public void OnPreCull()

In the Built-in Render Pipeline, Unity calls on MonoBehaviours that are attached to the same GameObject as an enabled Camera component, just before performing the culling operation that determines what that Camera can see. For a full description and code example, see MonoBehaviour.OnPreCull(). For similar functionality that does not require the script to be on the same GameObject as a Camera component, see Camera.onPreCull. If you're using a Scriptable Render Pipeline, for example the Universal Render Pipeline, use RenderPipelineManager instead.