Calling a function only once in Update

Question

Hi everyone, I'm having an inssue with my script here:

 var barDisplay : float = 3;
 var timeLeft : float = .5;  //amount of time on timer
 static var finishTimer = false; //i made this global so you can access from other scripts
 static var timerStarted = false;
 
 
 
 function OnTriggerEnter (col : Collider){
         if(col.name == "Player")
         
         GameObject.Find("DoubleRockets").GetComponent("gunscript");
         gunscript.initialSpeed += 200;
         timerStarted = true;
         
         
         }
         
             
 function Update() {
 
     if (timerStarted == true)
         timeLeft -= Time.deltaTime;
     
     if (timeLeft <= 0.0f)  
     {
         GameObject.Find("DoubleRockets").GetComponent("gunscript");
         gunscript.initialSpeed -= 200;
         Destroy(gameObject);
     }
     
 }

The problem is that the gunscript.initialSpeed -= 200; part is being called more than once before the gameobject is destroyed. How can I make sure this function gets called only once?

Answer 1

Best Answer

Answer by Meltdown · Aug 10, 2011 at 09:10 PM

static var gunSpeedReduced = false;

 if (timeLeft <= 0.0f)  
     {
         GameObject.Find("DoubleRockets").GetComponent("gunscript");
 
         if(gunSpeedReduced == false)
         {
           gunscript.initialSpeed -= 200;
           gunSpeedReduced = true;
         }
         
         Destroy(gameObject);
     }

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Answer 2

Answer by 4illeen · Aug 10, 2011 at 08:23 PM

You could always create a boolean variable equal to false at first and make an if statement which will check if it's false. Inside the if statement call your function and make the boolean equal to true

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Noah-1 · Apr 20, 2012 at 09:25 PM 0

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Exellent solution my friend!!

mohammad-alavi-74 · Mar 27, 2016 at 07:15 PM 0

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really helped! like!

VRP360 · Apr 16, 2019 at 07:15 AM 0

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But this way, it will never be false again, or am I wrong? How could you make the boolean variable false again? Thanks in advance!

highpockets VRP360 · Apr 16, 2019 at 07:46 AM 0

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I think the idea of the original poster was to just call the function once, so he/she wouldn’t need to make it false again, but of course there is a way to make it false again, though. You would have to have another condition to be met to make it true. For example x amount of seconds go by, an object rotates 360 degrees about the y axis, transform.position == endPos, etc.. It just depends on your case, if you explain what you want to do, I can provide a solution. But if you want to do the same as the original poster (call a function just once inside update) than you never need to change the Boolean back to true. Personally, I would not make the Boolean at all and I would just start a coroutine when the trigger is entered, and call the function after yield return new WaitForSeconds(secondsToWait); is finished

Answer 3

Answer by Ali_unity · May 31, 2018 at 07:54 AM

 bool MyFunctionCalled = false;
 
 void Update()
 {
       If(MyFunctionCalled==false)
     {
         MyFunctionCalled = true;
         Do Your Stuff Here And It Will Be Only Done Once !.
     }
 
 }

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thegreatkoala · Aug 18, 2018 at 05:08 PM 0

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Thank you for that answer, it was a great help for me :)

Ajparker · Nov 16, 2020 at 12:46 PM 0

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THANK YOU !!

Answer 4

Answer by DGArtistsInc · Aug 10, 2011 at 08:15 PM

If you want to call the function only once then create your own function or use function start. Anything under the Function Update is called every frame. Which is every second.

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Eric5h5 · Aug 11, 2011 at 06:38 AM 0

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Every frame is as often as the computer can manage, not every second. Unless you're only getting 1 fps.

DGArtistsInc · Aug 15, 2011 at 01:53 PM 0

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yeah your right thats what i meant

Answer 5

Answer by Atrius · Apr 21, 2012 at 05:43 AM

You should simply be using Invoke() for something like this. Pass it the function to call and the time period and it'll do the rest for you. You can call this on your component or whatever object you need.

No need to track the time and things manually unless you need to track it in increments, and even then if you need increments use InvokeRepeating() since it's easily cancelled.

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Calling a function only once in Update

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