Beginner B05 – Instantiate to Create Objects
How to create objects in your scene during runtime using Prefabs and the Instantiate() command.
Code Used
//Simple Instantiation of a Prefab at Start
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var thePrefab : GameObject;
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function Start () {
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var instance : GameObject = Instantiate(thePrefab, transform.position, transform.rotation);
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}
Related Modules & Challenges
Further Reading
23 Comments
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I used the following script:
var thePrefab : gameObject;
function Update () {
if(Input.GetButtonUp(“Jump”)){
var instance : gameObject = Instantiate(ThePrefab, transform.position, transform.rotation);
}
}
I got the following error:
BCE0018: The name ‘gameObject’ does not denote a valid type. Did you mean ‘UnityEngine.GameObject’?
u must type GameObject, not gameObject
you need a big G in Gameobject, thats your problem.
and you are missing a big O in your GameObject.
I tried to instantiate an object when I pressed space, but it instantiated the object every frame I had the space button pressed in, so I used this script (se below) to make it only instantiate it one time, is there a bether way to make it only instantiate it one time?
//Simple Instantiation of a Prefab when a button is pressed
var thePrefab : GameObject;
var ObjectLimit = 1;
var InstantiatedObjects = 0;
function Update () {
if (Input.GetButton(“Jump”)) {
//Check if the prefab already has been instantiated
if (InstantiatedObjects < ObjectLimit) {
var instance : GameObject = Instantiate(thePrefab, transform.position, transform.rotation);
InstantiatedObjects ++;
}
}
}
Simen, I think using GetButtonUp instead of GetButton might fix your problem. I think using just GetButton means it’ll check if the key or button is currently being pressed every frame and carry out whatever you set it to do. If you use GetButtonUp, it still checks every frame but it checks if the key/button has been both pressed and released so only executes whatever you told it to do (in this case instanciate an object) once until you press the key again instead of once each frame..
Couldn’t have put it better myself! Excellent stuff Aaron!
Thanks a lot aaron:)
Hi everyone, I kept the objectLimit++ incrementing variable outside the if statement, else it would’nt work..
var Box2 : GameObject;
public var objectLimit : int = 0;
public var objectadd : int = 5;
function Update () {
if(Input.GetButtonUp(“Jump”)){
var instaceBox2 : GameObject = Instantiate(Box2, transform.position,transform.rotation);
if(objectLimit > objectadd){
Destroy(gameObject.Find(“Wall”));
}
objectLimit++;
}
}
Hi,
I am trying to find a property of the instantiated objects to find them with. Suppose i make a prefab named bullet and i shoot(Instantiate) some it in the game. Later i want to find them again, a guy comes by with a big magnet or something
How can i query for a instantiated object of the prefab bullet? What i do know is search for “bullet(Clone)” it works but it isn’t very clean.
Regards,
Deg
Hi Deg
well if you want to address something you’ve just created you’ll create a variable for the instantiation, like this -
var thingToMake : GameObject = Instantiate(prefab, transform.position, transform.rotation);
then you can do what you like to that variable and it’ll address the recently made instance of the prefab -
thingToMake.name = “bullet”;
the above would name it so that it won’t be named like the prefab with ‘(Clone)’ on the end. Alternatively if you’re firing differently named objects you could tag them with a particular tag, and then find objects with that name.
Moving on from that you could add the bullet to an array but I’m not too sure why you’d really need to do something like that for a bullet.
It is more in general really, i try to avoid globals as much as possible. So when I, at point A in the game, instantiate prefabs in the game without storing any references to them. Can I, at point C in the game, find them again? I guess I got spoiled by collection based programming such as python & jquery. There is a lot of caching going on in the background there though, it is probably better to store references right away in unity.
Anyway the tagging is something I can dive into together with some reading up on globals handling in unity.
cheers,
Deg
I try to do the same in C# but it’s not working
Someone can do this in C#?
Can you post what you have to http://www.pasteit4me.com, and then post the link back here in the comments and we’ll do our best to tell you what you have done wrong.
Here is the C# code…
using UnityEngine;
using System.Collections;
public class Creator : MonoBehaviour {
public GameObject thePrefab; //Needs to be declared as public to be seen in editor
// Use this for initialization
void Start () {
GameObject instance = new GameObject();
instance = Instantiate(thePrefab, transform.position, transform.rotation) as GameObject;
}
}
This was just what I was looking for, I struggled with this for a while.
Now I can finally instantiate my bullets how I want to!
Ow, the “GameObject instance = new GameObject();” part creates empty gameobjects for me. I changed it to:
GameObject instance = Instantiate(thePrefab, transform.position, transform.rotation) as GameObject;
And now it works fine.
Hi Will,
This is the father of the Bob Berkebile (Pixelplacement) that you know. I’m working with my son and trying to learn this stuff.
These are excellent training videos, easy to follow, easy to understand. One thing that would help me personally is if you could also provide the code in C# in addition to Javascript.
Anyway, thanks again.
Hi there Mr B, great to hear from you. Providing the C# equivalent is something I’ve always meant to do but kept putting on the backburner in favour of ideas for new content – but for you I’ll put it on the new years resolution list to get done as swiftly as possible. I certainly owe you for making such a productive progeny in the realms of highly useful Unity freebies!
I’m a little confused with variables. I thought a var was just for storing values, but here the var line seems to be taking action and instantiating the object.
I also tested that by re-defining the variable, it would create another copy of the prefab. (instance = Instantiate(thePrefab, transform.position+Vector3(10,10,10),transform.rotation);)
What exactly is happening here? Which part actually says “Make a new object”?
… Instantiate(thePrefab, transform.position, transform.rotation)
This function says make a new object based on “thePrefab” located at the position of the GameObject the script is attached to (transform.position) and rotated to match the alignment of the GameObject the script is attached to (transform.rotation).
var instance : GameObject = …
The function also returns a reference to the newly created GameObject so that is why it is assigned to instance which just so happens to be declared on the same line.
this is what I did.
var thePrefab : Transform; // so I can access it and link an object.
function Start() {
instance = Instantiate(thePrefab,transform.position, transform.rotation);
instance.name=”Somename”;
}
and in c#
using UnityEngine;
using System.Collections;
public class CreatorCS : MonoBehaviour {
public Transform thePrefab;
void Start () {
Instantiate(thePrefab, transform.position, transform.rotation);
}
}
Hi everyone, I have a couple of bouncy cubes inside 4 walls. I am trying to instantiate a cube each time any of the cubes do bounce against any of the walls. Here’s my code:
var thePrefab : GameObject;
function OnCollisionEnter(theCollision : Collision) {
if (theCollision.gameObject.name == “Wall”)
{
var instance : GameObject = Instantiate (thePrefab, transform.position, transform.rotation);
}
}
Problem is, it is not instantiating, is there some error within my code? Thank you!
P.S. Console does not give me any errors.