CODEWITHSUNDEEP
c#unity-game-engine
Denislav Gavrilov
Denislav Gavrilov

Reputation: 35

How to instantiate 2 objects one after another on the same place

I want to instantiate a prefab before another prefab on the same place chosen randomly by a random number generator in Unity but when I start it, it creates the first prefab on different place. I guess I should change the scope of spawnIndex, but It doesn't allow me to put it on top of everything. Here is my code :

public Transform[] SpawnPoints;
public Transform[] EffectPoints;


public float spawnTime = 1.5f;
public float effectSpawnTime = 1f;

public GameObject Coins;
public GameObject Effect;

int a = Random.Range(0, 4);


// Use this for initialization
void Start()
{

    InvokeRepeating("SpawnParticle", effectSpawnTime, effectSpawnTime);
    InvokeRepeating("SpawnCoins", spawnTime, spawnTime);
}

// Update is called once per frame
void Update()
{

}

void SpawnCoins()
{

    int spawnIndex = Random.Range(0, 4);
    Instantiate(Coins, SpawnPoints[spawnIndex].position, SpawnPoints[spawnIndex].rotation);
}
void SpawnParticle()
{
    int spawnIndex = Random.Range(0, 4);
    Instantiate(Effect, EffectPoints[spawnIndex].position, EffectPoints[spawnIndex].rotation);
}

Upvotes: 0

Views: 521

Answers (1)

Lotan
Lotan

Reputation: 4283

The code you posted have a couple of errors:

  1. First of all, your declaration of int a must be on Start, or awake, but not in the class constructor, or you will get an error, also you don't need 2 variables to accomplish what you want, so I deleted int a and use the same index "spawnIndex" for everything.
  2. Second one, if you want to avoid possible future errors, I suggest you to make the values of the random range an static or at least a variable, don't use "hardcoded", what will happen if you use more than 4 spawn points? -> ERROR
  3. As you say, you are using different random numbers, but you want to use the SAME random number, so every effect and coin will be together. Then use the same variable (you were right, it's an scope problem).

So if we apply all the changes that I mentioned, the result code will be: 

using UnityEngine;

public class Test : MonoBehaviour {

    public Transform[] SpawnPoints;
    public Transform[] EffectPoints;


    public float spawnTime = 1.5f;
    public float effectSpawnTime = 1f;

    public GameObject Coins;
    public GameObject Effect;

    int spawnIndex = 0;
    int maximumRandomRange = 0;
    // Use this for initialization
    void Start()
    {
        //Initialize the variable
        spawnIndex = Random.Range(0, maximumRandomRange);
        maximumRandomRange = SpawnPoints.Length; //or EffectPoints.Length, as they got the same

        InvokeRepeating("SpawnParticle", effectSpawnTime, effectSpawnTime);
        InvokeRepeating("SpawnCoins", spawnTime, spawnTime);
    }

    void SpawnCoins()
    {
        Instantiate(Coins, SpawnPoints[spawnIndex].position, SpawnPoints[spawnIndex].rotation);
    }
    void SpawnParticle()
    {
        spawnIndex = Random.Range(0, maximumRandomRange); //You only need to call it here again, as it is the function which is called faster
        Instantiate(Effect, EffectPoints[spawnIndex].position, EffectPoints[spawnIndex].rotation);
    }

}

Upvotes: 4

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