Cardboard view is upside down

Steve16384 · September 18, 2017, 10:21am

Hi all, I’m in the middle of dabbling with Cardboard, and the only problem I have is that the view is upside down. I started with a fork of GitHub - nordfalk/gvr-android-jme: JMonkeyEngine integration with Google VR SDK . Is there a more up-to-date codebase for starting work on Cardboard?

The issue is mentioned in this thread: Google Cardboard support - #65 by ScienceOfficer but I couldn’t discern if there was a solution, since the thread covers a multitude of issues and fixes to do with VR (one reason why I started this new thread).

Any help much appreciated. Thanks!

grizeldi · September 18, 2017, 11:33am

You can always just set the Y scale of the JmeHarnessFragment to -1 in order to flip it. Should probably work.

Steve16384 · September 18, 2017, 12:22pm

Thanks for the reply. Unfortunately, the project doesn’t have a JmeHarnessFragment (that I could see). My project is based off the StarTravel project. Do you mean AndroidGvrHarness?

Steve16384 · September 18, 2017, 3:42pm

I just tried adding the following line in AndroidGvrHarness:-

@Override
public void setGvrView(GvrView gvrView, boolean enableVrModeFallbacks) {
    // Need to get hold on a view to let AndroidLocator load its assets
    gvrView.setScaleY(-1); // <-- Added this line
    JmeAndroidGvrSystem.setView(gvrView);
    super.setGvrView(gvrView, enableVrModeFallbacks);
}

… but unfortunately, that just meant I had to hold my phone upside down to get Cardboard to start (and the text “Please place your phone…” was backwards); the view was the same.

grizeldi · September 18, 2017, 4:53pm

Then I can’t help you, sorry

Steve16384 · September 19, 2017, 10:12am

Thanks anyway.

I did also try setting “up” to be “down” with this hack:-

    Vector3f.UNIT_Y.y = -1;
    cam.lookAt([...], new Vector3f(0, -1, 0));

…but this didn’t seem to change anything.

Does anyone know if this is a known issue with JME/Cardboard or is it just me? And/or are there any open-source JME projects that anyone knows about that might have solved this problem? Thanks!

Momoko_Fan · September 19, 2017, 2:44pm

This integration looks pretty buggy.

They are updating the game twice, once for each eye. So one eye would show the scene at a slightly time than the other eye. I wouldn’t use something that has such major bugs:

github.com

nordfalk/gvr-android-jme/blob/master/jme-gvr-bridge/src/main/java/com/jme3/system/android/GvrOGLESContext.java#L313


            System.err.println("SEVERE ERROR - EXITING !");
            // com.google.vr.sdk.base.CardboardViewNativeImpl.nativeOnDrawFrame(Native Method) does not kill the app
            // (as of GVR 1.0 / october 1st 2016), so we must do it ourselves to avoid loops
            System.exit(-1);
        }
    } else {
        if (!created.get()) {
            throw new IllegalStateException("onDrawFrame without create");
        }
        listener.update();
        if (autoFlush) {
            renderer.postFrame();
        }
    }
}
@Override
public void onFinishFrame(Viewport viewport) {
}

Steve16384 · September 19, 2017, 3:11pm

Do you have any recommendations for what source I should be using as a good base for a “JME cardboard” app?

Momoko_Fan · September 19, 2017, 7:49pm

Probably you will need to write your own integration. Apparently the VR SDK was changed / upgraded recently and the current integrations were not updated (?)