Checking for AR availability BEFORE launching AR scene?

I am trying to build some logic to test the device after app start to decide whether to allow for AR scene or only conventional 3D scene.
I know we can use

ARSubsystemManager.systemState

to check that but this works only when AR Session component is present in the scene, which means that there needs to be an attempt to initialize AR Session.
This is pretty expensive task that I would like to avoid straight after launching the app.

Is there any way around?

 

Thanks Tim, I tried ARSubsystemManager.checkAvailability() in a coroutine but is doesn't work unless AR Session is initilized - systemState is returning "Unsupported". When checking systemState in AR-enabled scene it works ok.

I guess it is due to these lines of code inside ARSubsystemManager.checkAvailability():

Code (CSharp):

1.             if (sessionSubsystem == null)
2.             {
3.                 systemState = ARSystemState.Unsupported;
4.             }

For me this means you need to try to initialize AR Session first to check whether it will work.
Of course I am considering this for an "AR-optional" app, where depending on the device compatibility the user is given either 3D-only or 3D+AR options.

 

Ended up doing like you said, thanks!

 

Hi @Saicopate, would you be willing to share what you did to establish AR availability? Thx!

 

Sure.
I run this at the start of non-AR scene (replace Debug.Log with your own implementation).

Code (CSharp):

1.    
2. private void OnEnable()
3.     {
4.         ARSubsystemManager.CreateSubsystems();
5.         StartCoroutine(ARSubsystemManager.CheckAvailability());
6.         StartCoroutine(AllowARScene());
7.     }
8.  
9. IEnumerator AllowARScene()
10.     {
11.         while (true)
12.         {
13.             while (ARSubsystemManager.systemState == ARSystemState.CheckingAvailability ||
14.                 ARSubsystemManager.systemState == ARSystemState.None)
15.             {
16.                 Debug.Log("Waiting...");
17.                 yield return null;
18.             }
19.             if (ARSubsystemManager.systemState == ARSystemState.Unsupported)
20.             {
21.                 Debug.Log("AR unsupported");
22.                 yield break;
23.             }
24.             if (ARSubsystemManager.systemState > ARSystemState.CheckingAvailability)
25.             {
26.                 Debug.Log("AR supported");
27.                 yield break;
28.             }
29.         }      
30.     }
31.  

 

Hi
Implemented the solution above.. appears to be working thanks @Saicopate && @tdmowrer

One question.. if using this check in non AR main menu... should I use

Code (CSharp):

1. ARSubsystemManager.DestroySubsystems()

.. after I have completed the check and before I load into my AR scene? as per ARSession?

Or will these subsystems get destroyed gracefully when I unload the main menu scene and load the new AR scene?

Thanks

 

hey @tdmowrer

I have my ARCore Optional app working on devices that do not support arcore etc. And use the above logic to enable AR within my game.

How would I do same for IOS? Such that my app will be made available to all devices running target IOS ver 11... whether they support ARKit or not.. and then allow the logic above to control enabling/disabling AR within my game.

Thanks

 

I don't appear to have that option... Unity 2018.2.6 ARKit preview 17...? Was it introduced in newer version?

Any way to override in xCode? ie. make ARKit optional?

Thanks

 

How can we update this to work in Unity 2019? ARSubsystemManager and ARSystemState no longer seems to exist.

 

Hello,

I tried the "Checking for Device Support" available in the documentation of AR Foundation package. It works in case of supported devices, but in case of unsupported devices it throws below exception and the ARSession.state gets set to 'None':

E/Unity: DllNotFoundException: UnityARCore
at (wrapper managed-to-native) UnityEngine.XR.ARCore.ARCoreSessionSubsystem+NativeApi.UnityARCore_session_construct(UnityEngine.XR.ARCore.ARCoreSessionSubsystem/NativeApi/CameraPermissionRequestProviderDelegate)
at UnityEngine.XR.ARCore.ARCoreSessionSubsystem+Provider..ctor (UnityEngine.XR.ARCore.ARCoreSessionSubsystem subsystem) [0x0000d] in <6d08a2168eb04129816197a2388b8f39>:0
at UnityEngine.XR.ARCore.ARCoreSessionSubsystem.CreateProvider () [0x00000] in <6d08a2168eb04129816197a2388b8f39>:0
at UnityEngine.XR.ARSubsystems.XRSessionSubsystem..ctor () [0x00006] in <9721d2a78fbe4e8db7471dffc3f5f1ba>:0
at UnityEngine.XR.ARCore.ARCoreSessionSubsystem..ctor () [0x00000] in <6d08a2168eb04129816197a2388b8f39>:0
at (wrapper managed-to-native) System.Reflection.MonoCMethod.InternalInvoke(System.Reflection.MonoCMethod,object,object[],System.Exception&)
at System.Reflection.MonoCMethod.InternalInvoke (System.Object obj, System.Object[] parameters) [0x00002] in <c044b3

