Create high-precision occlusion areas

Use the Occlusion Area component to define View Volumes in the occlusion cullingA process that disables rendering GameObjects that are hidden (occluded) from the view of the camera. More info
See in Glossary system. View Volumes are areas of the SceneA Scene contains the environments and menus of your game. Think of each unique Scene file as a unique level. In each Scene, you place your environments, obstacles, and decorations, essentially designing and building your game in pieces. More info
See in Glossary where the CameraA component which creates an image of a particular viewpoint in your scene. The output is either drawn to the screen or captured as a texture. More info
See in Glossary is likely to be located at runtime. At bake time, Unity generates higher precision data within View Volumes. At runtime, Unity performs higher precision calculations when the Camera’s position is within a View Volume.

If you have not defined any View Volumes in your Scene, Unity creates a View Volume at bake time that contains all Scene geometry that is marked as Occluder Static or Occludee Static. This can lead to unnecessarily large data size, slow bake times and resource-intensive runtime calculations in large or complex Scenes. To avoid this, place Occlusion Areas in your Scene to define View Volumes for the areas where the Camera is likely to be.

Using an Occlusion Area component to define a View Volume

1. Add an Occlusion Area component to an empty GameObjectThe fundamental object in Unity scenes, which can represent characters, props, scenery, cameras, waypoints, and more. A GameObject’s functionality is defined by the Components attached to it. More info
   See in Glossary in your Scene
2. In the InspectorA Unity window that displays information about the currently selected GameObject, asset or project settings, allowing you to inspect and edit the values. More info
   See in Glossary window, configure the Size property so that the bounding volumeA closed shape representing the edges and faces of a collider or trigger.
   See in Glossary covers the desired area
3. In the Inspector window, enable Is View Volume

Occlusion Area component reference

OcclusionArea