Having now established a resolution and Lightmap Size, we should specify baking details to improve the quality and appearance of our lightmaps. To do this, enable Ambient Occlusion and tweak the Max Distance field until you get the volumetric effect desired. This requires rebaking. Ambient Occlusion is sometimes called Contact Shadows, because it generates shadows where two or more solid bodies meet, such as the floor meeting the wall, or crevices and cracks. This creates a volume effect, enhancing the 3D feel of a scene:
Enabling Ambient Occlusion
In addition, enable Final Gather. Set the Ray Count to 256. Final ...
