Hi Cascho,

since you have an iOS-specific issue, I think it does not fit entirely on this thread;

could you create a new thread please and provide as many information as possible such as exact device model (e.g. iPad 3, iPhone 5s, etc.), iOS version and any other relevant information as suggested here:

https://developer.vuforia.com/forum/device-support/how-report-device-issue

Thanks.

I have blackscreen on IOS with :

vuforia-unity-android-ios-3-0-5 and

vuforia-unity-android-ios-3-0-9

Create empty project, import package, put framemarker+arcam....: Blackscreen!

AlessandroB wrote:

Let me clarify better:  the point is that Unity works on PC only when using Play Mode , i.e. for testing / preview (but cannot be deployed as an .exe to PC, since Vuforia does not allow this... the app caa only be deployed to Android and iOS)... so, the solution that you were referring to is basically only valid as long as you run it in Play Mode in Unity (but cannot build an ".exe" out of it).

Now, having said this, it appears that nicholasyummi seems to have some more general solution......

ah ok, I see now.

I meant the player, ofc.  "after making a woking project on PC player"

I tried the mentioned GUI label trick, but no success.

So it seems a dead-end. The original Vuforia AR camera works on mobile, but not with more cameras for Dive or Oculus.

The background camera replacement works with Dive, but no camera image.

nicholasyummi wrote:

BigaCubensis wrote:

I'm using the 2.8.7 version. There is a more recent one?

We are using 2.8.7. No problems. Our background texture thing actually didn't work in this new version anyway. So we reimplemented carefully and it works :)

I see.

Well the Vuforia started as a very inspiring and funny thing, with awesome possibilities for future.

The ones who learned it quickly, already started a company and working on commercial products.

So information like guides and code fragments became rare, as nobody want to give freely the solutions which are the base of their product.

I understand this also, but "we reimplemented carefully" doesnt help me, to a Unity + Vuforia noob, too much :)

Though  an information too, what I made in last 2 weeks with blood and pain, based on the recommended background texture and camera, I can throw out... :)

cheers,

Gabor

BigaCubensis wrote:

I'm using the 2.8.7 version. There is a more recent one?

We are using 2.8.7. No problems. Our background texture thing actually didn't work in this new version anyway. So we reimplemented carefully and it works :)

I dont understand this... I deployed it on Android and doesnt work there... and works on PC where is not supported? :)

Let me clarify better:  the point is that Unity works on PC only when using Play Mode , i.e. for testing / preview (but cannot be deployed as an .exe to PC, since Vuforia does not allow this... the app caa only be deployed to Android and iOS)... so, the solution that you were referring to is basically only valid as long as you run it in Play Mode in Unity (but cannot build an ".exe" out of it).

Now, having said this, it appears that nicholasyummi seems to have some more general solution......

nicholasyummi wrote:

Just a quick FYI, we no longer use the workaround described previously, as with the latest version of Vuforia (implemented according to provided examples) it appears unneccessary. Our most recent tests show good operation across the vast majority of devices.

I'm using the 2.8.7 version. There is a more recent one?

Just a quick FYI, we no longer use the workaround described previously, as with the latest version of Vuforia (implemented according to provided examples) it appears unneccessary. Our most recent tests show good operation across the vast majority of devices.

I dont understand this... I deployed it on Android and doesnt work there... and works on PC where is not supported? :)

I arrived to the problem described in this topic that it doesnt work on my mobile.

Indeed, Vuforia can be deployed on Android or iOS, not on Win/Mac PC. I am not aware of any news/updates or plans to support the PC platform, at present.

