.
  
          :param int niter: number of iterations.
          :param float passBand: set the passband value for the windowed sinc filter.
          :param float edgeAngle: edge angle to control smoothing along edges (either interior or boundary).
          :param float featureAngle: specifies the feature angle for sharp edge identification.
  
          .. hint:: |mesh_smoothers| |mesh_smoothers.py|_