Spawning from array not working properly

Unity Engine
1

Hi guys,

I’m having some trouble with spawning from an array I have it working almost perfectly however every now and again it spawns 2-4 objects when it should only spawn one, anybody got any ideas why this happens? Heres my scripts:

static var spawningMap: boolean = false;
var objectsToSpawn: GameObject[ ];

function FixedUpdate()
{
	//check if spawning item
	if(spawningMap == true)
	{
		spawnMap();
	}
}

function spawnMap()
{
				
	//spawns objects from array
	var thingToSpawn: int = Random.Range(0, objectsToSpawn.length);
	Instantiate(objectsToSpawn[thingToSpawn], transform.position, transform.rotation);
}

var speed: int = 80;

function Update() 
{
	var amtToMove = speed * Time.deltaTime;
	transform.Translate(Vector3.back * amtToMove,Space.World);
		
	if(transform.position.z < -250)
	{
		Destroy (gameObject);
	}
	
	if(transform.position.z <= 101.443)
	{
		SpawnControllerMap.spawningMap = true;
	}
	else if(SpawnControllerMap.mapSpawned == true)
	{
		SpawnControllerMap.spawningMap = false;
	}
}

Any help would be appreciated.

Thanks

2

I’m guessing you want to spawn once per frame. If the problem is that you get multiple spawns per frame, I am going to say your problem is putting the spawning code inside FixedUpdate() which can run multiple times a frame. Sometimes FixedUpdate() will not even run in a frame.

This is because FixedUpdate() occurs when the physics is updated, and Update() happens when the screen is updated. These do not happen at the same time.

I do not see any physics happening so the fix would be to put everything inside Update() and get rid of the FixedUpdate().

3

You need to stop your condition in the Update function from setting that static var more that once. Hook up a Debug or print line in your conditions to troubleshoot what is true more than once.

I like to use a simple int to stop a condition

(eg)

if((something<=something)(someInt==0)) {
  someInt = 1; //Upper condition is now locked till reset
  //Then the code to be called once
}
4

There’s a little mistake in the else if, I amended it here thats what it says still getting the same error. If I use just the Update function instead of just spawning 1 it always spawns 2 pieces, I will have to give the other thing a try with the int hanks for the help, anymore help would be appreciated

else if(SpawnControllerMap.spawningMap == true)
{
SpawnControllerMap.spawningMap = false;
}