Unity and Vuforia: Target Image ID and GUI Windows

Question

I'm using Unity and Vuforia to make a secret project for my tabletop RPG group. Right now I'm running into an issue of lack of references and removed web pages on Vuforia's site.

Currently, my issue is this: I want to track up to 5 target images and, when scanned, have each of them to create their own individual GUI Window that tracks with the image in the UI. I have part of it working, I can track all the images, but only 1 window appears at a time. I know the actual images work because I have placeholder 3d objects included for debugging.

The script I used for the base for the GUI Windows: https://developer.vuforia.com/forum/faq/unity-how-can-i-popup-gui-button-when-target-detected

I think my problem lies in the OnTrackableStateChanged() (Lines 19-32 link; 28-43 my code below). I need to alter it so it can take into account multiple target images. Then again I could be SUPER wrong because any references on Vuforia's API site or forums has been removed. Does anyone have a possible idea on what I can do to accomplish my goal? I'm currently thinking using the getID() function and then, somehow, having OnTrackableStateChange() check if the changed ID was different than the original idea. But again, I could be overlooking a simpler solution.

If this isn't clear I can try to be elaborate a bit more. Below is the code I'm using that uses components from the link above. Thank you for the help. :

using UnityEngine;
using System.Collections;

public class ButtonPopup : MonoBehaviour, Vuforia.ITrackableEventHandler
{

    private Vuforia.TrackableBehaviour mTrackableBehaviour;

    private bool mShowGUIWindow = false;
    private TargetScreenCoords coordinateScript;
    public int ID;
    private Rect mWindowRect;
    public string Name;
    public int Health;
    public string Status;
    public bool Villain;


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

    public void OnTrackableStateChanged(
                                    Vuforia.TrackableBehaviour.Status previousStatus,
                                    Vuforia.TrackableBehaviour.Status newStatus)
    {

        if (newStatus == Vuforia.TrackableBehaviour.Status.DETECTED ||
            newStatus == Vuforia.TrackableBehaviour.Status.TRACKED)
        {
            mShowGUIWindow = true;
        }
        else
        {
            mShowGUIWindow = false;

        }
    }

    void OnGUI()
    {
        coordinateScript = GetComponent<TargetScreenCoords>();
        mWindowRect = new Rect(coordinateScript.screenPoint.x, Mathf.Abs(coordinateScript.screenPoint.y), 120, 100);

        if (Villain == true)
        {
            GUI.backgroundColor = Color.red;
        }
        if (Villain == false)
        {
            GUI.backgroundColor = Color.green;
        }
        if (mShowGUIWindow)
        {
            mWindowRect = GUI.Window(ID, mWindowRect, DoMyWindow, "ID:" + ID);
        }
    }

    void DoMyWindow(int windowID)
    {
        GUI.Label(new Rect(10, 20, 100, 60), new GUIContent("Name: " + Name + "\nHealth: " + Health + "\nStatus: " + Status));
        if (GUI.Button(new Rect(10, 70, 100, 20), "Edit Button"))
        {
            print("Got a click");
            Villain = !Villain;
        }

    }
}

Thanks again for the help/ideas.

Have you tried using MultiTarget prefab instead of ImageTargets? — Kasia Lukosek
MultiTarget specifically looks for orientation. So if 2 images are together it does a thing, or if they are so far apart do another thing. I don't want that (yet) in my project. — Travis

Adam Macierzyński Adam Macierzyński · Accepted Answer · 2017-02-16T11:42:17

The first question is, if you want to track those 5 targets simultaneously? If yes, remember that you need to specify it in the ARCamera configuration. Set Max Simultaneous Tracked Images to 5 under the ARCamer object in scene.

Under each ImageTarget you should also have a Trackable Event Handler script. By default it is DefaultTrackableEventHandler. In this script you have 2 private methods OnTrackingFound() and OnTrackingLost(). Try to add there 3rd foreach loop where you will enable/disable your GUI object type (Canvas or something like that).

Unity and Vuforia: Target Image ID and GUI Windows

1 Answers