How can I Instantiate and do it in a random spot in a random spot?

Question

Hi! I need to Instantiate a prefab in a random spot, those spots are marked by prefabs. I have tried to instantiate it normally, but even that won't work. Here is the instantiate code:

 #pragma strict
 
 var myString : String = "5";
 var myInt : int = parseInt(myString);
 var SpawnSpot : Transform;
 var spawnMonster;
 var choosingIsActive : boolean = true;
 var Monster : Transform;
 
 function Start () {
 
 }
 
 function Update () {
     
 }
 
 function OnGUI()
   {
       if(choosingIsActive)
       {
        myString = GUILayout.TextField(myString, 2);
        myString = Regex.Replace(myString, "[^0-9]", "");
        
            if(GUI.Button(Rect(Screen.width/2.1, Screen.height/2.1, 106, 50), "Play!"))
            {
                    choosingIsActive = false;
                 spawnMonster = Instantiate("PlayerController", transform.position, transform.rotation);
            }
        }
   }

Here is the error I get: Assets/Scripts/Temples Choosing Menu.js(28,59): BCE0023: No appropriate version of 'UnityEngine.Object.Instantiate' for the argument list '(String, UnityEngine.Vector3, UnityEngine.Quaternion)' was found.

The main of the code to look at is line 28.

How can I fix this?

Also, is there a method that I can use for choosing a random spawn spot out of 6 placed around my map? I heard something about using Random.Range to figure it out, but I can't understand how to use this. Honestly, I need all the help I can get for this right now! I'm a new indie developer! I have searched everywhere online and the closest I have come to an answer is how to move it at to a random number/coordinate.

Thanks in advance!

-The_Unity_Game_Developer.

PS. If possible, I need any code to be given in JavaScript (UnityScript). Thanks again!

Answer 1

Answer by YoungDeveloper · Jan 03, 2015 at 04:21 PM

Simply cast the object to gameobject.

spawnMonster = (GameObject)Instantiate("PlayerController", transform.position, transform.rotation);
Your arguments aren't correct Instantiate takes gameobject as first param, but you are passing a string "PlayerController";

Here's a simple example.

 public GameObject prefab; //add from inspector
 
 private void Start(){
     GameObject instance = (GameObject)Instantiate(prefab, new Vector3(1,2,3), Quaternion.Euler(0, 30, 0));

 }

You can also create an empty gameObject using

GameObject obj = new GameObject();

http://docs.unity3d.com/ScriptReference/Object.Instantiate.html

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The_Unity_Game_Developer · Jan 03, 2015 at 05:01 PM 0

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Thank you so much! Will it work for the position and rotation if I use a variable? EG: SpawnSpot.transfom.position, SpawnSpot.transform.rotation

Also, now all I need is an answer to my second question. How do I do the random spawn spot thing? Please feeder to original question for more info.

YoungDeveloper · Jan 03, 2015 at 06:07 PM 0

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Yes of course it will, 3rd param takes a quaternion, i used .Euler to use simple vector3 as a rotation, as it's more understandable.

There are two easy ways to do it, either create a public transform array and fill it with empty gameobjects which will server as spawnpoints. Then use Random.Range to select random array slot and take that position.

 public Transform[] spawnPoints; //define and add from inspector
 
 public void Spawn(){
     int indx = Random.Range(0,spawnPoints.Length-1);
     Vector3 spawnPosition = spawnPoints[indx].position;
 
     //spawn
 }

Either use actual Random spawning, but then again just use Random.Range()

 Instantiate(prefab, new Vector3(Random.Range(0f,10f),0,Random.Range(0f,10f)), Quaternion.Euler(0, 30, 0));

The_Unity_Game_Developer · Jan 03, 2015 at 07:04 PM 0

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Ok that's perfect! Thanks! Just one more thing. How would these code lines be written in javascript? I notice they're in CSharp. Would they just be the same in UnityScript as they would be in C#? Thanks again!

The_Unity_Game_Developer · Jan 03, 2015 at 08:19 PM 0

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Ok. Another problem. The code I used for the instantiate was the one using .Euler and new Vector3. However, these make the guy spawn at a different point, spawning him in 'the void'. How can I make the position and the rotation act with the SpawnPoints?

I'm using this code version you made:

 GameObject instance = (GameObject)Instantiate(prefab, new Vector3(1,2,3), Quaternion.Euler(0, 30, 0));

The_Unity_Game_Developer · Jan 03, 2015 at 08:21 PM 0

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I forgot to mention, for the spawn points I'm using the public Transform[] spawnPoints; and for the random.range I'm using int indx = Random.Range(0,spawnPoints.Length-1); Vector3 spawnPosition = spawnPoints[indx].position;

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Answer 2

Answer by JeevanjotSingh · Jan 04, 2015 at 04:33 PM

You can take 2 floats and use Random.Range function here is the link

http://unity3d.com/learn/tutorials/modules/beginner/scripting/invoke

this is about invoke but here you can understand about this (how easy to use random.range). Hope i am not wrong .

I am also making my first game so beginner you know but i hope i understand what this error says . It didn't find every parameter properly "PlayerController" is a tag? As you scripted i think you are very well known with unity(or this from a tutorial or a website) but i think you need to watch the instantiate funtion tutorial again . Their you can easily use game object named variable instant of "PlayerController"

Here is the link .

http://unity3d.com/learn/tutorials/modules/beginner/scripting/instantiate

just take you 7 minutes total :)

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How can I Instantiate and do it in a random spot in a random spot?

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