My journey becoming a Unity game developer: Environment & Lighting-Occlusion Map
Objective: Using the Occlusion Map on the textures applied to the game object. Adjusting the occlusion to manipulate shadows on the object.
The occlusion map is used to provide information about which areas of the 3D model should receive high or low indirect lighting giving it false shadows. Indirect lighting comes from ambient lighting and reflections, so parts of your game object like a crack or a fold would not realistically receive much indirect light.
We’re going to use a door as an example of occlusion. Go to Door Start and click on the Front Door game object. Under Shader, go in Albedo and select the DoorTextureSurface_Color texture for the door’s initial appearance. Then go to Occlusion and select the DoorTextureAmbient_Occlusion texture for showing how the ambient lighting is reflecting off the door.
As we slide the Occlusion slider from zero to 1, we can see a non-shadow look moving on the door to a slight shadow reflecting on certain parts of the door.
If we look at the DoorTextureAmbient_Occlusion map, the texture is a greyscale image with light and dark areas. The light areas is where light will be able to reflect, and the dark areas is where there will be no light reflections whatsoever.
Occlusion is a wonderful tool to take advantage of the area’s indirect lighting to give little details in the 3D models extra life to the scene.