code: def delaunay_3d(dataset, alpha=0, tol=0.001, offset=2.5):
          
          alg = vtk.vtkDelaunay3D()
          alg.SetInputData(dataset)
          alg.SetAlpha(alpha)
          alg.SetTolerance(tol)
          alg.SetOffset(offset)
          alg.Update()
          return _get_output(alg)
docs: Constructs a 3D Delaunay triangulation of the mesh.
          This helps smooth out a rugged mesh.
  
          Parameters
          ----------
          alpha : float, optional
              Distance value to control output of this filter. For a non-zero
              alpha value, only verts, edges, faces, or tetra contained within
              the circumsphere (of radius alpha) will be output. Otherwise, only
              tetrahedra will be output.
  
          tol : float, optional
              tolerance to control discarding of closely spaced points.
              This tolerance is specified as a fraction of the diagonal length
              of the bounding box of the points.
  
          offset : float, optional
              multiplier to control the size of the initial, bounding Delaunay
              triangulation.