AlessandroB wrote:

- Nicholas has provided a nice workaround, which relies on using the Background Texture Access approach (see Background Texture Access sample)

 

just found the topic, after making a woking project on PC player, following the instructions of topic:

https://developer.vuforia.com/forum/unity-3-extension-technical-discussion/working-2-cameras

but finally I arrived to the problem described in this topic that it doesnt work on my mobile.

my app is done with Background Texture Access, but still doesnt work with Samsung SII... 

maybe someone found a solution?

thanks,

Gabor

Just to summarize a bit and bring some key-points out of this long thread:

- the issue seems related/caused (based on the various reports below) by the "combined" use of ARCamera + a standard Unity camera + some GUI elements

- Nicholas has provided a nice workaround, which relies on using the Background Texture Access approach (see Background Texture Access sample)

- there is not yet a clear reproducible procedure to trigger the issue starting from a basic Vuforia sample or a simple scene setup (except the simple procedure reported by Nicholas, but only showing the issue on Nexus 4, not on other devices)

- if anyone can bring a clear, concise step-by-step procedure to reproduce the issue, he is more than welcome, so we can investigate this further.

I too am curious as to the workaround as it's not working for me. It has to do with a GUI.label??? I'm not using ongui() in my scene at all...where should I add this label? 

If I use a quad with the button on it and raycast from the camera to detect a button "press" will that fix the black screen? I deleted my extra camera and all GUITextures/guiText from the scene and it's still black screen on devices....

well, I'm not talking on using two at the same time.

it's a simple scene in Unity, using main camera, tracking one target, showing one simple 3D model.

Nexus 4 with 4.3 running it great.

Galexy 4 running it great, even few others, 

but Galexy 3 and a too many others showing black screen instead of the camera preview.

i thought this thread is about that. after all - googleling the issue led me to understand that i'm not the only one having this problem.

so maybe someone from Unity-Vuforia team will investigate the issue? It's a true deal breaker issue.

in my country most of the smartphone are galexy 3 variations. i can not publish an app that will show a black screen.

There is a simple work around detailed in the thread, and this issue is specific to a subset of  Androis devices x OS version when using multiple cameras. 

Hi

This issue is really a big disappointment for me.

i chose vuforia and unity as my primary platform for my new media company.

the app is ready, running great on nexus 4.

ios app is on it's way.

the website is ready with all the targets prints on their way...

and now i notice that 2 out of 3 android devices out there - see a black screen while runing the app.

i came across this post and see i'm not the only one....

but is there some solution to it?

why it's not written in font size 100 in the SDK page?

all these strong smartphone (galexy 3, HTC etc) can not run the app! what is the point?

is it the alarm call to change my mind and try Wikitude?

I'm using a separate camera as well for GUI and while it was working at first it began giving the blackscreen when deployed to device at some point on the image target scene. HOWEVER, the video playback scene is still working, but I haven't added any GUI stuff to it yet, but it spawns a video texture that plays a door opening to reveal a 3d room behind, then a 3d object animates from inside the room.  It all plays fine on the video texture scene, but I'm only using the tracking from it, not a video texture from Vuforia but rather the mobile movie texture plugin for unity (which supports alpha video instead of png sequence)

For us the GUI is really basic, just a "take photo" icon and an exit/menu icon which are shown by the ARCamera. When you press the "Photo" icon it turns on the 3rd camera which shows several buttons and a plane with the captured image displayed in the app with buttons to save to gallery, share, or discard.

AlessandroB wrote:

Thanks for this detailed report.

One thing I seem to understand in your description is that you are using other Cameras next to the ARCamera of Vuforia; or is it my misunderstanding ?

 

Hi Alessandro,

We're using another camera to render user-interface elements in front of the Vuforia background video. This is necessary, because otherwise how can users navigate out of scan mode?

I wouldn't say "next to" is accurate. The elements are actually visually in front of stuff being rendered by Vuforia. Also, "ARCamera" is not accurate either, because it's actually the output of the "BackroundCamera" we are rendering in front of. We don't use the actual "ARCamera" for anything (we use scanning for triggering unlocks, not showing dinosaurs!). Moreover, with respect to the Unity scene, our gui camera is in no way next to any other camera – neither in space nor in the object hierarchy. Separating cameras in this way, and layering output visually, is standard practice.

Nicholas Bellerophon
YummiMedia

I can confirm we're having the same issue on a Nexus 7 tablet. We're rendering another camera on top of the video feed, and are seeing a blank screen only on this device. I'll try the video texture method you've mentioned below.

