TrackingManager.cs

using System;
using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.UI;
using UnityEngine.XR;
using UnityEngine.XR.ARFoundation;
using UnityEngine.Events;

[RequireComponent(typeof(ARTrackedImageManager))]
public class TrackingManager : MonoBehaviour
{
    [SerializeField]
    private GameObject welcomePanel;

    // [SerializeField]
    // private Button dismissButton;

    [SerializeField]
    private GameObject[] arObjectsToPlace;

    // [SerializeField]
    // private Text imageTrackedText;

    [SerializeField] private Vector3 scaleFactor = new Vector3(0.1f, 0.1f, 0.1f);
    
    private ARTrackedImageManager m_TrackedImageManager;

    private Dictionary<string, GameObject> arObjects = new Dictionary<string, GameObject>();

    void Awake()
    {
        // dismissButton.onClick.AddListener(Dismiss);
        m_TrackedImageManager = GetComponent<ARTrackedImageManager>();
        

        foreach (GameObject arObject in arObjectsToPlace)
        {
            // GameObject newARObj = Instantiate(arObject, Vector3.zero, Quaternion.identity);
            arObject.SetActive(true);
            arObject.name = arObject.name;
            arObjects.Add(arObject.name, arObject);
        }
    }

    void OnEnable()
    {
        m_TrackedImageManager.trackedImagesChanged += OnTrackedImagesChanged;
    }

    void OnDisable()
    {
        m_TrackedImageManager.trackedImagesChanged -= OnTrackedImagesChanged;
    }

    private void Dismiss() => welcomePanel.SetActive(false);
    

    void OnTrackedImagesChanged(ARTrackedImagesChangedEventArgs eventArgs)
    {
        foreach (ARTrackedImage trackedImage in eventArgs.added)
        {
            // Give the initial image a reasonable default scale
            // trackedImage.transform.localScale = 
            //     new Vector3(-trackedImage.referenceImage.size.x, 0.005f, -trackedImage.referenceImage.size.y);
            
            UpdateARImage(trackedImage);
        }

        foreach (ARTrackedImage trackedImage in eventArgs.updated)
        {
            // Give the initial image a reasonable default scale
            // trackedImage.transform.localScale = 
            //     new Vector3(-trackedImage.referenceImage.size.x, 0.005f, -trackedImage.referenceImage.size.y);
            
            UpdateARImage(trackedImage);
        }

        foreach (ARTrackedImage trackedImage in eventArgs.removed)
        {
            arObjects[trackedImage.name].SetActive(false);
        }
    }

    void UpdateARImage(ARTrackedImage trackedImage)
    {
        AssignGameObject(trackedImage.referenceImage.name, trackedImage.transform.position, trackedImage.transform.rotation);
    }

    void AssignGameObject(string name, Vector3 newPosition, Quaternion newRotation)
    {
        if (arObjectsToPlace != null)
        {
            GameObject goARObj = arObjects[name];
            goARObj.SetActive(true);
            goARObj.transform.position = newPosition;
            goARObj.transform.rotation = newRotation;
            goARObj.transform.localScale = scaleFactor;
            foreach (GameObject go in arObjects.Values)
            {
                if (go.name != name)
                {
                    go.SetActive(false);
                }
            }
        }
    }
}