XiaoMi/Oculus VR Hybrid App

This guide will help you to reproduce some controller issues in XiaoMi/Oculus hybrid app

Envrionment

• Mac OSX 10.13.4
• Unity 2017.4.0f1
• Oculus Mobile SDK v1.7
• Xiaomi Unity SDK v1.4.5 or Oculus Unity SDK v1.26.0

Description

We are making a hybrid VR app using both Xiaomi(or Oculus) Unity VR SDK and Oculus native SDK. We are using the Oculus sample VrController as the native code and made some minimal changes so it can be launched within the Unity app.

The native sample VrController app works well. However, if it is launched from the Unity-built app. The back/home keys are not working. Other keys are working fine. Dive into the code of vrcontroller.cpp line 982 vrapi_GetCurrentInputState() gets value 0 for remoteInputState when back/home is clicked

Quick Setup

1. For Xiaomi headset, use the demo scene 360ViewController from Xiaomi Unity SDK For Oculus Go/Gear VR, use the demo scene GearVrControllerTest from Oculus Unity SDK
2. Clone this repo
3. Copy the following aar libraries into the Unity project
   • UnitySDK/Assets/Plugins/VrSound.aar
   • UnitySDK/Assets/Plugins/VrLocale.aar
   • UnitySDK/Assets/Plugins/VrGUI.aar
   • UnitySDK/Assets/Plugins/VrAppFramework.aar
   • UnitySDK/Assets/Plugins/vrcontroller-release.aar
4. For Xiaomi headset, Copy the UnitySDK/Assets/MIVR/Scripts/ButtonClick.cs to replace the scipt in Unity For Oculus Go/Gear VR, Copy the UnitySDK/Assets/OVR/Scripts/LaunchNative.cs and attach to any gameobject in the scene
5. Run demo scene
6. For Xiaomi headset, after clicking the button, the app will be transited to the natvie code (Oculus sample VrController). For Oculus Go/Gear VR, the app will be transited to the natvie code (Oculus sample VrController) after launch.
7. We can see that both back/home button are not responding.

Step-by-step Instruction

This section descibe the detailed change we made on the original sample code.

IMPORTANT: It is important to use Oculus Mobile SDK v1.7. Other version may conflict with the Oculus libraries embedded in Xiaomi/Oculus Unity SDK.

Download Oculus Mobile SDK v1.7

Build the native VrController App

This step is optional. Just to verify that the controller does work.

1. Copy the Xiaomi device signature file to VrSample/Native/VrController/Project/Android/assets

2. under VrSample/Native/VrController folder, run Project/Android/build.py

3. Verify that the controller works fine in native app.

Build the Oculus support library

VrApp.java needs to be modified to avoid duplicated intialization on ovrapi

1. Comment out nativeOnCreate() and nativeOnDestroy in VrAppFramework/java/com/oculus/vrappframework/VrApp.java

    public static void onCreate(Activity activity) {
      //nativeOnCreate( activity );
    }

	...
	
    public void onDestroy() {
      if ( mSurfaceHolder != null ) {
          nativeSurfaceDestroyed( mAppPtr );
      }

      //nativeOnDestroy( mAppPtr );
      mAppPtr = 0L;
    }	

2. under VrSample/Native/VrController folder, run Project/Android/build.py

3. Collect following aar files and copy them into Unity project under Assets/Plugins/Android/

• VrAppSupport/VrSound/Libs/Android/aar/Release/VrSound.aar
• VrAppSupport/VrLocale/Libs/Android/aar/Release/VrLocale.aar
• VrAppSupport/VrGUI/Libs/Android/aar/Release/VrGUI.aar
• VrAppFramework/Libs/Android/aar/Release/VrAppFramework.aar

Rebuild VrController into a library instead of an app

1. Change the VrSamples/Native/VrController/Projects/Android/build.gradle, making it a library type

apply plugin: 'com.android.library'
apply from: "${rootProject.projectDir}/VrApp.gradle"

dependencies {
	...
}

android {
  project.archivesBaseName = "vrcontroller"

  defaultConfig {
    // applicationId "com.oculus.vrcontroller"

