[SOLVED] Compass Bar Not Working

Unity Engine
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1

Hey, I was following a tutorial on YouTube, and I followed the tutorial word for word, and I keep getting the same error.

NullReferenceException: Object reference not set to an instance of an object
CompassBar.SetMarkerPosition (UnityEngine.RectTransform markerTransform, UnityEngine.Vector3 worldPosition) (at Assets/Scripts/Util/CompassBar.cs:74)
CompassBar.Update () (at Assets/Scripts/Util/CompassBar.cs:32)

here is the script.

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

public class CompassBar : MonoBehaviour
{
    public RectTransform compassBarTransform;

    public RectTransform objectiveMarkerTransform;
    public RectTransform northMarkerTransform;
    public RectTransform southMarkerTransform;

    public Transform cameraObjectTransform;
    public Transform objectiveObjectTransform;

    void Update()
    {
        Debug.Log("Update method called.");

        // Add detailed null checks and debug logs before calling SetMarkerPosition
        if (objectiveMarkerTransform == null)
        {
            Debug.LogError("objectiveMarkerTransform is not assigned!");
        }
        else if (objectiveObjectTransform == null)
        {
            Debug.LogError("objectiveObjectTransform is not assigned!");
        }
        else
        {
            SetMarkerPosition(objectiveMarkerTransform, objectiveObjectTransform.position);
        }

        if (northMarkerTransform == null)
        {
            Debug.LogError("northMarkerTransform is not assigned!");
        }
        else
        {
            SetMarkerPosition(northMarkerTransform, Vector3.forward * 1000);
        }

        if (southMarkerTransform == null)
        {
            Debug.LogError("southMarkerTransform is not assigned!");
        }
        else
        {
            SetMarkerPosition(southMarkerTransform, Vector3.back * 1000);
        }
    }

    private void SetMarkerPosition(RectTransform markerTransform, Vector3 worldPosition)
    {
        if (markerTransform == null)
        {
            Debug.LogError("Marker Transform is not assigned!");
            return;
        }
        if (cameraObjectTransform == null)
        {
            Debug.LogError("Camera Object Transform is not assigned!");
            return;
        }
        if (compassBarTransform == null)
        {
            Debug.LogError("Compass Bar Transform is not assigned!");
            return;
        }

        Vector3 directionToTarget = worldPosition - cameraObjectTransform.position;
        float angle = Vector2.Angle(new Vector2(directionToTarget.x, directionToTarget.z), new Vector2(cameraObjectTransform.transform.forward.x, cameraObjectTransform.transform.forward.z));
        float compassPositionX = Mathf.Clamp(2 * angle / Camera.main.fieldOfView, -1, 1);
        markerTransform.anchoredPosition = new Vector2(compassBarTransform.rect.width / 2 * compassPositionX, 0);

        Debug.Log($"SetMarkerPosition called for {markerTransform.name} with position {worldPosition}");
    }
}
2

Look at the line number (74) and see what the method is trying to do:
CompassBar.SetMarkerPosition (UnityEngine.RectTransform markerTransform, UnityEngine.Vector3 worldPosition)
The other line number (32) calls the method and passes in a transform and a Vector3. My guess is that the transform hasn’t been assigned in the Inspector. Though I don’t know why the null check doesn’t catch it.

3

Looking at line 74 it could be that Camera.main is null. This usually happens when there is no camera tagged “Main Camera” in any loaded scene.

Perhaps reference the desired camera directly instead.

Of course do some testing to check if it is the null culprit, first. Need to first find out what is null before you can fix it.

4

thank you so much