Ok. I figured this out. It’s because I has set roughness to 1.
I remember putting a ambient light as a shader input for the directional light shader, but I don’t remember putting in any convenient way to set it. You can still do:
deferred_renderer.set_filter_input(stage_name='final_light', name='ambient', value=Vec3(0.1, 0.1, 0.2))
Thanks. It works.
How do I setup textures for animated sprites which was made with egg-texture-cards?