How to make sure unique, randomly spawned, instantiated prefabs only spawn once

Questions & Answers
1

I have a game with hundreds of unique prefab items that need to be randomly generated into the scene. The problem I’m running into is that I can’t seem to figure out how to prevent my spawner from creating duplicates from the array I’ve generated.

I wrote a bunch of if/else statements trying to compare my random array value but I ran into a chicken and the egg problem where I couldn’t compare a the array’s int because it hadn’t been instantiated yet and I couldn’t compare the int because it had already been instantiated.

I also tried to compare names and destroy, and search for the “Clone” tag and destroy (both seem round about - any guidance would be great :slight_smile:

void Start()
	{
		
		myObjects = Resources.LoadAll<GameObject>("Prefabs");
	

		startPosition = transform.position;

	}

	void SpawnRandomObject() 
	{	
		//spawns item in array between position number 0 thru 49
		int whichItem = Random.Range (0, 49);
	
		//replace gameObject set with script that gathers prefabs from folder
		GameObject myObj = Instantiate (myObjects [whichItem]) as GameObject;

		myObj.transform.position = transform.position;
    }

    //my efforts were something similar to this
    void Awake()
{
    var clones:GameObject = GameObject.FindWithTag("Clone"));

    if(clones)
    {
	Destroy(clones.GameObject);
    }
}

Thanks! :slight_smile:

2

Have two lists, A and B. A contains all the unchosen objects, so starts off like your myObjects array and B starts empty. Pick an object from list A, and move it to list B. Over time A will get smaller, and B will get bigger. When you’re done with an object, move it back from B into A. (Or, if you never want the object used again, into a new list C which stores the used objects.)