def volume(self, value=None):
        """Get/set the volume occupied by actor."""
        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
Get/set the volume occupied by actor.