How can I check FindGameObjectsWithTag during runtime? - unity3d

Question

I'm having troubles with my enemy NavMeshAgent AI, First it searches for GameObjects tagged with "Defenses", then I set the first destination based in how close the defense is by my enemy, when the defense is destroyed, the array value is increased by one and it changes the destination to the next defense.
My problem is, my player can create (Instance) new defenses during the game, when all my defenses are destroyed, my enemy turns crazy, so, i need a way to add those new defenses to my array, below is my enemy script.
public class NavMeshEnemy : MonoBehaviour
{
[Header("References", order = 0)]
[SerializeField] NavMeshAgent enemyAgent;
[Space(10)]
[SerializeField] GameObject[] destinations;
[Space(10)]
[SerializeField] float distanceObjects;
[SerializeField] int arrayElements = 0;
void Awake()
{
enemyAgent = GetComponent<NavMeshAgent>();
destinations = GameObject.FindGameObjectsWithTag("Defenses");
}
void Start()
{
destinations = destinations.OrderBy((d) => (d.transform.position - this.transform.position).sqrMagnitude).ToArray();
}
void Update()
{
distanceObjects = Vector3.Distance(this.transform.position, destinations[arrayElements].transform.position);
enemyAgent.destination = destinations[arrayElements].transform.position;
CheckArray();
}
void CheckArray()
{
if (destinations[arrayElements].gameObject.activeInHierarchy == false)
{
if (arrayElements < destinations.Length - 1)
{
arrayElements++;
enemyAgent.destination = destinations[arrayElements].transform.position;
}
else
{
arrayElements = 0;
}
}
}
}
Thank you for reading! :)

Answer 1

I would rather implement a component on your prefab with a static list like e.g.
public class NavMeshDestination : MonoBehaviour
{
public static HashSet<Transform> existingDestinations = new HashSet<Transform>();
private void Awake()
{
if(!existingDestinations.Contains(this)) existingDestinations.Add(this);
}
private void OnDestroy()
{
if(existingDestinations.Contains(this)) existingDestinations.Remove(this);
}
}
And then don't even go by tag but simply do
public class NavMeshEnemy : MonoBehaviour
{
[Header("References", order = 0)]
[SerializeField] NavMeshAgent enemyAgent;
[Space(10)]
[SerializeField] float distanceObjects;
[SerializeField] int arrayElements = 0;
void Awake()
{
if(!enemyAgent) enemyAgent = GetComponent<NavMeshAgent>();
}
void Update()
{
destinations = NavMeshDestination.existingDestinations.OrderBy(d => (d.transform.position - this.transform.position).sqrMagnitude).ToArray();
distanceObjects = Vector3.Distance(this.transform.position, destinations[arrayElements].transform.position);
enemyAgent.destination = destinations[arrayElements].transform.position;
CheckArray();
}
void CheckArray()
{
if (destinations[arrayElements].gameObject.activeInHierarchy == false)
{
if (arrayElements < destinations.Length - 1)
{
arrayElements++;
enemyAgent.destination = destinos[arrayElements].transform.position;
}
else
{
arrayElements = 0;
}
}
}
}
Note however that this still won't fix your issues with no available destination. So you probably should stop the execution if the array is empty like
if(NavMeshDestination.existingDestinations.Count == 0)
{
// Stop the enemyAgent
return;
}