    // override app plugin abiFilters to test experimental 64-bit support
    externalNativeBuild {
        ndk {
                abiFilters 'armeabi-v7a'//,'arm64-v8a'
        }
        ndkBuild {
                abiFilters 'armeabi-v7a'//,'arm64-v8a'
        }
    }
    
    packagingOptions {
        exclude '**/libvrapi.so'
    }     
  }

  sourceSets {
	...
  }
}

2. Change the VrSamples/Native/VrController/Projects/Android/AndroidManifest.xml , removing extra application related settings and LAUNCHER

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
		package="com.oculus.vrcontroller"
		android:versionCode="1" 
		android:versionName="1.0" 
android:installLocation="auto" >
	...
	<application>
		<meta-data android:name="com.samsung.android.vr.application.mode" android:value="vr_only"/>
		<!-- launchMode is set to singleTask because there should never be multiple copies of the app running -->
		<!-- Theme.Black.NoTitleBar.Fullscreen gives solid black instead of a (bad stereoscopic) gradient on app transition -->
		<activity
				android:name="com.oculus.vrcontroller.MainActivity"
				android:theme="@android:style/Theme.Black.NoTitleBar.Fullscreen"
				android:label="@string/app_name"
				android:launchMode="singleTask"
				android:screenOrientation="landscape"
				android:configChanges="orientation|screenSize|keyboard|keyboardHidden"> 
			<!-- This filter lets the apk show up as a launchable icon -->
			<intent-filter>
				<action android:name="android.intent.action.MAIN" />
				<category android:name="android.intent.category.INFO" />
			</intent-filter>
		</activity>
	</application>
</manifest>

3. Change the VrApp.gradle, commenting out project.android.applicationVariants.all{} section

4. Add a convenient method in VrSamples/Native/VrController/java/com/oculus/vrcontroller/MainActivity.java so it can be launched from Unity

package com.oculus.vrcontroller;

import android.app.Activity;
import android.os.Bundle;
import android.util.Log;
import android.content.Intent;
import com.oculus.vrappframework.VrActivity;

public class MainActivity extends VrActivity {
	
	...
	    
    public static void start(Activity activity) {
        Intent intent = new Intent(activity, MainActivity.class);
        activity.startActivity(intent);
        activity.overridePendingTransition(0, 0);
    }         
}

5. Clean the build by running Project/Android/build.py clean

5. Build the libray by running Project/Android/build.py

6. Copy the VrSamples/Native/VrController/Projects/Android/build/outputs/aar/vrcontroller-release.aar into the Unity project under Assets/Plugins/Android/

Integrate into Unity (Oculus)

1. Use the demo scene GearVrControllerTest

2. Add a script and attach to any gameobject

    public void OnEnable()
    {
		  var vrControllerClass = new AndroidJavaClass ("com.oculus.vrcontroller.MainActivity");

		  AndroidJavaClass unityPlayerClass = new AndroidJavaClass ("com.unity3d.player.UnityPlayer");
		  AndroidJavaObject unityPlayer = unityPlayerClass.GetStatic<AndroidJavaObject> ("currentActivity");

		  vrControllerClass.CallStatic ("start", unityPlayer);
    }

Integrate into Unity (Xiaomi)

1. Use the demo scene 360ViewController

2. Modify the ButtonClick.cs, so when clicking the button the native VrController will be launched

    public void OnClick()
    {
        Debug.Log("**** OnClick.");
        this.transform.GetComponentInChildren<Text>().text = (Random.value * 100).ToString();

		  var vrControllerClass = new AndroidJavaClass ("com.oculus.vrcontroller.MainActivity");

		  AndroidJavaClass unityPlayerClass = new AndroidJavaClass ("com.unity3d.player.UnityPlayer");
		  AndroidJavaObject unityPlayer = unityPlayerClass.GetStatic<AndroidJavaObject> ("currentActivity");

		  vrControllerClass.CallStatic ("start", unityPlayer);
    }