Occlusion Map
In 3D graphics, occlusion refers to light being blocked by objects. Even in PBR, ambient light is reflected in weird ways where it should be occluded. Occlusion Map (Occlusion Map) can add shadows to these places.
Most of the 3D models will have Occlusion Map. Using occlusion maps can make the surface of the object look more realistic, and can also increase the detailed shadows that cannot be represented by Base Map and Bump Mapping.
We can adjust the parameters of the occlusion map through the Occlusion Map property in the Inspector panel of the material. The following is a comparison of the effect after the Occlusion Map is changed from 1 to 0:
It can be seen that when the parameter of the occlusion map is 1, there will be more shadow details, and the neckline will look closer to reality.
Use Microsurface Map to increase details (Microsurface Map)
If we take a closer look at objects with smooth surfaces in the real world, such as fingerprints on the screen of a mobile phone, or scratches on a coffee cup. In 3D models, if you want to achieve a similar effect, you can use microsurface maps to achieve.
Or take the actual example as an example. In the Material Inspector panel of Unity, we find Detail Inputs (we have been using Surface Inputs before ), find the Normal map below this, let’s adjust the parameters and compare them to see the effect:
It can be seen that when the parameters of the microsurface texture become larger, the skin of the character becomes more grainy.