I am using Unity 2019.1.11, AR Foundation 2.1.1 and I am checking it using below co routine:

Code (CSharp):

1. private IEnumerator CheckAvailability()
2. {
3.    Debug.Log("ARSession.state: " + ARSession.state);
4.    if ((ARSession.state == ARSessionState.None) ||
5.       (ARSession.state == ARSessionState.CheckingAvailability))
6.    {
7.       ShowErrorMessage("Started Checking Availability...");
8.       yield return ARSession.CheckAvailability();
9.    }
10.  
11.    Debug.Log("ARSession.state: " + ARSession.state);
12.    switch (ARSession.state)
13.    {
14.        case ARSessionState.Ready:
15.            Debug.Log("Supported and installed");
16.            LoadARCoreScene();
17.            break;
18.        case ARSessionState.NeedsInstall:
19.            Debug.Log("Supported, not installed, requesting installation");
20.            LoadARCoreScene();
21.            break;
22.        case ARSessionState.Installing:
23.            Debug.Log("Supported apk installing");
24.            LoadARCoreScene();
25.            break;
26.        default:
27.            Debug.Log("Unsupported Device Not Capable");
28.            LoadNonARCoreScene();
29.            break;
30.    }
31. }

@tdmowrer : What am I doing wrong? Please help.

 

Guys please help. Am I missing anything here?

 

hey @thesanketkale
I found signing up to ARSession.stateChanged += ARState; at start worked well for me, also running coroutine CheckARSupportedByMobile at start. hope it helps, cheers

Code (CSharp):

1. IEnumerator CheckARSupportedByMobile()
2.     {
3.         Debug.Log("State " + ARSession.state);
4.  
5.         if ((ARSession.state == ARSessionState.None || ARSession.state == ARSessionState.CheckingAvailability))
6.         {
7.             Debug.Log("Checking AR Availability on mobile device");
8.             yield return ARSession.CheckAvailability();
9.         }
10.     }
11.  
12.     public void ARState(ARSessionStateChangedEventArgs e)
13.     {
14.         switch (ARSession.state)
15.         {
16.             case ARSessionState.None:
17.             case ARSessionState.CheckingAvailability:
18.                 Debug.Log("AR Session - Looking for availability");
19.                 break;
20.             case ARSessionState.Unsupported:
21.                 Debug.Log("AR Session - not available to this mobile device");
22.                 break;
23.             case ARSessionState.NeedsInstall:
24.                 m_Session.enabled = true;
25.                 Debug.Log("AR Session - needs to be installed in mobile device ");
26.                 break;
27.             case ARSessionState.Installing:
28.                 m_Session.enabled = true;
29.                 Debug.Log("AR Session - Installing AR onto mobile device ");
30.                 break;
31.             case ARSessionState.Ready:
32.                 m_Session.enabled = true;
33.                 Debug.Log("AR Session - supported by mobile device and ready to fire up ");
34.                 break;
35.             case ARSessionState.SessionInitializing:
36.                 m_Session.enabled = true;
37.                 Debug.Log("AR session is initializing ");
38.                 break;
39.             case ARSessionState.SessionTracking:
40.                 Debug.Log("AR Session is tracking");
41.                 break;
42.             default:
43.                 Debug.Log("AR Session - no switch worked");
44.                 break;
45.         }
46.     }

 

Hi @Tarrag,

Firstly I must say, thank you for replying. Just after your response, I thought that if the same code was working for you, I must have been doing something wrong in my splash scene or player settings. That's where I figured out that I had added ARSession prefab in my splash screen scene where I was checking the ARCore availability. I had added it thinking that while using ARSession.CheckAvailability() the ARSession object might need initialization via a gameobject in the scene. But apparently I was mistaken as CheckAvailability() being a static coroutine, does not need the ARSession to be initialized. The ARSession script on the ARSession prefab in the scene was actually throwing the exception and not ARSession.CheckAvailability().

