CODEWITHSUNDEEP
c#unity-game-enginenullinstance
Prof
Prof

Reputation: 101

Instantiating prefabs from another script (The prefab you want to instantiate is null)

So I have an enemy spawner with a method to instantiate prefabs working just fine. Simplified:

public class EnemySpawner : MonoBehaviour {

public GameObject EnemyPrefab;

public void setEnemies()
{
    Instantiate (EnemyPrefab, enemyPos, rotation);
}

void Start()
{
    setEnemies();
}

}

This works fine. But it doesnt work when I call it from a different script:

public class Player : MonoBehaviour {
public EnemySpawner enemyspawner;

void Update(){
   if (Input.GetMouseButtonDown (0)) 
   {
      enemyspawner= new EnemySpawner();
       enemyspawner.setEnemies();
   }
}

I keep getting this error:

ArgumentException: The prefab you want to instantiate is null.

What am I doing wrong?

Edit: So I figured that I could not create a Monobeaviour by using the New keyword .I changed it to: 

enemyspawner = gameObject.AddComponent<EnemySpawner> ();

enemyspawner.setEnemies();

But that still wont work.

Upvotes: 0

Views: 1989

Answers (1)

axwcode
axwcode

Reputation: 7824

I just read your comment about changing:

new to enemyspawner = gameObject.AddComponent<EnemySpawner>();

However, you did not properly solve the problem, you only made a workaround that won't work because your prefab, public GameObject EnemyPrefab;, won't be set.

With your new code gameObject.AddComponent<EnemySpawner>(); You are attaching a script to the Player GameObject, this will bring you problems in the future.

My Suggestion

Create an Empty GameObject and attach EnemySpawner to it and name it EnemySpawnerObj.

Then to call the function setEnemies() from another class you do this:

EnemySpawner spwner = GameObject.Find("EnemySpawnerObject").GetComponent<EnemySpawner>();
spwner.setEnemies();

So what you are doing is looking through your scene for the GameObject named EnemySpawnerObject then you get the component named EnemySpawner and then you can call that class instance.

Upvotes: 1

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