# How to Locate Vuforia Datasets in StreamingAssets on ML2?

**URL:** <https://forum.magicleap.cloud/t/how-to-locate-vuforia-datasets-in-streamingassets-on-ml2/2357>\
**Category:** Vuforia Engine\
**Created:** [August 10, 2023, 8:44pm UTC](https://forum.magicleap.cloud/t/how-to-locate-vuforia-datasets-in-streamingassets-on-ml2/2357 "2023-08-10T20:44:56Z")\
**Posts on this page:** 8\
**Page:** 1

<div class="post-metadata">

**Author:** ![zhhqu0305](https://avatars.discourse-cdn.com/v4/letter/z/a9a28c/32.png) [@zhhqu0305](https://forum.magicleap.cloud/u/zhhqu0305)\
**Post date:** [August 10, 2023, 8:44pm UTC](https://forum.magicleap.cloud/t/how-to-locate-vuforia-datasets-in-streamingassets-on-ml2/2357/1 "2023-08-10T20:44:56Z")

</div>

I'm using Vuforia for ImageTargets tracking and I need to create the ImageTargets at runtime. I followed [Create and Load Targets in Unity | Vuforia Library](https://library.vuforia.com/unity-extension/create-and-load-targets-unity#create-multiple-targets-from-a-device-database-at-runtime) for async creation of targets after initializing, but on ML2 I got the following log message (I'm using `$"{Application.streamingAssetsPath}/Vuforia/My_Device_Database.xml"` for the path to my xml file):

```auto
Error;AR;Failed to load database 'jar:file:///data/app/com.UnityTechnologies.com.unity.template.urpblank-q_RAA3amkxCDElED5Zou6w==/base.apk!/assets/Vuforia/Sudoku.xml'.;

```

Also here's the screenshot of ML Hub Logs:

 ![P7UP}S1L7V66$T5W7@ED1`8](https://us1.discourse-cdn.com/flex019/uploads/magicleap1/original/2X/5/5998d545602fe39672f89b0865372fb738bef091.png)

Any help would be appreciated!

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<div class="post-metadata">

**Author:** ![emichals](https://avatars.discourse-cdn.com/v4/letter/e/50afbb/32.png) [@emichals](https://forum.magicleap.cloud/u/emichals)\
**Post date:** [August 17, 2023, 12:54pm UTC](https://forum.magicleap.cloud/t/how-to-locate-vuforia-datasets-in-streamingassets-on-ml2/2357/2 "2023-08-17T12:54:14Z")

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Hi,

For runtime Image Targets, you can create them from the image file and get the pointer:

`var imageTarget = VuforiaBehaviour.Instance.ObserverFactory.CreateImageTarget( textureFile, printedTargetSize, targetName);`

The alternative is to have the Image Targets in a database and load them at runtime to "create them", which is outlined in the top section of the article: [Create an Image Target from a Device Database at Runtime](https://library.vuforia.com/unity-extension/create-and-load-targets-unity#create-an-image-target-from-a-device-database-at-runtime)

Hope that helps

---

<div class="post-metadata">

**Author:** ![zhhqu0305](https://avatars.discourse-cdn.com/v4/letter/z/a9a28c/32.png) [@zhhqu0305](https://forum.magicleap.cloud/u/zhhqu0305)\
**Post date:** [August 17, 2023, 2:58pm UTC](https://forum.magicleap.cloud/t/how-to-locate-vuforia-datasets-in-streamingassets-on-ml2/2357/3 "2023-08-17T14:58:45Z")

</div>

Hi @emichals,

Thanks for your reply. For creating the objects, I'm using the following code:

```auto
using UnityEngine;
using Vuforia;

public class AsyncTargetLoading : MonoBehaviour
{
    static readonly string[] targetNames = new[] { "hard_1417", "hard_1418" };
    private string databasePath = $"{Application.streamingAssetsPath}/Vuforia/Sudoku.xml";

    void Start()
    {
        VuforiaApplication.Instance.OnVuforiaInitialized += OnVuforiaInitialized;
    }

    void OnVuforiaInitialized(VuforiaInitError error)
    {
        if (error == VuforiaInitError.NONE)
        {
            CreateIT();
        }
    }
    // Start is called before the first frame update
    public async void CreateIT()
    {

        // Create an Image Target for each target name in dataset
        foreach (var target in targetNames)
        {
            var itBehaviour = await VuforiaBehaviour.Instance.ObserverFactory.CreateImageTargetAsync(databasePath, target);

            itBehaviour.tag = "KeyTarget";
            Debug.Log("target created: " + target);
            GameObject createdObject = itBehaviour.gameObject;

            createdObject.AddComponent<MyPrefabInstantiator>();

            // itBehaviour.OnTargetStatusChanged += OnTargetStatusChanged;
            AllVariables.Instance.allImageTargets.Add(itBehaviour);

        }
    }

    void OnTargetStatusChanged(ObserverBehaviour behaviour, TargetStatus status)
    {
        Debug.Log($"target status: {behaviour.TargetName} {status.Status} {status.StatusInfo}");
    }
}