Thanks for this detailed report.

One thing I seem to understand in your description is that you are using other Cameras next to the ARCamera of Vuforia; or is it my misunderstanding ?

Hi,

I'm happy to report that we have finally managed to overcome this issue on the majority of our test devices.

The solution was to use Vuforia's alternate rendering path, importing the "VideoTextureBehaviour" script from the "backgroundtextureaccess-2-6-7" sample and implementing it in our project. We didn't need the funky black & white, image warping shader, but it's cool to know stuff like that is possible anyway.

We believe that the normal, native rendering path does not work for projects that wish to use other cameras to show ui elements on top of the Vuforia video background, although we're not completely clear why this is or precisely what the trigger points for failure are.

Concerning the Nexus 4, we got that working too, but we think that weird GUI.Button bug still exists – we simply don't use any in our project.

Thanks for help from Vuforia team. Perhaps consider making alt rendering path the default? Surely most production projects will need ui on top of video?

Hopefully anyway this thread will help others.

Nicholas Bellerophon
YummiMedia

Thanks for the update;  keep us posted with your findings.

I've been testing more now, and it appears that the test case I provided to you is indeed very limited to the Nexus 4. Sadly, our app continues to fail on many phones.

So I have to conclude that our problem is not related to the use of GUI.Button specifically, and I will now remove the Nexus 4 from the test device pool for testing of this issue.

I will post again if I find another cause, and this time will be sure to verify on at least two different devices before posting.

Thanks,

Nicholas Bellerophon
YummiMedia

OK, 

I tried here on a Nexus 10 with Android 4.3 and it works.

So, based on your results, sounds really specific to the Nexus 4.

Further testing:

HTC Sensation, Android 4.0.3 - Vuforia works

Samsung gt-i9300, Android 4.1.2 - Vuforia works

HTC-one, Android 4.2.2 - Vuforia works

Huawei y-300, Android 4.1.1 - Vuforia works

Samsung gt-i9505, Android 4.2.2 - Vuforia works

Hi,

Thanks for attempting to repro this. I will attempt to re-repro it here. The device I am currently testing with is a Nexus 4 using Android 4.3.

EDIT: Okay, I have reproduced the issue on the Nexus 4 using precisely the steps outlined, even using your exact names and code form for the script. In case this is a case of different build settings, here are mine (default as far as I know?):

Texture Compression: don't override
Google Android Project: NO
Development Build: NO

Use 32-bit Display Buffer: YES
Use 24-bit Depth Buffer: NO

Static Batching: YES
Dynamic Batching: YES
GPU Skinning: YES
Minimum API Level: Android 2.0.1 'Eclair' (API level 6)
Device Filter: ARMv7 only
Install Location: Prefer External
Graphics Level: OpenGL ES 2.0
Submit HW Statistics: YES
Internet Access: Auto
Write Access: Internal Only

API Compatibility Level: .NET 2.0 Subset
Stripping Level: Disabled
Enable Internal Profiler: NO
Optimize Mesh Data: NO
 

Nicholas Bellerophon
YummiMedia

Hi, thanks for the detailed procedure.

I'm trying to reproduce this, but I did not manage on Android device (not tested yet on iOS).

This is the GUI script I'm using (let me know if something is not exactly as you meant it), which is attached to the empty gameobject as you suggest.

public class GUITest : MonoBehaviour {

	void OnGUI() {
		GUI.Button (new Rect(50,50,100,50), "Hello");	
	}
}

Could you indicate a specific device where you see this happening ?

Hi,

Okay, we now have a definitive, reproducible failure case of Vuforia in Unity 4.2.2.

