Delay in Instantiate only runs once

Questions & Answers
1

Hello all! I have a spawning system that checks the maximum spawn limit by randomising between two locations and if its below it, it will spawn more zombies.

At the moment it all works good except and the start of the game as it starts spawning it spawns the zombies at the random locations however all at once which makes them explode (which does look pretty cool) but its not what I want. So I inserted a delay using

yield WaitForSeconds(5);

however it only seems to run the delay code once then never again so it waits for 5 seconds, then spawns the exploding zombies. This is my code;

#pragma strict
//Integers
static var MaxAI = 5;
var EnemysSpawned = 0;
static var EnemysKilled = 0;
var spawnLocation = 1;

//boolean
var spawnForLevel = true;

//Transforms
var spawnLocationR : Transform;
var spawnLocationL : Transform;
var locationToSpawn : Transform;

//Enemys
var Zombie : Transform;

function Update ()
{
	if (spawnForLevel == true)
	{
		if (EnemysSpawned < Spawning_Rate.MaxAI)
		{
			randomGens();
			Delay();
			var spawnZombie = Instantiate (Zombie, locationToSpawn.position, Quaternion.identity);
			EnemysSpawned += 1;
		}
		
		if (EnemysSpawned == Spawning_Rate.MaxAI)
		{
			spawnForLevel = false;
		}
	}
}

//This is the delay code, it only seems to run this once then skip it every other time

function Delay()
{
	yield WaitForSeconds(5);
}

//Randomise Code
function randomGens ()
{
	//Position
	var randPos = Random.Range(0, 1);
	spawnLocation = randPos;
	
	switch (EnemysSpawned)
	{
		case 0:
			locationToSpawn = spawnLocationR;
		break;
		case 1:
			locationToSpawn = spawnLocationL;
		break;
	}
}

I have also tried using LateFunction but no luck how can I make it run the code more than once? thank you!

2

I’m not entirely certain how Coroutines behave in UnityScript, but I’m pretty sure that your call to Delay() just spawns a coroutine that waits for 5 seconds and then ends, doing nothing. At the same time, execution continues immediately after the line Delay(), without actually delaying. So in the version of the code you posted, there shouldn’t even be a delay, there will be one zombie spawned every frame.

I think the easy fix is to just insert the yield keyword before your call, compare to the documentation page. Also, you need to move the counter increment before the call to Delay, so it registers as “a zombie will be spawned”, and prevents you from indefinitely spawning zombies until after the delay (because your counter would remain 0 the whole time). Move “randomGens” after the delay, for a similar reason - otherwise locationToSpawn might change in the meantime, overwriting the value for all zombies that are still in the “spawn queue”.

     EnemysSpawned += 1;
     yield Delay();
     randomGens();
     var spawnZombie = Instantiate (Zombie, locationToSpawn.position, Quaternion.identity);
3

In the end I still don’t know why the yield function doesn’t work, so instead I created a small timer

var Timer = 300;

and a boolean

var TimerGo = false;

and then put in

if (TimerGo == true)
{
     Timer -=1;
     if (Timer < 0)
     {
          spawnEnemy = true;
          Timer = 300;
     }
}