@classmethod
def HomogeneousHapke(cls, albedo, assymetry, amplitude, width):
    """Parameterisation for a surface BRDF based on the Hapke model.

        The parameters are:

        - albedo
        - assymetry parameter for the phase function
        - amplitude of hot spot
        - width of the hot spot

         """
    return (
        '0 Homogeneous surface\n1 (directional effects)\n1 (Hapke model)\n%f %f %f %f\n'
         % (albedo, assymetry, amplitude, width))