1. Make a clean project.

2. Install Vuforia 2.6.7.

3. Delete the main camera from the scene (this step may be optional).

4. Drag the ARCamera prefab into the scene.

5. Create an empty game object in the scene.

6. Create a C# script with a call to OnGUI in it. Within the OnGUI call, code a GUI.Button with a Rect and text.

7. Drag the C# script onto the empty game object in the scene.

8. Press play. Notice that everything works in-editor as expected.

9. Deploy to a mobile device. iOS (any) and Android (4.2+) at least appear to be affected.

10. Notice there is no background video render.

JUST FOR FUN

11. Remove the call to the GUI.Button from your script and redeploy.

12. Notice Vuforia works again!

Hopefully this gives you guys enough info to be able to repro this issue and tackle it. Meanwhile, we will try the alternate rendering method mentioned earlier.

EDIT: we have now tested doing the same thing in the "backgroundtextureaccess-2-6-7" sample. This also fails, with a message at the top of the screen "Sample Error" and "The BackgroundTextureAccess Sample requires OpenGL ES 2.0". However, we are set to OpenGL ES 2.0 in player settings.

We are now quite stuck. Please help!

Many thanks,

Nicholas Bellerophon
YummiMedia

Actually I did have to add some permissions and activities from the unishare to the qcar manifest. 

My manifest looks like:

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android" package="com.qualcomm.QCARUnityPlayer" android:versionCode="1" android:versionName="1.0">
  <uses-sdk android:minSdkVersion="8" />
  <uses-feature android:name="android.hardware.camera" />
  <supports-screens android:smallScreens="true" android:normalScreens="true" android:largeScreens="true" android:anyDensity="true" />
  <uses-permission android:name="android.permission.WAKE_LOCK" />
  <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
  <uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />
  <uses-permission android:name="android.permission.INTERNET" />
  <uses-permission android:name="android.permission.CAMERA" />
  <uses-permission android:name="android.permission.READ_PHONE_STATE" />
  <application android:icon="@drawable/app_icon" android:label="@string/app_name" android:theme="@android:style/Theme.NoTitleBar.Fullscreen" android:debuggable="false">
    <activity android:name="com.qualcomm.QCARUnityPlayer.QCARPlayerProxyActivity" android:label="@string/app_name" android:screenOrientation="portrait" android:configChanges="fontScale|keyboard|keyboardHidden|locale|mnc|mcc|navigation|orientation|screenLayout|screenSize|smallestScreenSize|uiMode|touchscreen">
      <intent-filter>
        <action android:name="android.intent.action.MAIN" />
        <category android:name="android.intent.category.LAUNCHER" />
      </intent-filter>
    </activity>
    <activity android:name="com.qualcomm.QCARUnityPlayer.QCARPlayerActivity" android:label="@string/app_name" android:screenOrientation="portrait" android:configChanges="fontScale|keyboard|keyboardHidden|locale|mnc|mcc|navigation|orientation|screenLayout|screenSize|smallestScreenSize|uiMode|touchscreen">
    </activity>
    <activity android:name="com.qualcomm.QCARUnityPlayer.QCARPlayerNativeActivity" android:label="@string/app_name" android:screenOrientation="portrait" android:configChanges="fontScale|keyboard|keyboardHidden|locale|mnc|mcc|navigation|orientation|screenLayout|screenSize|smallestScreenSize|uiMode|touchscreen">
      <meta-data android:name="android.app.lib_name" android:value="unity" />
      <meta-data android:name="unityplayer.ForwardNativeEventsToDalvik" android:value="false" />
    </activity>
    <activity android:name="com.unity3d.player.VideoPlayer" android:label="@string/app_name" android:screenOrientation="portrait" android:configChanges="fontScale|keyboard|keyboardHidden|locale|mnc|mcc|navigation|orientation|screenLayout|screenSize|smallestScreenSize|uiMode|touchscreen">
    </activity>
    <activity android:name="com.unity3d.player.UnityPlayerProxyActivity" android:label="@string/app_name" android:configChanges="fontScale|keyboard|keyboardHidden|locale|mnc|mcc|navigation|orientation|screenLayout|screenSize|smallestScreenSize|uiMode|touchscreen">
      <intent-filter>
        <action android:name="android.intent.action.MAIN" />
        <category android:name="android.intent.category.LAUNCHER" />
      </intent-filter>
    </activity>
    <activity android:name="com.unisocial.WebViewActivity" android:theme="@android:style/Theme.NoTitleBar.Fullscreen" android:configChanges="fontScale|keyboard|keyboardHidden|locale|mnc|mcc|navigation|orientation|screenLayout|screenSize|smallestScreenSize|uiMode|touchscreen">
    </activity>
    <activity android:name="com.unity3d.player.UnityPlayerActivity" android:label="@string/app_name" android:configChanges="fontScale|keyboard|keyboardHidden|locale|mnc|mcc|navigation|orientation|screenLayout|screenSize|smallestScreenSize|uiMode|touchscreen">
    </activity>
    <activity android:name="com.unity3d.player.UnityPlayerNativeActivity" android:label="@string/app_name" android:configChanges="fontScale|keyboard|keyboardHidden|locale|mnc|mcc|navigation|orientation|screenLayout|screenSize|smallestScreenSize|uiMode|touchscreen">
      <meta-data android:name="android.app.lib_name" android:value="unity" />
      <meta-data android:name="unityplayer.ForwardNativeEventsToDalvik" android:value="false" />
    </activity>
    <activity android:name="com.unity3d.player.VideoPlayer" android:label="@string/app_name" android:configChanges="fontScale|keyboard|keyboardHidden|locale|mnc|mcc|navigation|orientation|screenLayout|screenSize|smallestScreenSize|uiMode|touchscreen" android:screenOrientation="portrait">
    </activity>
  </application>
</manifest>
<!-- android:installLocation="preferExternal" -->

