def setPoint(self, i, p):
        """
        Set specific `i-th` point coordinates in mesh.
        Actor transformation is reset to its original mesh position/orientation.

        :param int i: index of vertex point.
        :param list p: new coordinates of mesh point.

        .. warning:: if used in a loop this can slow down the execution by a lot.

        .. seealso:: ``actor.Points()``
        """
        poly = self.polydata(False)
        poly.GetPoints().SetPoint(i, p)
        poly.GetPoints().Modified()
        # reset actor to identity matrix position/rotation:
        self.PokeMatrix(vtk.vtkMatrix4x4())
        return self