The problem is that the camera olny augments the 3d model when it is tracking the image target. I have tried using extended tracking feature but still the 3D image disappears when the camera is not tracking the image target. Is there a way I can allow the 3d model to be pined on a certain location afeter the image target is tracked?

I tried using the script below and it’s giving me the following error message: The type or namespace name ‘ITrackableEventHandler’ could not be found(are you missing a using directive or an assembly reference?

using UnityEngine;
using Vuforia;

public class KeepObjectVisible : MonoBehaviour, ITrackableEventHandler
{
    private TrackableBehaviour mTrackableBehaviour;
    private bool isTracking = false;

    void Start()
    {
        mTrackableBehaviour = GetComponent<TrackableBehaviour>();
        if (mTrackableBehaviour)
        {
            mTrackableBehaviour.RegisterTrackableEventHandler(this);
        }
    }

    public void OnTrackableStateChanged(
        TrackableBehaviour.Status previousStatus,
        TrackableBehaviour.Status newStatus)
    {
        if (newStatus == TrackableBehaviour.Status.DETECTED ||
            newStatus == TrackableBehaviour.Status.TRACKED ||
            newStatus == TrackableBehaviour.Status.EXTENDED_TRACKED)
        {
            OnTrackingFound();
        }
        else if (previousStatus == TrackableBehaviour.Status.TRACKED &&
                 newStatus == TrackableBehaviour.Status.NO_POSE)
        {
            OnTrackingLost();
        }
        else
        {
            OnTrackingLost();
        }
    }

    private void OnTrackingFound()
    {
        isTracking = true;
        SetChildrenActive(true);
    }

    private void OnTrackingLost()
    {
        isTracking = false;
        // Here, we do not deactivate the children to keep the object visible.
    }

    void Update()
    {
        if (!isTracking)
        {
            // Logic to keep the object visible and possibly maintain its last known position.
        }
    }

    private void SetChildrenActive(bool active)
    {
        foreach (Transform child in transform)
        {
            child.gameObject.SetActive(active);
        }
    }
}