Instantiate Objects using Random? Scripting question...

Unity Engine
1

Hi Everybody,

I am still in the trial period of Unity, but am having so much fun with it I’ll be purchasing it for sure!

I’ve never done any programming before this, so I have a lot of questions about the scripting. So far I’ve been able to get quite a few things happening in my little game I’m making, but have hit a few stumbling blocks I could use help with. I am a professional sound designer, so perhaps if someone has general sound design questions I could be usefull that way and reciprocate if someone can give me a few tips with the scripts.

I have a script to instantiate a sphere every few seconds from an empty game object. The sphere then flys toward the camera. This is working fine, but I would like to make several spheres that get randomly selected, so sometimes sphere 1 comes out, sometimes sphere 2, etc. Also, I would like the timing to vary so its not just every 3 seconds, but between 3-10 seconds. Here is what I am using now:

var newObject: GameObject;

function Start() {
while (true) {
yield WaitForSeconds(3);
Instantiate(newObject, transform.position, transform.rotation);

}
}

I know this is probably simple to do, but I am still trying to get a grasp on programming, so if anyone could give me some tips that would be great.

Thanks!

Matt

2

Arrays to the rescue!

a_spheres = GameObject[]; //array of game objects populated from the Inspector

function Start() {
    var go_selected : GameObject;
    go_selected = a_spheres[Random.Range(0,(a_spheres.length - 1))]; select a random index from the array and pass it to a new var
    while (true) { 
        yield WaitForSeconds(3); 
        Instantiate(go_selected, transform.position, transform.rotation); 
    } 
}
3

Thanks for the reply!

I couldn’t get this code to go, I got this error message from Unity:

“Type ‘System.Type’ does not support slicing.”

Is what you wrote the JavaScript slice Method?

4

The variable needs to be defined correctly. When using Random.Range with integers, the upper range is non-inclusive. Also you’d want to pick a different one every time, not pick a random one and then just instantiate that one always. Should be:

var a_spheres : GameObject[]; //array of game objects populated from the Inspector 

function Start() { 
    while (true) { 
        yield WaitForSeconds(3.0); 
        Instantiate (a_spheres[Random.Range(0, a_spheres.Length)], transform.position, transform.rotation); 
    } 
}

–Eric

5

Thats awesome, its works! Thanks guys, this is really useful.

Matt