code: def volume(self, value=None):
          
          mass = vtk.vtkMassProperties()
          mass.SetGlobalWarningDisplay(0)
          mass.SetInputData(self.polydata())
          mass.Update()
          v = mass.GetVolume()
          if value is not None:
              if not v:
                  colors.printc("~bomb Volume is zero: cannot rescale.", c=1, end="")
                  colors.printc(" Consider adding actor.triangle()", c=1)
                  return self
              self.scale(value / v)
              return self
          else:
              return v
docs: Get/set the volume occupied by actor.