Minecraft wiki entry for Light, associated text: Smooth lighting is a lighting engine that blends light levels across block faces and darkens corners using ambient occlusion to add semi-realistic shadows and glowing from light sources. It affects only rendered brightness, not the light level, so it has no effect on mob spawning or crop growth. It is set on by default. Paintings, item frames[2] and water surfaces[3] are unaffected.‌[Java Edition only]