I'm testing on a samsung tablet, not sure what version of android it's running. It's a samsung galaxy tab 2, the 7" one.  I believe it's android version 4.1 or 4.2...

On which version of android have you tested. I change the android manifest to the old one with  unity 4.2.2f1 and unishare and it works on android 3.1 but it doesnt work on 4.0 or higher so the problem  is still there for me...

Thanks for reporting that. So Unishare runs correctly using the Vuforia manifest, but the manifest generated by Unishare interferes w/ Vuforia? - and that's only generated on import?

I got unity 4.2.2f1 version working with vuforia image targets and video playback and with the unishare plugin. 

After creating a new project with 4.2.2f1 I imported the video playback example and the image targets example. THEN I imported an androidmanifest file from an older version of unity that was working with vuforia and 4.2.2f1 is now working with the newest version of vuforia, no more blackscreen.

edit:: I noticed the unishare plugin was overwriting the manifest file, so I saved the qcar one and after importing everything + the unishare plugin, overwrote it back to the old qcar manifest and now everything works, vuforia and the unishare plugin. 

Hi again,

Further development: we have reproduced exactly the same issue on iOS (blackscreen, GUI.Label workaround). This is actually a really good thing, as it means we're not dealing with anything in the native realm.

We are now pretty convinced this issue lies at the intersect of how we are using Unity, and how QCAR does its texture rendering. It definitely is related to having an additional camera in the scene, though that doesn't appear to be the only element required to repro. I think there's something specific about what our second camera is doing that we still need to discover. We'll post more information as we get it.

Nicholas Bellerophon
YummiMedia

Same problem here black screen on devices Android +4.0 with unity using other plugins as Unishare, still trying to figure out how to fix it. (working great on samsung table with android 3.1)

Hi all,

Thanks for replies and suggestions. We will investigate using the alternative rendering path, as well as getting the GUI.Label workaround to be useful, in the coming days.

I should note here that many plugins which assist with Facebook and / or Twitter integration require some extra code in the Unity activities on Android. Make sure you check your manifest for the classnames that are being used for the three main Unity activities (Proxy, Legacy, Native). Our solution for incorporating both Vuforia and other plugins has been to write our own custom activities that do whatever each plugin requires, in addition to what Vuforia requires. Conveniently, almost all Vuforia functionality lives in a "Shared" class separate from the activities themselves. This makes the job much easier.

