public void OnBecameVisible()

This message is sent to all scripts attached to the renderer. and MonoBehaviour.OnBecameInvisible() are useful to avoid computations that are only necessary when the object is visible. The Scene view camera in the Unity Editor is treated like a regular camera for visibility checks, so can be called when objects are visible in the Scene view, even if the application isn't running. Scripts that execute in Edit mode can check Application.isPlaying before running important logic in to avoid unintended behavior in the Editor. can be a coroutine.

// Enables the behaviour when it is visibleusing UnityEngine;using System.Collections;public class ExampleClass : MonoBehaviour{    void OnBecameVisible()    {        enabled = true;    }}