Camera focus mode fails to revert to FOCUS_MODE_CONTINUOUSAUTO on Samsung Flip 7

[workminkyoung]

Summarize the bug:
Camera focus mode fails to revert to FOCUS_MODE_CONTINUOUSAUTO after a touch to focus operation(FOCUS_MODE_TRIGGERAUTO)

Observed problem
I wanted to make the camera operate in FOCUS_MODE_CONTINUOUSAUTO normally, then switch to FOCUS_MODE_TRIGGERAUTO to focus on the tapped area upon a user touch, and then revert back to FOCUS_MODE_CONTINUOUSAUTO after a certain delay.

to do so, i connected SetFocusMode(FocusMode.FOCUS_MODE_CONTINUOUSAUTO) to the OnVuforiaStarted event. I also added code to set the focus region and change the focus mode to FOCUS_MODE_TRIGGERAUTO when a touch input is detected. and then after delay, i set the region back to default and call SetFocusMode(FocusMode.FOCUS_MODE_CONTINUOUSAUTO).

However, while the touch-to-focus itself works fine, continuous autofocus doesn't resume after the delay. The logs show that the focus mode successfully changed back to FOCUS_MODE_CONTINUOUSAUTO, but the camera stays focused on the last tapped area. Strangely, I implemented exposure control the exact same way, and it works perfectly-exposure returns to continuous mode and updates normally. Only the focus is stuck.

Expected result
revert camera focus mode to FOCUS_MODE_CONTINUOUSAUTO after a touch to focus operation(FOCUS_MODE_TRIGGERAUTO)

Other observations
Share any other observations that you made while experiencing the bug.

Reproducible steps

1. Initialize with CONTINUOUSAUTO focus mode
2. Change focus mode to TRIGGERAUTO by touch
3. After delay(2 seconds), set focus region to default and revert focus mode to CONTINUOUSAUTO
4. Camera focus remains fixed

Affected Vuforia Engine version:
v11.4.4

Affected platform:
unity: v6000.1.9, v2022.3.58

• Workstation OS: Windows
• Platform: Unity
• Platform version: v6000.1.9, v2022.3.58

Affected device:

• Name: galaxy flip 7
• Model: sm-f766u1
• OS: Android 35

Screenshots / Video Recordings
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Affected database
If applicable, share your database / dataset which is affected in the issue you're experiecing.

Device or platform logs
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Workaround
Is there currently a workaround that you're using?

Additional comments
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this is my code

    // Start is called before the first frame update
    void Start()
    {
        VuforiaApplication.Instance.OnVuforiaStarted += StartVuforiaFocus;
    }

    void Update()
    {
        if (Input.touchCount > 0)
        {
            var touch = Input.GetTouch(0);
            if (touch.phase == TouchPhase.Ended)
            {
                SetFocusRegion(touch.position, 0.25f);
                SetExposureRegion(touch.position, 0.25f);
                
                ShowTouchIndicator(touch.position);
            }
        }
    }

    void SetFocusRegion(Vector2 focusPosition, float extent)
    {
        Debug.Log("Start Focus Region");
        var regionOfInterest = new CameraRegionOfInterest(focusPosition, extent);
        if (VuforiaBehaviour.Instance.CameraDevice.FocusRegionSupported == true)
        {
            var success = VuforiaBehaviour.Instance.CameraDevice.SetFocusRegion(regionOfInterest);
            if (success)
            {
                if (revertCoroutine != null)
                {
                    StopCoroutine(revertCoroutine);
                }
                 
                bool successF = VuforiaBehaviour.Instance.CameraDevice.SetFocusMode(FocusMode.FOCUS_MODE_TRIGGERAUTO);

                if (successF)
                {
                    if (getFocusCoroutine != null)
                    {
                        StopCoroutine(getFocusCoroutine);
                    }
                    getFocusCoroutine = StartCoroutine(GetFocusMode("Region"));
                    revertCoroutine = StartCoroutine(RevertFocusMode(RevertDelay));
                }
            }
            else
            {
                Debug.Log("Failed to set Focus Mode for region " + regionOfInterest.ToString());
            }
        }
        else
        {
            Debug.Log("Focus region supported: " + VuforiaBehaviour.Instance.CameraDevice.FocusRegionSupported);
            VuforiaBehaviour.Instance.CameraDevice.SetFocusRegion(CameraRegionOfInterest.Default());
        }
    }