I point this out here because this might be the underlying cause of Vuforia misbehaviour if addition / removal of a Facebook plugin appears to be key factor in testing.

However, we do not think the evidence points to this being the cause of the problem we are currently facing. On the other hand we can't rule out interference by other plugins completely, because as stated we weren't able to replicate the issue in a clean project yet.

Nicholas Bellerophon
YummiMedia

You might check the plugin's Android manifest to see if there are camera permissions. Vuforia needs to have exclusive access to the camera. We've seen problems with other plugins that use the camera, like some of Prime 31's.

If you simply need to be able capture screen grabs, see: https://developer.vuforia.com/resources/dev-guide/unity-screenshots

It's called Unishare: https://www.assetstore.unity3d.com/#/search/unishare

It might try to access the camera to send a screenshot but I'm not sure. I'm trying to add functionality so you can take a screenshot, see it applied to a texture with a button to share or email, so you could take an image of the AR stuff...........but it's a real pita to implement for some reason. 

What's the plugin that you're using, does it attempt to access the camera?

I definitely have the problem on unity 4.1.5 as well after importing another plugin called unishare(facebook and twitter plugin)........... these are all iin completely different projects named completely differently when I build it, each opened with a different version of unity.

I installed the videobackground scene on 4.2.2 and it worked. I imported another plugin and it started giving the black screen. I made another project and imported the videobackground into it and it works again...until I import another plugin, then it blackscreens. EVEN on 4.1.5 unity version.

About to test the backgroundtexture now....

EDIT:: Backgroundtexture scene is blackscreen in the editor on 4.2.2...if you point the camera at the target you see the pot but only black in the background....I imported it into the same project as the videobackground and it's blackscreen in the editor while the videoscene still works in 4.2.2

Try the Background Texture Access sample as well. That uses a different render path for drawing the video background. Also be sure to delete your app between tests. 4.1.5 shouldn't be presenting any problems

I should have checked here first. My boss, and therefore I, was pulling my hair out yesterday. As of right now it's blackscreening on unity 4.1.5, which was a working build for the past month. 

I had vuforia working fine on 4.2.1, but I believe for another plugin(facebook) I had to upgrade to unity 4.2.2. There, I remade my 4.1.5 vuforia project from scratch with unity 4.2.2 and it works in the editor perfectly but the android device is a black screen.

So I went back to my 4.1.5 build, and tried adding the facebook stuff to it, and it started (and still is) doing a blackscreen on all the android builds which were working fine early yesterday until I added the FB plugin.

THEN, I just made a new project with unity 4.2.2 and only imported the vuforia video playback demo, made a build, and it DOES WORK with unity 4.2.2 on andriod........................ so it seems to only be the image target based scenes and maybe others that are messed up...

So now I'm going to try making my original scene in the video playback scene in 4.2.2, and try to use 3d models instead of the videos...cause the tracking works fine....maybe a manifest conflict or something.

We have some known issues w/ the later 4.x Unity releases. I'm checking on which specifically affect 4.2.2, but I think it's going to require a workaround, potentially the one you've discovered. We've also been recommending using a background texture for rendering the camera background for certain versions - see the Background Texture Access sample for an example. 

Ah I've spent 2 days trying to figure out why the hell it runs in the editor and yet the device only shows black along with a couple guitextures.

I'm trying to incorporate the facebook api and when I tried to add that to a 4.1.5 working vuforia build it gave it a black screen there as well...

Hrm...

We've allocated this dev cycle specifically to move to the latest stable versions of our various tools and plugins. So Unity 4.2.2 is part of that, as is the latest Vuforia and other plugins.

We can potentially roll back for testing purposes, but that will take some time which I'm not sure we have.

FYI, I finally got the GUI.Label trick to work in our scene with other stuff... by turning off the HUD camera which displays that stuff :)

Any further ideas? Can I assist you in reproducing the issue on your end?

Nicholas Bellerophon
YummiMedia

Can you roll back to Unity 4.2.1?