def add_aux_attachment(self, bits=8):
        """ Adds a new aux attachment with the given amount of bits. The amount
        of bits passed overrides all previous bits set, since all aux textures
        have to have the same amount of bits. """
        self._aux_bits = bits
        self._aux_count += 1
 Adds a new aux attachment with the given amount of bits. The amount
        of bits passed overrides all previous bits set, since all aux textures
        have to have the same amount of bits. 
metadrive/render_pipeline/rpcore/render_target.py