CODEWITHSUNDEEP
c#unity-game-engine
Vivek Negi
Vivek Negi

Reputation: 51

Stop Object from instantiating multiple times in Update using bool

This is the script. I want the object to instantiate only once every time the y position is a multiple of 4. But the object gets instantiated multiple times as long as the y position is stuck at 4. I want to it to instantiate only once. Here's the script.

public GameObject obj;
bool check = true;


private void Update()
{

    if (Mathf.Round(transform.position.y) % 4 == 0 && check)
    {
        check = false;
        Spawn();

    }
}

public void Spawn()
{

    Instantiate(obj, new Vector3(transform.position.x, transform.position.y), Quaternion.identity);
    check = true;

}

Thank You.

Upvotes: 1

Views: 526

Answers (2)

FCin
FCin

Reputation: 3925

Single bool is not enough, because you want to instantiate one object multiple times. You want to check if it was already instantiate in this position.

  public GameObject obj;
  float lastInstPos = 0;


    private void Update()
    {
        var currPos = Mathf.Round(transform.position.y);
        if (currPos % 4 == 0 && currPos != lastInstPos)
        {
            lastInstPos = currPos;
            Spawn();

        }
    }

    public void Spawn()
    {

        Instantiate(obj, new Vector3(transform.position.x, transform.position.y), Quaternion.identity);

    }

If you want to include 0, then make the lastInstPos something arbitrary, e.g. lastInstPos = float.MinValue

Update: This solution assumes that y either increases or decreases, but doesn't do both.

Upvotes: 1

Patrick Artner
Patrick Artner

Reputation: 51683

Simply use the return value of Instantiate and put each Instance into a Dictionary that has its y position as key - before instatiating check if this y position is already a key in the dictionary:

public GameObject obj;

private Dictionary<int, GameObject> myInst = new Dicitionary<int, GameObject>();


private void Update()
{
    int pos = (int)Mathf.Round(transform.position.y);

    if (pos % 4 == 0 && !myInst.ContainsKey(pos)) // check if key exists
    {
        myInst[pos] = Spawn();  // add gameObject to dictionary 
    }
}

// return the gameObject you spawned
public GameObject Spawn()
{
    return Instantiate(obj, new Vector3(transform.position.x, transform.position.y), Quaternion.identity);
}

That way you know the exact y coordinate of each instantiated object.

If you do not need the Instance-GameObject as well you could get away simply with a Hashset<int> of y-positions that you instantiated. Dictionary as well as Hashsets have very fast O(1) Key Lookups, store a ref to your Instanciated object takes not much space and is easier to retrieve here then by searching (if you ever need them at all)

Upvotes: 0

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