Having removed the ARSession prefab from the splash screen, the ARSession.CheckAvailability() is setting the correct ARSessionState now. Thanks again for the reply.

Regards,
Sanket.

 

I am getting unsupported when ground plane works... does this work with vuforia? I'm trying to use arfoundation just to check if the device has arcore, becuase vuforia's
VuforiaRuntimeUtilities.GetActiveFusionProvider isn't working either...
I'm desperate here...

 

ARFoundation's check for ARcore support does work. You can do as shown in previous threads and it should set the ARSession.state to a valid state after couple of seconds of start of ARSession. Just make sure to keep ARSession active and enabled in the scene when you are doing the check. Once your check is done and if you don't need it (like in your case if you are using vuforia) you can destroy the ARSession gameobject.

 

Hi , I am trying the same code to check if the device is supported or not but even in an unsupported device, it opens up the play store to install the ar core service and goes for supported or needs to install case. Any help will be much appreciated.

 

Hi @thesanketkale

If i am trying to implement this code without including ARSession prefab including in my non ar scene. It gives me null ref error at yield return ARSession.CheckAvailability(); line and If i am including the prefab it gives me device supported for coroutine and ar session needs to be installed in switch case for non-supported Ar device. I am finding this bit confusing..can you please guide me on it.
Thanks in Advance.

 

Hi @mitshah, It is required to put the ARSession gameobject with ARSession component enabled on it in the scene where you are trying to check if the device supports AR Foundation. Whether the scene is AR or Non-AR, it doesn't matter, if you want to check device support, ARSession needs to start first and then it will return valid state in ARSession.CheckAvailability(); coroutine.

Now for the issue of unsupported device opening play store to install ARCore, first I want to ask, how did you know if the device is not supported for ARCore? In case if you are following the list mentioned here at Google's website then I would say it does not include all the devices that actually do support ARCore. Maybe the list does not update daily, but I have seen devices coming out of chinese phone companies that support ARCore but not listed there.

The best way to test if the device supports ARCore is to install some apps that only support running on ARCore supported devices. If they work in your device, your device supports ARCore, even if the device manufacturer didn't say it explicitly in its feature list.

Now if your "unsupported device" opens ARCore services, it would only mean that your device supports ARCore. In case if the above approach of testing ARCore supported device via installing an ARCore app does not work then you infer that your device is unsupported and the AR Foundation's check is behaving incorrectly. This would mean you need to create a dummy project with a script that just checks device support and logs result on the screen and then raise a bug report to Unity along with the project and necessary details of your device, unity version and AR foundation version.

Hope this helps.

Regards.

 

Hello. I get errors on older devices from the built project even without calling ARSession.CheckAvailability(). When the GameObject having my script that calls ARSession.CheckAvailability is disabled in the hierarchy, the build passes Google Play review. But when that GameObject is enabled in hierarchy and i build (yet the calls to my checker are commented out so the app doesnt actually call CheckAvailability), I get the following errors reported. In both cases, all other AR components are on game objects that are disabled in Hierarchy at start and would only get SetActive if AR is available.

DllNotFoundException: Unable to load DLL 'UnityARCore': The specified module could not be found.
Stack Trace
UnityEngine.XR.ARCore.ARCoreReferencePointSubsystem+Provider.UnityARCore_refPoints_start () (at <00000000000000000000000000000000>:0)
https://developer.cloud.unity3d.com...12d6/crashes/b9f4cc1342d71e6db05a86852fa79c0c

InvalidOperationException: Can't call "GetChanges" without "Start"ing the reference-point subsystem!
Stack Trace
UnityEngine.XR.ARSubsystems.XRReferencePointSubsystem.GetChanges (Unity.Collections.Allocator allocator) (at <00000000000000000000000000000000>:0)
https://developer.cloud.unity3d.com...12d6/crashes/f7edcf3e72c083d136de39fe6748ad4f

DllNotFoundException: Unable to load DLL 'UnityARCore': The specified module could not be found
UnityEngine.XR.ARCore.ARCorePlaneProvider+Provider.UnityARCore_planeTracking_setPlaneDetectionMode (UnityEngine.XR.ARSubsystems.PlaneDetectionMode mode) (at <00000000000000000000000000000000>:0)
https://developer.cloud.unity3d.com...12d6/crashes/0613bd94a5751fe19c8b94fe26f00a74

and several more like these.