    void SetExposureRegion(Vector2 focusPosition, float extent)
    {
        var regionOfInterest = new CameraRegionOfInterest(focusPosition, extent);
        if (VuforiaBehaviour.Instance.CameraDevice.ExposureRegionSupported == true)
        {
            var success = VuforiaBehaviour.Instance.CameraDevice.SetExposureRegion(regionOfInterest);
            if (success)
            {
                VuforiaBehaviour.Instance.CameraDevice.SetExposureMode(ExposureMode.EXPOSURE_MODE_TRIGGERAUTO);
            }
            else
            {
                Debug.Log("Failed to set Exposure Mode for region " + regionOfInterest.ToString());
            }
        }
        else
        {
            Debug.Log("Exposure region supported: " + VuforiaBehaviour.Instance.CameraDevice.ExposureRegionSupported);
            VuforiaBehaviour.Instance.CameraDevice.SetExposureRegion(CameraRegionOfInterest.Default());
        }
    }

    public void StartVuforiaFocus()
    {
        VuforiaBehaviour.Instance.CameraDevice.SetFocusMode(FocusMode.FOCUS_MODE_CONTINUOUSAUTO);
        Toast.instance.Bake($"Initialize Focus mode : {VuforiaBehaviour.Instance.CameraDevice.FocusMode}");
    }
    
    private IEnumerator RevertFocusMode(float delay)
    {
        Debug.Log("Start Revert Focus to CONTINUOUSAUTO");
        yield return new WaitForSeconds(delay);

        bool successR = VuforiaBehaviour.Instance.CameraDevice.SetFocusRegion(CameraRegionOfInterest.Default());
        bool successF = VuforiaBehaviour.Instance.CameraDevice.SetFocusMode(FocusMode.FOCUS_MODE_CONTINUOUSAUTO);
        bool successE = VuforiaBehaviour.Instance.CameraDevice.SetExposureMode(ExposureMode.EXPOSURE_MODE_CONTINUOUSAUTO);

        if (successF)
        {
            if (getFocusCoroutine != null)
            {
                StopCoroutine(getFocusCoroutine);
            }
            getFocusCoroutine = StartCoroutine(GetFocusMode("Revert"));
        }
    }

    private IEnumerator GetFocusMode(string mode)
    {
        yield return new WaitForSeconds(0.5f);

        Debug.Log($"[{mode}] Focus mode : {VuforiaBehaviour.Instance.CameraDevice.FocusMode}");
        Toast.instance.Bake($"[{mode}] Focus mode : {VuforiaBehaviour.Instance.CameraDevice.FocusMode}");
    }

