Blackthornprod's random dungeon tutorial, NullReferenceException problem.

Unity Engine
,
1

As the title says I’m having a problem with ‘NullReferenceException: Object reference not set to an instance of an object’ when putting in the code for the tutorial.
It says that the lines with the problem are: 34, 39, 44, 49

using System.Collections;
using System.Collections.Generic;
using System.Security.Cryptography;
using UnityEngine;

public class RoomSpawner : MonoBehaviour
{
    public int openingDirection;
    // 1 --> need bottom door
    // 2 --> need top door
    // 3 --> need left door
    // 4 --> need right door

    public RoomTemplates templates;
    private int rand;
    private bool spawned = false;

    public float waitTime = 4f;

    void Start()
    {
        Destroy(gameObject, waitTime);
        templates = GameObject.FindGameObjectWithTag("Rooms").GetComponent<RoomTemplates>();
        Invoke("Spawn", 0.5f);
    }

    void Spawn()
    {
        if (spawned == false)
        {

            if (openingDirection == 1)
            {
                rand = Random.Range(0, templates.bottomRooms.Length);
                Instantiate(templates.bottomRooms[rand], transform.position, templates.bottomRooms[rand].transform.rotation);
            }
            else if (openingDirection == 2)
            {
                rand = Random.Range(0, templates.topRooms.Length);
                Instantiate(templates.topRooms[rand], transform.position, templates.topRooms[rand].transform.rotation);
            }
            else if (openingDirection == 3)
            {
                rand = Random.Range(0, templates.leftRooms.Length);
                Instantiate(templates.leftRooms[rand], transform.position, templates.leftRooms[rand].transform.rotation);
            }
            else if (openingDirection == 4)
            {
                rand = Random.Range(0, templates.rightRooms.Length);
                Instantiate(templates.rightRooms[rand], transform.position, templates.rightRooms[rand].transform.rotation);
            }
            spawned = true;
        }
    }

    void OnTriggerEnter2D(Collider2D other)
    {
        if (other.CompareTag("SpawnPoint"))
        {
            if(other.GetComponent<RoomSpawner>().spawned == false && spawned == false)
            {
                Instantiate(templates.closedRooms, transform.position, Quaternion.identity);              
                Destroy(gameObject);
            }
            spawned = true;
        }
    }
}

Any help would be greatly appreciated!

2

Put a debug.log check if templates been assigned. If it is check all the templates.xxxxroom see is all of them is null

3

Where should I put debug.log? (Sorry I’m new to this kind of stuff lol)

4

Can put on start of spwan

If(templaes == null)
{
    Debug.Log("templates not been set");
}

If this been trigger and display and the console log then this haven’t found the object you were hoping for

templates = GameObject.FindGameObjectWithTag("Rooms").GetComponent<RoomTemplates>();

And can do a debug.log for all the templates.xxxxroom

5

oooh ok thank you! I’ll try that. And if the ‘Templates’ aren’t null? How do I set that?

6

If is null . Why don’t you just drag it in from editor since your templates is public

7

If isn’t null make sure the object with the tag rooms have the script RoomTemplates

8

omg thank you so much! I finally found out that I put the script to the wrong Game Object. You’re a life saver, I hope you have a great day

1 Like
9

I still have this issue except only on line 62. I have the script on the correct gameobject and everything, I would love some help.