Using Unity 2019.3.3f1, ARFoundation 2.1.4, ARCore XR Plugin 2.1.2
Minimum API Level: Android 4.4 KitKat API level 19
Target API Level: Automatic (highest installed)
Scripting Backend: IL2CPP, .NET 4.x
Target Architectures: ARMv7, ARM64


It's important that my game support as many Android devices as possible, and the AR feature is enabled, by user turning it on, only on devices that support it. Any help or suggestions are appreciated.

 

Hi @linojon, first of all I would suggest not keeping the ARSession object in the scene when you don't need it. As a matter of fact, I would suggest not keep any game object related to AR in the scene till you need it. You can keep prefabs of such game objects and instantiate when needed. So, when you want to check if a device supports AR Foundation, just instantiate the ARSession prefab, keep it active and add a delegate to ARSession.stateChanged listener which on calling should give you whether or not the device supports AR Foundation. In case if the device does, you can continue with your AR related game play and if it doesn't, destroy the ARSession object and tell the user that the device does not support AR.

P.S. - If the game is targeted for non AR supported devices as well, make sure to set ARCore and/or ARkit to Optional in the respective Build Settings.

Now, about the error, its because your game is trying to start the AR subsystem in unsupported devices where ARCore is not available. This is probably due to enabling the ARSessionOrigin object in the scene in an unsupported device(like an older android device). Just be aware that for checking availability of AR Foundation support, you only require an active ARSession object in the scene and nothing else. If its supported only then instantiate other AR Foundation related game objects like the ARSessionOrigin otherwise make sure your scene does not contain anything related to AR Foundation to save your game from such exceptions.

Hope it helps.

 

Hi thanks for the quick reply. This is helpful. Since my post I've moved all the AR objects into a separate additive scene and only load it if the user has a supported device and has requested AR features. However, I had read that we should load the app with ARSession component disabled (on an active gameobject), check for availability, and then only then enable the ARSession component if we can/want? However this still produces a null exception error on s_Instance.CreateSubsystemIfNecessary(); because s_Instance is null until Awake is called. I modified the ARSession.cs file as follows

Code (CSharp):

1.         public bool _disableOnAwake = true;
2.  
3.         void Awake()
4.         {
5.             s_Instance = this;
6.             s_NotTrackingReason = NotTrackingReason.None;
7.  
8.             if (_disableOnAwake)
9.             {
10.                 s_Instance.enabled = false;
11.             }
12.         }
13.  

The reason is i still dont want it to call ARSession#OnEnable (including the Install() stuff) unless/until the user has requested to turn on AR features.

My app now seems to pass the Google Play Review (yaay!). If there's a better way to achieve this (only check Unsupported) with no other actions by the ARSession, can you please clarify with specific code? Thanks!

 

Well, if you just want to check for AR support in a device, you can try this:

Code (CSharp):