and logs

2025-09-16 02:52:31.552 15342 15364 Info Unity ConfigureVideoBackground
2025-09-16 02:52:31.552 15342 15364 Info Unity Vuforia.MonoCameraConfiguration:ConfigureVideoBackground(Matrix4x4)
2025-09-16 02:52:31.552 15342 15364 Info Unity Vuforia.MonoCameraConfiguration:CheckForSurfaceChanges(Matrix4x4)
2025-09-16 02:52:31.552 15342 15364 Info Unity Vuforia.CameraController:UpdateCamera(Matrix4x4)
2025-09-16 02:52:31.552 15342 15364 Info Unity Vuforia.Internal.Core.StateProcessor:ProcessState(IVuState, IDictionary`2, IVideoBackgroundRenderer, ICameraController, IWorldOriginProvider, DeviceObserver)
2025-09-16 02:52:31.552 15342 15364 Info Unity Vuforia.Internal.Core.Engine:UpdateState()
2025-09-16 02:52:31.552 15342 15364 Info Unity System.Reflection.RuntimeMethodInfo:Invoke(Object, BindingFlags, Binder, Object[], CultureInfo)
2025-09-16 02:52:31.552 15342 15364 Info Unity System.Delegate:DynamicInvokeImpl(Object[])
2025-09-16 02:52:31.552 15342 15364 Info Unity Vuforia.Utility.ExtensionMethods.DelegateHelper:InvokeDelegate(Delegate, Object[])
2025-09-16 02:52:31.552 15342 15364 Info Unity 
2025-09-16 02:52:46.522 15342 15364 Info Unity Start Focus Region
2025-09-16 02:52:46.522 15342 15364 Info Unity CameraSetting:SetFocusRegion(Vector2, Single)
2025-09-16 02:52:46.522 15342 15364 Info Unity CameraSetting:Update()
2025-09-16 02:52:46.522 15342 15364 Info Unity 
2025-09-16 02:52:46.529 15342 15364 Info Unity Start Revert Focus to CONTINUOUSAUTO
2025-09-16 02:52:46.529 15342 15364 Info Unity <RevertFocusMode>d__13:MoveNext()
2025-09-16 02:52:46.529 15342 15364 Info Unity UnityEngine.SetupCoroutine:InvokeMoveNext(IEnumerator, IntPtr)
2025-09-16 02:52:46.529 15342 15364 Info Unity CameraSetting:SetFocusRegion(Vector2, Single)
2025-09-16 02:52:46.529 15342 15364 Info Unity CameraSetting:Update()
2025-09-16 02:52:46.529 15342 15364 Info Unity 
2025-09-16 02:52:47.023 15342 15364 Info Unity [Region] Focus mode : FOCUS_MODE_TRIGGERAUTO
2025-09-16 02:52:47.023 15342 15364 Info Unity <GetFocusMode>d__14:MoveNext()
2025-09-16 02:52:47.023 15342 15364 Info Unity UnityEngine.SetupCoroutine:InvokeMoveNext(IEnumerator, IntPtr)
2025-09-16 02:52:47.023 15342 15364 Info Unity 
2025-09-16 02:52:49.014 15342 15364 Info Unity [Revert] Focus mode : FOCUS_MODE_CONTINUOUSAUTO
2025-09-16 02:52:49.014 15342 15364 Info Unity <GetFocusMode>d__14:MoveNext()
2025-09-16 02:52:49.014 15342 15364 Info Unity UnityEngine.SetupCoroutine:InvokeMoveNext(IEnumerator, IntPtr)
2025-09-16 02:52:49.014 15342 15364 Info Unity 
2025-09-16 02:52:54.885 15342 15364 Info Unity Start Focus Region
2025-09-16 02:52:54.885 15342 15364 Info Unity CameraSetting:SetFocusRegion(Vector2, Single)
2025-09-16 02:52:54.885 15342 15364 Info Unity CameraSetting:Update()
2025-09-16 02:52:54.885 15342 15364 Info Unity 
2025-09-16 02:52:54.888 15342 15364 Info Unity Start Revert Focus to CONTINUOUSAUTO
2025-09-16 02:52:54.888 15342 15364 Info Unity <RevertFocusMode>d__13:MoveNext()
2025-09-16 02:52:54.888 15342 15364 Info Unity UnityEngine.SetupCoroutine:InvokeMoveNext(IEnumerator, IntPtr)
2025-09-16 02:52:54.888 15342 15364 Info Unity CameraSetting:SetFocusRegion(Vector2, Single)
2025-09-16 02:52:54.888 15342 15364 Info Unity CameraSetting:Update()
2025-09-16 02:52:54.888 15342 15364 Info Unity 
2025-09-16 02:52:55.386 15342 15364 Info Unity [Region] Focus mode : FOCUS_MODE_TRIGGERAUTO
2025-09-16 02:52:55.386 15342 15364 Info Unity <GetFocusMode>d__14:MoveNext()
2025-09-16 02:52:55.386 15342 15364 Info Unity UnityEngine.SetupCoroutine:InvokeMoveNext(IEnumerator, IntPtr)
2025-09-16 02:52:55.386 15342 15364 Info Unity 
2025-09-16 02:52:57.387 15342 15364 Info Unity [Revert] Focus mode : FOCUS_MODE_CONTINUOUSAUTO
2025-09-16 02:52:57.387 15342 15364 Info Unity <GetFocusMode>d__14:MoveNext()
2025-09-16 02:52:57.387 15342 15364 Info Unity UnityEngine.SetupCoroutine:InvokeMoveNext(IEnumerator, IntPtr)
2025-09-16 02:52:57.387 15342 15364 Info Unity 
2025-09-16 02:53:06.543 15342 15364 Info Unity Start Focus Region
2025-09-16 02:53:06.543 15342 15364 Info Unity CameraSetting:SetFocusRegion(Vector2, Single)
2025-09-16 02:53:06.543 15342 15364 Info Unity CameraSetting:Update()
2025-09-16 02:53:06.543 15342 15364 Info Unity 
2025-09-16 02:53:06.546 15342 15364 Info Unity Start Revert Focus to CONTINUOUSAUTO
