Bug Image TrackingState stay in TrackingState.Tracking even if the image is no longer visible

Good evening, I am writing because I think I have found a bug which consists in the fact that the traking state of an trakingimage, in certain circumstances, remains in traking even if the image is no longer visible.

I recreated the problem using a video. I used the AR foundation sample and made some minor tweaks to make the problem more evident.

Code (CSharp):

1. void UpdateInfo(ARTrackedImage trackedImage)
2.         {
3.             // Set canvas camera
4.             var canvas = trackedImage.GetComponentInChildren<Canvas>();
5.             canvas.worldCamera = worldSpaceCanvasCamera;
6.        
7.             //CHANGE
8.             canvas.enabled = true;
9.             // Update information about the tracked image
10.             var text = canvas.GetComponentInChildren<Text>();
11.             text.text = string.Format(
12.                 "{0}\ntrackingState: {1}\nGUID: {2}\nReference size: {3} cm\nDetected size: {4} cm",
13.                 trackedImage.referenceImage.name,
14.                 trackedImage.trackingState,
15.                 trackedImage.referenceImage.guid,
16.                 trackedImage.referenceImage.size * 100f,
17.                 trackedImage.size * 100f);
18.             var planeParentGo = trackedImage.transform.GetChild(0).gameObject;
19.             var planeGo = planeParentGo.transform.GetChild(0).gameObject;
20.             // CHANGE
21.             if (trackedImage.trackingState == TrackingState.Tracking)
22.             {
23.                 planeGo.SetActive(true);
24.                 // The image extents is only valid when the image is being tracked
25.                 trackedImage.transform.localScale = new Vector3(trackedImage.size.x, 1f, trackedImage.size.y);
26.                 // Set the texture
27.                 var material = planeGo.GetComponentInChildren<MeshRenderer>().material;
28.                 material.mainTexture = (trackedImage.referenceImage.texture == null) ? defaultTexture : trackedImage.referenceImage.texture;
29.             }
30.             else
31.             {
32.                 planeGo.SetActive(false);
33.                 canvas.enabled = false;
34.             }
35.         }

As shown in the video, when I frame an image and switch to the next one, for some reason the traking state of the first image remains in traking when it should go into limited since the image is no longer visible.

This problem occurs when two images of the same size overlap quickly.

 

https://forum.unity.com/threads/xrt...-trackingstate-tracking.1290950/#post-8193831

 

OK! I got it. Is there any way around this? Because I don't know how to do it, since the traking state is the only thing I use to determine whether an image is visible or not.

 

Thank you, that is what i needed.