1. public GameObject ARSessionPrefab;
2.  
3. private GameObject ARSessionObj;
4. private bool isARSupported;
5.  
6. private void Start()
7. {
8.    StartCoroutine(CheckAvailability());
9. }
10.  
11. private IEnumerator CheckAvailability()
12. {
13.    if (!ARSessionObj)
14.    {
15.        ARSessionObj = Instantiate(ARSessionPrefab);
16.        yield return new WaitForSecondsRealtime(1);
17.    }
18.    if (!Application.isEditor)
19.    {
20.        Debug.Log("ARSession.state: " + ARSession.state);
21.        switch (ARSession.state)
22.        {
23.            case ARSessionState.CheckingAvailability:
24.                Debug.Log("Still Checking Availability...");
25.                ARSession.stateChanged += ARSessionStateChanged;
26.                break;
27.            case ARSessionState.NeedsInstall:
28.                Debug.Log("Supported, not installed, requesting installation");
29.                //TODO: Request ARCore services apk installation and install only if user allows
30.                StartCoroutine(InstallARCoreApp());
31.                break;
32.            case ARSessionState.Installing:
33.                Debug.Log("Supported, apk installing");
34.                StartCoroutine(InstallARCoreApp());
35.                break;
36.            case ARSessionState.Ready:
37.                Debug.Log("Supported and installed");
38.                NextStep(true);
39.                break;
40.            case ARSessionState.SessionInitializing:
41.                Debug.Log("Supported, apk installed. SessionInitializing...");
42.                NextStep(true);
43.                break;
44.            case ARSessionState.SessionTracking:
45.                Debug.Log("Supported, apk installed. SessionTracking...");
46.                NextStep(true);
47.                break;
48.            default:
49.                Debug.Log("Unsupported, Device Not Capable");
50.                NextStep(false);
51.                break;
52.        }
53.    }
54.    else
55.    {
56.        Debug.Log("Unity editor: AR not supported, Device Not Capable");
57.        NextStep(false);
58.    }
59. }
60.  
61. private void ARSessionStateChanged(ARSessionStateChangedEventArgs obj)
62. {
63.    Debug.Log("Inside ARSessionStateChanged delegate...");
64.    switch (ARSession.state)
65.    {
66.        case ARSessionState.CheckingAvailability:
67.            Debug.Log("Still Checking Availability...");
68.            break;
69.        case ARSessionState.NeedsInstall:
70.            Debug.Log("Supported, not installed, requesting installation");
71.            //TODO: Request ARCore services apk installation and install only if user allows
72.            StartCoroutine(InstallARCoreApp());
73.            break;
74.        case ARSessionState.Installing:
75.            Debug.Log("Supported, apk installing");
76.            StartCoroutine(InstallARCoreApp());
77.            break;
78.        case ARSessionState.Ready:
79.            Debug.Log("Supported and installed");
80.            NextStep(true);
81.            break;
82.        case ARSessionState.SessionInitializing:
83.            Debug.Log("Supported, apk installed. SessionInitializing...");
84.            NextStep(true);
85.            break;
86.        case ARSessionState.SessionTracking:
87.            Debug.Log("Supported, apk installed. SessionTracking...");
88.            NextStep(true);
89.            break;
90.        default:
91.            Debug.Log("Unsupported, Device Not Capable");
92.            NextStep(false);
93.            break;
94.    }
95. }
96.  
97. private IEnumerator InstallARCoreApp()
98. {
99.    yield return ARSession.Install();
100.    NextStep(true);
101. }
102.  
103. private void NextStep(bool IsARSupported)
104. {
105.    ARSession.stateChanged -= ARSessionStateChanged;
106.    if (ARSessionObj)
107.    {
108.        Destroy(ARSessionObj);
109.    }
110.    //TODO: Well, continue your game play according to the AR Support boolean or maybe load the AR specific scene
111. }

 

Thanks again! Very helpful, and works. I made a stripped down version for my needs (with switch statements like this). It's just for deciding whether to present an AR option in the UI. The full CheckAvailablity is done only if the player then tries to enable the AR settings.

Code (CSharp):

1.         switch (ARSession.state)
2.         {
3.             case ARSessionState.CheckingAvailability:
4.                 ARSession.stateChanged += _ARSessionStateChanged;
5.                 break;
6.  
7.             case ARSessionState.NeedsInstall:
8.             case ARSessionState.Installing:
9.             case ARSessionState.Ready:
10.             case ARSessionState.SessionInitializing:
11.             case ARSessionState.SessionTracking:
12.                 _isARSupportChecked = true;
13.                 _isARSupported = true;
14.                 _DoneChecking();
15.                 break;
16.  
17.             default:
18.                 _isARSupportChecked = true;
19.                 _isARSupported = false;
20.                 _DoneChecking();
21.                 break;
22.         }

 

@linojon @thesanketkale Thanks for great help,

While checking AR compatibility in non-AR supported android devices, I am being moved to Google Play Services for AR in playstore where it is shown that device is not compatible. But I wanted to know if I need to change something in code or something so that I can know beforehand if device is not compatible and act accordingly. I wish to know AR compatibility without visiting playstore, and if install is required on compatible devices then move to playstore.
Please help if there is any way to do so.

Thanks!

 

Well, this should not happen unless you have checked 'Attempt Update' in ARSession component to true. If your AR implementation is optional, then you should not check that and handle updating Google ARCore Services app in your code only if its compatible.

 

Thanks for the quick and crisp response. It really helped and solved the issue, you are great!