2025-09-16 02:53:06.546 15342 15364 Info Unity <RevertFocusMode>d__13:MoveNext()
2025-09-16 02:53:06.546 15342 15364 Info Unity UnityEngine.SetupCoroutine:InvokeMoveNext(IEnumerator, IntPtr)
2025-09-16 02:53:06.546 15342 15364 Info Unity CameraSetting:SetFocusRegion(Vector2, Single)
2025-09-16 02:53:06.546 15342 15364 Info Unity CameraSetting:Update()
2025-09-16 02:53:06.546 15342 15364 Info Unity 
2025-09-16 02:53:07.043 15342 15364 Info Unity [Region] Focus mode : FOCUS_MODE_TRIGGERAUTO
2025-09-16 02:53:07.043 15342 15364 Info Unity <GetFocusMode>d__14:MoveNext()
2025-09-16 02:53:07.043 15342 15364 Info Unity UnityEngine.SetupCoroutine:InvokeMoveNext(IEnumerator, IntPtr)
2025-09-16 02:53:07.043 15342 15364 Info Unity 
2025-09-16 02:53:09.045 15342 15364 Info Unity [Revert] Focus mode : FOCUS_MODE_CONTINUOUSAUTO
2025-09-16 02:53:09.045 15342 15364 Info Unity <GetFocusMode>d__14:MoveNext()
2025-09-16 02:53:09.045 15342 15364 Info Unity UnityEngine.SetupCoroutine:InvokeMoveNext(IEnumerator, IntPtr)
2025-09-16 02:53:09.045 15342 15364 Info Unity 
2025-09-16 02:53:15.833 15342 15364 Info Unity Start Focus Region
2025-09-16 02:53:15.833 15342 15364 Info Unity CameraSetting:SetFocusRegion(Vector2, Single)
2025-09-16 02:53:15.833 15342 15364 Info Unity CameraSetting:Update()
2025-09-16 02:53:15.833 15342 15364 Info Unity 
2025-09-16 02:53:15.835 15342 15364 Info Unity Start Revert Focus to CONTINUOUSAUTO
2025-09-16 02:53:15.835 15342 15364 Info Unity <RevertFocusMode>d__13:MoveNext()
2025-09-16 02:53:15.835 15342 15364 Info Unity UnityEngine.SetupCoroutine:InvokeMoveNext(IEnumerator, IntPtr)
2025-09-16 02:53:15.835 15342 15364 Info Unity CameraSetting:SetFocusRegion(Vector2, Single)
2025-09-16 02:53:15.835 15342 15364 Info Unity CameraSetting:Update()
2025-09-16 02:53:15.835 15342 15364 Info Unity 
2025-09-16 02:53:16.333 15342 15364 Info Unity [Region] Focus mode : FOCUS_MODE_TRIGGERAUTO
2025-09-16 02:53:16.333 15342 15364 Info Unity <GetFocusMode>d__14:MoveNext()
2025-09-16 02:53:16.333 15342 15364 Info Unity UnityEngine.SetupCoroutine:InvokeMoveNext(IEnumerator, IntPtr)
2025-09-16 02:53:16.333 15342 15364 Info Unity 
2025-09-16 02:53:18.336 15342 15364 Info Unity [Revert] Focus mode : FOCUS_MODE_CONTINUOUSAUTO
2025-09-16 02:53:18.336 15342 15364 Info Unity <GetFocusMode>d__14:MoveNext()
2025-09-16 02:53:18.336 15342 15364 Info Unity UnityEngine.SetupCoroutine:InvokeMoveNext(IEnumerator, IntPtr)
2025-09-16 02:53:18.336 15342 15364 Info Unity 
2025-09-16 02:53:24.072 15342 15364 Info Unity Start Focus Region
2025-09-16 02:53:24.072 15342 15364 Info Unity CameraSetting:SetFocusRegion(Vector2, Single)
2025-09-16 02:53:24.072 15342 15364 Info Unity CameraSetting:Update()
2025-09-16 02:53:24.072 15342 15364 Info Unity 
2025-09-16 02:53:24.075 15342 15364 Info Unity Start Revert Focus to CONTINUOUSAUTO
2025-09-16 02:53:24.075 15342 15364 Info Unity <RevertFocusMode>d__13:MoveNext()
2025-09-16 02:53:24.075 15342 15364 Info Unity UnityEngine.SetupCoroutine:InvokeMoveNext(IEnumerator, IntPtr)
2025-09-16 02:53:24.075 15342 15364 Info Unity CameraSetting:SetFocusRegion(Vector2, Single)
2025-09-16 02:53:24.075 15342 15364 Info Unity CameraSetting:Update()
2025-09-16 02:53:24.075 15342 15364 Info Unity 
2025-09-16 02:53:24.572 15342 15364 Info Unity [Region] Focus mode : FOCUS_MODE_TRIGGERAUTO
2025-09-16 02:53:24.572 15342 15364 Info Unity <GetFocusMode>d__14:MoveNext()
2025-09-16 02:53:24.572 15342 15364 Info Unity UnityEngine.SetupCoroutine:InvokeMoveNext(IEnumerator, IntPtr)
2025-09-16 02:53:24.572 15342 15364 Info Unity 
2025-09-16 02:53:25.558 15342 15364 Info Unity Vuforia Stopped
2025-09-16 02:53:25.558 15342 15364 Info Unity Vuforia.Internal.Core.Engine:Stop(Action)
2025-09-16 02:53:25.558 15342 15364 Info Unity Vuforia.Internal.Core.Engine:Pause()
2025-09-16 02:53:25.558 15342 15364 Info Unity System.Reflection.RuntimeMethodInfo:Invoke(Object, BindingFlags, Binder, Object[], CultureInfo)
2025-09-16 02:53:25.558 15342 15364 Info Unity System.Delegate:DynamicInvokeImpl(Object[])
2025-09-16 02:53:25.558 15342 15364 Info Unity Vuforia.Utility.ExtensionMethods.DelegateHelper:InvokeDelegate(Delegate, Object[])
2025-09-16 02:53:25.558 15342 15364 Info Unity Vuforia.Utility.ExtensionMethods.DelegateHelper:InvokeWithExceptionHandling(Action`1, T)

