def _init_common_stages(self):
        """ Inits the commonly used stages, which don't belong to any plugin,
        but yet are necessary and widely used. """
        add_stage = self.stage_mgr.add_stage
        self._ambient_stage = AmbientStage(self)
        add_stage(self._ambient_stage)
        self._gbuffer_stage = GBufferStage(self)
        add_stage(self._gbuffer_stage)
        self._final_stage = FinalStage(self)
        add_stage(self._final_stage)
        self._downscale_stage = DownscaleZStage(self)
        add_stage(self._downscale_stage)
        self._combine_velocity_stage = CombineVelocityStage(self)
        add_stage(self._combine_velocity_stage)

        # Add an upscale/downscale stage in case we render at a different resolution
        if abs(1 - self.settings["pipeline.resolution_scale"]) > 0.005:
            self._upscale_stage = UpscaleStage(self)
            add_stage(self._upscale_stage)
 Inits the commonly used stages, which don't belong to any plugin,
        but yet are necessary and widely used. 
metadrive/render_pipeline/rpcore/render_pipeline.py