Prevent overlapping of spawned object over AI and Player

Questions & Answers
1

A collectible is being instantiated every time a player or AI overlaps the collectible, but sometimes the player and AI are above each other and the collectible is instantiated twice. So, I’m wandering how would I prevent the collectible from being instantiated over the player or the AI. I know about Physics2D.OverlapCircle but I don’t know how to implement it. Here’s my spawn code:

public class DeleteAndSpawn : MonoBehaviour
{
    
    public GameObject Collectable;
    UIManager UiManagerVar;
    Vector2 randomCollectPosition;
    Collider2D radius;
    //public float ScanRadius;
    public void Update()
    {
       
        UiManagerVar = GameObject.Find("Canvas").GetComponent<UIManager>();
    }

    private void OnTriggerEnter2D(Collider2D collision)
    {
        if (collision.tag == "Enemy")
        {
            Vector2 randomCollectPosition = new Vector2(Random.Range(-4, 4), Random.Range(-4, 4));
            Instantiate(Collectable, randomCollectPosition, Quaternion.identity);
            Destroy(gameObject);
            UiManagerVar.UpdateofNumberEnemy();
        }

        else if (collision.tag == "Player")
        {
            Vector2 randomCollectPosition2 = new Vector2(Random.Range(-4, 4), Random.Range(-4, 4));
            //if collider is equal to he circle dont instantiate
            Instantiate(Collectable, randomCollectPosition2, Quaternion.identity);
           /*Collider2D radius = Physics2D.OverlapCircle(transform.position, ScanRadius, exclude);
            if (radius != null)
              {
                Destroy(gameObject);
                }*/
            Destroy(gameObject);
            UiManagerVar.UpdateofNumber();
        }   
    }
}
2

The performant way would be:

using UnityEngine;

public class DeleteAndSpawn : MonoBehaviour
{
	public GameObject Collectable;
	public float ScanRadius;
	UIManager UiManagerVar;
	Vector2 randomCollectPosition;
	Collider2D radius;

	void Update ()
	{
		UiManagerVar = GameObject.Find("Canvas").GetComponent<UIManager>();
	}

	void OnTriggerEnter2D (Collider2D collision)
	{
		if (collision.tag == "Enemy")
		{
			Vector2 randomCollectPosition = new Vector2(Random.Range(-4, 4), Random.Range(-4, 4));
			Instantiate(Collectable, randomCollectPosition, Quaternion.identity);
			Destroy(gameObject);
			UiManagerVar.UpdateofNumberEnemy();
		}

		else if (collision.tag == "Player")
		{
			Transform playerTrs = collision.transform;
			Vector2 playerPosition = playerTrs.position;
			Vector2 randomCollectPosition2;
			do
			{
				randomCollectPosition2 = new Vector2(Random.Range(-4, 4), Random.Range(-4, 4));
			} while ((randomCollectPosition2 - playerPosition).sqrMagnitude <= ScanRadius * ScanRadius);
			// } while (Vector2.Distance(randomCollectPosition2, playerPosition) <= ScanRadius);
			Instantiate(Collectable, randomCollectPosition2, Quaternion.identity);
			Destroy(gameObject);
			UiManagerVar.UpdateofNumber();
		}   
	}
}

Keep in mind that this way doesn’t take into account the collision shape of the player and just uses the player’s position.
Using Physics2D.OverlapCircle the answer would be:

using UnityEngine;

public class DeleteAndSpawn : MonoBehaviour
{
	public GameObject Collectable;
	public float ScanRadius;
	UIManager UiManagerVar;
	Vector2 randomCollectPosition;
	Collider2D radius;

	void Update ()
	{
		UiManagerVar = GameObject.Find("Canvas").GetComponent<UIManager>();
	}

	void OnTriggerEnter2D (Collider2D collision)
	{
		if (collision.tag == "Enemy")
		{
			Vector2 randomCollectPosition = new Vector2(Random.Range(-4, 4), Random.Range(-4, 4));
			Instantiate(Collectable, randomCollectPosition, Quaternion.identity);
			Destroy(gameObject);
			UiManagerVar.UpdateofNumberEnemy();
		}

		else if (collision.tag == "Player")
		{
			Vector2 randomCollectPosition2;
			LayerMask whatIsPlayer = LayerMask.GetMask(LayerMask.LayerToName(collision.gameObject.layer));
			do
			{
				randomCollectPosition2 = new Vector2(Random.Range(-4, 4), Random.Range(-4, 4));
			} while (Physics2D.OverlapCircle(randomCollectPosition2, ScanRadius, whatIsPlayer) != null);
			Instantiate(Collectable, randomCollectPosition2, Quaternion.identity);
			Destroy(gameObject);
			UiManagerVar.UpdateofNumber();
		}   
	}
}

Also, you might already know these last two notes but in case it helps: Random.Range(-4, 4) generates a random integer between -4 and 3 (it can also be equal to those -4 or 3). The maximum value is 3 because the second parameter is “exclusive”. Also, Random.Range(-4f, 4f) will generate a random float between -4 and 4.