[ptc-emaggio]

@workminkyoung thanks for the report. Would you mind attaching the logs?

[workminkyoung]

output.zip
@ptc-emaggio I've added the logs and the code, and I’ve also attached the recorded video.

[ptc-emaggio]

@workminkyoung thanks for the extra information. We have tried on a different Android device and we cannot reproduce the issue. Is the problem still there even if you increase the "revert" delay to let's say 5 seconds?

[workminkyoung]

@ptc-emaggio It was the same even after increasing the delay to 5 seconds. If it’s not reproducible on your side, it might be something I did wrong, so I’ll double-check. Could you let me know which Android device you tested on?

[ptc-emaggio]

@workminkyoung we tested on a Pixel 6a. Note that focus behavior is not uniform across devices. It is quite possible that there is indeed a bug, but only affecting the galaxy flip 7. Unfortunately we do not have this specific device to try to repro. It would be good to know if you can reproduce the same issue on a different device.

[workminkyoung]

@ptc-emaggio I tested it on a Galaxy S23 Ultra, and I confirmed that it reverts to CONTINUOUSAUTO mode. Like you said, it seems to be a bug specifically with the Flip 7.

[ptc-emaggio]

@workminkyoung thanks for the test. We will try to reproduce this on other Samsung devices. If this is a reasonably common behavior we can try to fix it in Engine SDK. If it is specific to the Flip 7, this would indicate that this device does not conform to the Android API specs and there might be an issue with the Camera driver implementation which has to be solved by Samsung (or the camera driver provider).

[workminkyoung]

Thanks for the help. I'll let you know if I find anything else, and I'd appreciate it if you could keep me updated.