```

I believe this follows your async example? The problem I have is that this .xml file seems to fail to load due to unknown issues only on ML2 (I can do it successfully in play mode). My .xml file is located at `StreamingAssets/Vuforia/Sudoku.xml`, which looks like:

```auto
<?xml version="1.0" encoding="UTF-8"?>
<QCARConfig>
  <Tracking>
    <ImageTarget name="hard_1418" size="0.128000 0.128000" />
    <ImageTarget name="hard_1417" size="0.113000 0.113000" />
  </Tracking>
</QCARConfig>

```

In the Vuforia Sample for ML2 I found the imageTargets to be created not during runtime and thus cannot find any working example. Have you observed similar problems?

Thanks in advance!

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<div class="post-metadata">

**Author:** ![emichals](https://avatars.discourse-cdn.com/v4/letter/e/50afbb/32.png) [@emichals](https://forum.magicleap.cloud/u/emichals)\
**Post date:** [August 18, 2023, 2:51pm UTC](https://forum.magicleap.cloud/t/how-to-locate-vuforia-datasets-in-streamingassets-on-ml2/2357/4 "2023-08-18T14:51:13Z")

</div>

Hi,

A couple things to check... is the xml file actually being copied into the APK? Perhaps there's a configuration somewhere set incorrectly so it's not being copied there. ie, verify the file is indeed where it's expected to be.

You could also check for the file in your script, before calling the `CreateImageTargetAsync` function, and verify it can at least be accessed by your script. In other words, confirm the file can be accessed at all, and that it's not just the `CreateImageTargetAsync` function that's having issues.

Also, could you try loading the database from just `Vuforia/dataset.xml`? Wondering if the `jar:file://...` is causing some sort of issue?

Hope that helps

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<div class="post-metadata">

**Author:** ![zhhqu0305](https://avatars.discourse-cdn.com/v4/letter/z/a9a28c/32.png) [@zhhqu0305](https://forum.magicleap.cloud/u/zhhqu0305)\
**Post date:** [August 18, 2023, 4:19pm UTC](https://forum.magicleap.cloud/t/how-to-locate-vuforia-datasets-in-streamingassets-on-ml2/2357/5 "2023-08-18T16:19:12Z")

</div>

Thanks for your reply. May I ask how can I check whether the file is copied into the APK? Also do you mean I should try to not use `{Application.streamingAssetsPath}` as the prefix?

---

<div class="post-metadata">

**Author:** ![emichals](https://avatars.discourse-cdn.com/v4/letter/e/50afbb/32.png) [@emichals](https://forum.magicleap.cloud/u/emichals)\
**Post date:** [August 18, 2023, 5:50pm UTC](https://forum.magicleap.cloud/t/how-to-locate-vuforia-datasets-in-streamingassets-on-ml2/2357/6 "2023-08-18T17:50:28Z")

</div>

I think you can unzip the APK and check if the xml file has been copied into the right place. But looking into this further, there appear to be some challenges accessing the streamingAssets folder on Android: [Reading file from StreamingAssets, Android - #2 by HenryStrattonFW - Questions & Answers - Unity Discussions](https://discussions.unity.com/t/reading-file-from-streamingassets-android/181790/2)

That discussion above should point you in the right direction since others may be having similar issues.

---

<div class="post-metadata">

**Author:** ![zhhqu0305](https://avatars.discourse-cdn.com/v4/letter/z/a9a28c/32.png) [@zhhqu0305](https://forum.magicleap.cloud/u/zhhqu0305)\
**Post date:** [August 18, 2023, 6:00pm UTC](https://forum.magicleap.cloud/t/how-to-locate-vuforia-datasets-in-streamingassets-on-ml2/2357/7 "2023-08-18T18:00:33Z")

</div>

I see what you mean. Seems that the xml file is located at `assets\Vuforia\Sudoku.xml`. I would try with webrequest. Thanks for pointing these out!

---

<div class="post-metadata">

**Author:** ![zhhqu0305](https://avatars.discourse-cdn.com/v4/letter/z/a9a28c/32.png) [@zhhqu0305](https://forum.magicleap.cloud/u/zhhqu0305)\
**Post date:** [August 30, 2023, 8:07pm UTC](https://forum.magicleap.cloud/t/how-to-locate-vuforia-datasets-in-streamingassets-on-ml2/2357/8 "2023-08-30T20:07:12Z")

</div>

A solution to this: basically

```auto
 private string databasePath = "Vuforia/dataset.xml";

```

would work