code: def addCurvatureScalars(self, method=0, lut=None):
          
          curve = vtk.vtkCurvatures()
          curve.SetInputData(self.poly)
          curve.SetCurvatureType(method)
          curve.Update()
          self.poly = curve.GetOutput()
  
          scls = self.poly.GetPointData().GetScalars().GetRange()
          print("curvature(): scalar range is", scls)
  
          self.mapper.SetInputData(self.poly)
          if lut:
              self.mapper.SetLookupTable(lut)
              self.mapper.SetUseLookupTableScalarRange(1)
          self.mapper.Update()
          self.Modified()
          self.mapper.ScalarVisibilityOn()
          return self
docs: Build an ``Actor`` that contains the color coded surface
          curvature calculated in three different ways.
  
          :param int method: 0-gaussian, 1-mean, 2-max, 3-min curvature.
          :param float lut: optional look up table.
  
          :Example:
              .. code-block:: python
              
                  from vtkplotter import *
                  t = Torus().addCurvatureScalars()
                  show(t)
  
              |curvature|