Render.IsVisible always show visible even when off camera.

Hi!

This is my code, it is not working yet. I'm trying to tell if the children of the component of the children is visible or not but the Renderer always tells me that it is visible in the Debug.Log.

I also check if it was looking at the right Renderer which he seems to be doing.

In the end I want to run code when the children of the gameobject became invisible. If you have a better idea how to let me know !

Thanks and have a nice day! :)

 public class teleport2 : MonoBehaviour {
 
     public Renderer mesh;
 
     // Use this for initialization
     void Start () {
         mesh = GetComponentInChildren<Renderer>();
         
     }
     
     // Update is called once per frame
     void Update () {
         Debug.Log(mesh.isVisible);
         Debug.Log(mesh.name);
 
     }
 
     private void OnBecameInvisible()
     {
         var cam = Camera.main;
         var viewportPosition = cam.WorldToViewportPoint(transform.position);
         var newPosition = transform.position;
 
         if (viewportPosition.x >1 || viewportPosition.x < 0)
         {
             newPosition.x = -newPosition.x;
         }
 
         if (viewportPosition.y > 1 || viewportPosition.y < 0)
         {
             newPosition.y = -newPosition.y;
         }
 
         transform.position = newPosition;
 
     }
 }