private void Update()
 {
     if (prefabManager != null && prefabManager.isActiveAndEnabled)
     {
         Rigidbody rb;
         for (int i = 0; i < _enteredInstances.Count; i++)
         {
             if (!IsInsideCollider(_enteredInstances[i]))
             {
                 rb = _enteredInstances[i].GetComponent <Rigidbody>();
                 if (rb != null && !rb.IsSleeping())
                 {
                     continue;
                 }
                 GPUInstancerAPI.EnableInstancingForInstance(prefabManager, _enteredInstances[i]);
                 _enteredInstances.Remove(_enteredInstances[i]);
                 i--;
             }
             else if (_enteredInstances[i].state != PrefabInstancingState.Disabled)
             {
                 prefabManager.DisableIntancingForInstance(_enteredInstances[i]);
             }
         }
     }
 }