OnTriggerEnter Null Object Reference

Unity Engine
,
1

So I was making an object pickup script for VR, and I was almost done patching all possible bugs it had.
I was adding a new handler for this bug where if my right controller was holding an object, and I put my left controller into it, it would drop it’s object. I just finished the script and decided to test it out. The right controller worked, but when my left controller collided with an object, I got this error:

Object reference not set to an instance of an object Pickup.OnTriggerEnter (UnityEngine.Collider other)

And this was an internal error it seems. Takes place at line 46:

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class Pickup : MonoBehaviour
{
    public bool canHold;
    public bool isHolding;
    public GameObject PickableObject;
    public Pickup Left;
    public Pickup Right;
    public bool isLeft;

    public void Down()
    {
        if (canHold == true)
        {
            if (PickableObject != null)
            {
                if (isHolding == false)
                {
                    isHolding = true;
                }
                else if (isHolding == true)
                {
                    isHolding = false;
                }
            }
        }
    }

    void Start()
    {
        if (gameObject.name == "XRControllerLeft")
        {
            isLeft = true;
        }
    }

    public void OnTriggerEnter(Collider other)
    {
        if (PickableObject == null)
        {
            if (isLeft == true)
            {
                if (other.gameObject != Right.PickableObject)
                {
                    if (isHolding != true)
                    {
                        if (other.gameObject.GetComponent<PickableObjectData>())
                        {
                            canHold = true;
                            PickableObject = other.gameObject;
                        }
                    }
                }
            }
            else if (isLeft == false)
            {
                if (other.gameObject != Left.PickableObject)
                {
                    if (isHolding != true)
                    {
                        if (other.gameObject.GetComponent<PickableObjectData>())
                        {
                            canHold = true;
                            PickableObject = other.gameObject;
                        }
                    }
                }
            }
        }
    }
    public void OnTriggerExit(Collider other)
    {
        if (isHolding != true)
        {
            canHold = false;
            PickableObject = null;
        }
    }
    void Update()
    {
        if (PickableObject != null)
        {
            if (isLeft == true)
            {
                if (isHolding == true)
                {
                    PickableObject.transform.parent = transform;
                    PickableObject.GetComponent<Rigidbody>().isKinematic = true;
                }
                else if (isHolding == false)
                {
                    PickableObject.transform.parent = null;
                    PickableObject.GetComponent<Rigidbody>().isKinematic = false;
                }
            }
            else if (isLeft == false)
            {
                if (PickableObject != Left.PickableObject)
                {
                    if (isHolding == true)
                    {
                        PickableObject.transform.parent = transform;
                        PickableObject.GetComponent<Rigidbody>().isKinematic = true;
                    }
                    else if (isHolding == false)
                    {
                        PickableObject.transform.parent = null;
                        PickableObject.GetComponent<Rigidbody>().isKinematic = false;
                    }
                }
            }
        }
    }
}

Any advice on other things in this code is much appreciated.
Thanks in advance.

Edit: I fixed it because Right wasn’t assigned in the inspector, but for some reason it was saying that Collider other wasn’t defined.

2

This is just a null ref error.

  1. Find out what is null
  2. Find out why it’s null
  3. Fix it.

So, looking at line 46, my guess is Right is null.

1 Like
3

But how does it trigger without that being defined?

4

Well nothing assigns Right in your code, so it’s most likely you never assigned it in the inspector?

It’s just a simple null ref. Figure out what is null, stop it being null.

1 Like
5

I assigned it in the inspector. Everything that should be assigned is assigned.

Edit: I thought Right was assigned in the inspector.

6

I fixed it because Right wasn’t assigned in the inspector, but for some reason it was saying that Collider other wasn’t defined.

7

No it wasn’t, it was just telling you there was a null ref on a particular line. And because ‘nothing’ can’t cause a collision, there was only one possibility: that Right was null.

1 Like