Question Instantiateing Objects After Certain Amount Of Time

Hello , we are trying to do timing spawner with this code. However it just constantly spawns objects nonstop.
We dont want to use invoke because we will make an upgrade system that lowers the cooldown of spawn time
How can we fix this?
public class Street1 : MonoBehaviour{
bool cooldown = false;
public Transform spawnLocation;
public GameObject car1;
public GameObject car2;
public GameObject car3;
public GameObject[] cars = new GameObject[3];
void Start(){
cars[0] = car1;
cars[1] = car2;
cars[2] = car3;}

void Update()
{
if (cooldown == false)
{
spawnCar();
}
}






public void WaitForSeconds(float time){
float x = 0;

while(x<=time)
x+=Time.deltaTime;

if (x >= time) {
cooldown = false;

}
}

public void spawnCar(){
cooldown=true;
Instantiate(cars[UnityEngine.Random.Range(0,3)],new Vector3(spawnLocation.position.x,spawnLocation.position.y,spawnLocation.position.z),new Quaternion());
WaitForSeconds(UnityEngine.Random.Range(8,11));
}

}

 

If you post a code snippet, ALWAYS USE CODE TAGS:

How to use code tags: https://forum.unity.com/threads/using-code-tags-properly.143875/

You may edit your post above.

Time to start debugging! Here is how you can begin your exciting new debugging adventures:

You must find a way to get the information you need in order to reason about what the problem is.

Once you understand what the problem is, you may begin to reason about a solution to the problem.

What is often happening in these cases is one of the following:

- the code you think is executing is not actually executing at all
- the code is executing far EARLIER or LATER than you think
- the code is executing far LESS OFTEN than you think
- the code is executing far MORE OFTEN than you think
- the code is executing on another GameObject than you think it is
- you're getting an error or warning and you haven't noticed it in the console window

To help gain more insight into your problem, I recommend liberally sprinkling

Debug.Log()

statements through your code to display information in realtime.

Doing this should help you answer these types of questions:

- is this code even running? which parts are running? how often does it run? what order does it run in?
- what are the names of the GameObjects or Components involved?
- what are the values of the variables involved? Are they initialized? Are the values reasonable?
- are you meeting ALL the requirements to receive callbacks such as triggers / colliders (review the documentation)

Knowing this information will help you reason about the behavior you are seeing.

You can also supply a second argument to Debug.Log() and when you click the message, it will highlight the object in scene, such as

Debug.Log("Problem!",this);

If your problem would benefit from in-scene or in-game visualization, Debug.DrawRay() or Debug.DrawLine() can help you visualize things like rays (used in raycasting) or distances.

You can also call Debug.Break() to pause the Editor when certain interesting pieces of code run, and then study the scene manually, looking for all the parts, where they are, what scripts are on them, etc.

You can also call GameObject.CreatePrimitive() to emplace debug-marker-ish objects in the scene at runtime.

You could also just display various important quantities in UI Text elements to watch them change as you play the game.

Visit Google for how to see console output from builds. If you are running a mobile device you can also view the console output. Google for how on your particular mobile target, such as this answer or iOS: https://forum.unity.com/threads/how-to-capturing-device-logs-on-ios.529920/ or this answer for Android: https://forum.unity.com/threads/how-to-capturing-device-logs-on-android.528680/

If you are working in VR, it might be useful to make your on onscreen log output, or integrate one from the asset store, so you can see what is happening as you operate your software.

Another useful approach is to temporarily strip out everything besides what is necessary to prove your issue. This can simplify and isolate compounding effects of other items in your scene or prefab.

Here's an example of putting in a laser-focused Debug.Log() and how that can save you a TON of time wallowing around speculating what might be going wrong:

https://forum.unity.com/threads/coroutine-missing-hint-and-error.1103197/#post-7100494

"When in doubt, print it out!(tm)" - Kurt Dekker (and many others)

Note: the

print()

function is an alias for Debug.Log() provided by the MonoBehaviour class.

 

Your WaitForSeconds routine is not actually waiting for seconds before setting

cooldown

to false. The entire while loop is executing in one frame, meaning that

cooldown

is getting set to true and false in a single frame. This leads to the "spawn every frame" behavior you're seeing.

It appears that you're trying to do something akin to a Coroutine without actually using a Coroutine. The Coroutine version of your code looks something like this:

Code (CSharp):

1.  
2. // Start, not Update!
3. void Start () {
4.   StartCoroutine(SpawnCar());
5. }
6.  
7. IEnumerator SpawnCar () {
8.   while( true ) {
9.     // spawn the car
10.     /* omitted for brevity */
11.     // wait to spawn the next car
12.     yield return new WaitForSeconds(UnityEngine.Random.Range(8,11));
13.   }
14. }

Also, please use code tags in the future. It is a lot more difficult to read code when it is pasted directly into the forum post.

 

Line 7 "Spawn the Car" has to be after your yield or it isn't going to delay the spawn at all.

If you just need to "do something a little later," I always use my CallAfterDelay class for delayed action.

https://gist.github.com/kurtdekker/0da9a9721c15bd3af1d2ced0a367e24e

See usage notes at bottom below gist code.

 

You are correct. A typo, as I intended to include a while loop in the snippet but forgot! I have edited the post.