Vuforia / MergeVR Integration

This post outlines the steps required to integrate Vuforia for Digital Eyeware with the MergeVR SDK in Unity. The result of this integration will be an Augmented Reality demo app that can be run in the MergeVR headset on your Android device. It will recognize an image marker and display a 3d object on top of that marker, and allow the user to trigger a virtual button on the object – then enter in VR mode and move around the VR scene using the MergeVR headset capactive input buttons.



Android mobile device

Unity3d – version 4.6.*

Vuforia – Download the core Vuforia unity package – vuforia-unity-5-0-5 (you must be a registered Vuforia developer before the download) and the eyeware samples vuforia-samples-eyewear-unity-5-0-5

MergeVR – download latest Merge SDK Unity package- MergeVR_version_v062




  • Create a new empty Unity Project (4.6.*)
  • Import the Merge SDK Unity package (MergeVR_version_v062.unitypackage)
  • Import the Vuforia core Unity package (vuforia-unity-5-0-5.unitypackage)
  • Import the Vuforia Digital Eyeware sample AR/VR package from the file (arvr-5-0-5.unitypackage)
  • In the Scenes folder find the Scene ‘Vuforia-3-AR-VR’ – Duplicate it (Edit->Duplicate) and rename the new scene ‘DemoVRAR’
  • Open ‘DemoVRAR’ scene.





  • Stop running the scene (if you haven’t already)


  • Find the MergeVR -> Prefabs folder. Drag the MergeCameraController and MergeSDK prefabs into the scene Hierarchy.


  • Expand the MergeCameraController tree.


  • Click on ARCamera under UserHead and view the Inspector Pane. Check (enable) the ‘Bind Alternate Camera’ property.


  • Drag the MergeCameralController root transform to the ARCamera property ‘Central Anchor Point’. Drag MergeCameraRight to ‘Right Camera’ (Vuforia will pop up a box saying ‘add vuforia components’ – click for both right and left cameras), then drag the MergeCameraLeft to ‘Left Camera’


  • On ARCamera property ‘Viewer’ select ‘Other Viewer’ and enter 1 for Viewer ID.


  • Save the Scene – now go ahead and build and run this scene on Android – you should now have a working AR app that can recognize the image stones marker and display the 3d mountain object. If you focus your gaze on the virtual ‘VR’ button for 2 seconds the app will transition you inside the full VR scene where you can look around, to exit the VR scene look straight down and focus on the ‘AR’ button for 2 seconds.


  • We now have a working AR/VR app – we need to make a few modifications to this scene to get it to run best in the MergeVR headset and to let us use the capactive touch buttons on the MergeVR headset to interact with the VR world.


  • The MergeVR headset needs the camera on the right side to work in AR mode with the Android, since the generic Vuforia demo doesn’t support this we have to make a few modifications to the MergeVR code to handle the change.


  • To move the viewport to the correct position when camera is on the right. Open the ‘MergeScreenManager.cs’ script in MergeVR->Scripts. In the function ‘SetViewPortResolutionAndPostion’ replace this line


viewportYpos = viewportBottom;




viewportYpos = viewportBottom+(Screen.height-viewportHeight);


and in the ‘MergeCameraController.cs’ script in MergeVR->Scripts comment out the following lines in the function AndroidGyroTracking



if (Input.deviceOrientation==DeviceOrientation.LandscapeRight || Input.deviceOrientation==DeviceOrientation.LandscapeLeft)

currentOrientation=Input.deviceOrientation; //only change on either full landscape


if (currentOrientation==DeviceOrientation.LandscapeRight) {

androidGyroRotation = new Quaternion (-Y, X, Z, -W);

androidGyroRotation *= Quaternion.Euler(180f,180f,0);







androidGyroRotation = new Quaternion (-Y, X, Z, -W); //default


  • Now build and run the app – the viewports will be aligned correctly and the VR scene will be working as well.


  • Now we need to add interaction with the VR scene (movement in this example) using the MergeVR capactive touch buttons on the headset.


  • Add new script called MergeEyeCustom to the MergeCameraController game object in your scene


using UnityEngine;

using System.Collections;


public class MergeEyeCustom : MonoBehaviour {


public float speed = 1.5f;

public float jumpSpeed = 10.0f;

public float gravity = 10.0f;

public bool allowJump = false;


Vector3 moveDirection =;

float ydirection = 0f;

float xdirection = 0f;


// Use this for initialization

void Start () {




// Update is called once per frame

void Update () {


if (Merge.MSDK.isControllerConnected ()) {

ydirection = Merge.MSDK.getController ().GetAxis (“Vertical”);

xdirection = Merge.MSDK.getController ().GetAxis (“Horizontal”);

} else {

//Use arrow keys in editor – or touch capactive buttons if present in MergeVR headset

if (Input.GetKey (KeyCode.UpArrow) || Merge.MergeInput.GetInput(1))

ydirection = -1;

else if (Input.GetKey (KeyCode.DownArrow) || (!allowJump && Merge.MergeInput.GetInput(0)))

ydirection = 1;


ydirection = 0;


if (Input.GetKey (KeyCode.RightArrow))

xdirection = 1;

else if (Input.GetKey (KeyCode.LeftArrow))

xdirection = -1;


xdirection = 0;



moveDirection = new Vector3 (transform.forward.x * ydirection*speed, 0f, transform.forward.z * ydirection*speed);

moveDirection += new Vector3 (transform.right.x * xdirection*speed, 0f, transform.right.z * xdirection*speed);



transform.position+=moveDirection* Time.deltaTime;





  • Now you can use the left and right MergeVR headset buttons to move around the scene once you are in VR mode.


  • As an exercise you can do the following to polish the example.


remove or modify one of the gaze cursors


optimize rendering performance


add a rigid body or first person controller for more realistic collisions the VR scene

Using Parse SDK with Unity – running on an Android Device


If you are using Parse for your back-end server in a Unity app, and you want to deploy the app to Android, you may run into some issues with the built-in Parse plugin. Specifically (at least in my case with Unity 4.6 and Android KitKat) the Parse query object doesn’t ever return a result.

As a work-around I ended up going with a solution using Unity’s WWW class and the Parse REST API.




private IEnumerator GetParseDataForAndroid () {

	//new WWW object
	WWWForm form = new WWWForm();

	//set headers, not sure why but I had to set twice to get it to work
	Hashtable headers = form.headers.AddAuthorizationHeader("Your-Parse-Application-Id", "javascript-key=Your-Parse-REST-API-Key");


	WWW parseRequest = new WWW("", null, headers);

		//yield until request is done
		yield return parseRequest;

		//request is done, process results
		Debug.Log (" MergeVRBridge parse query eror result is " + parseRequest.error);

		//using simplejson
		var V = JSON.Parse (parseRequest.text);

		JSONArray results = V ["results"].AsArray;

		for (int i=0; i<results.Count; i++) {

			JSONClass jObject = results[i].AsObject;
			//do something interesting with results
			string sTitle = jObject["title"];
			Debug.Log(" yourObject " + sTitle);



Android Studio and Unity3d

If you are building native Android plugins for Unity with Android Studio here are a couple of items that I struggled with. Note that all examples are using Unity 4.6 and Android Studio.

1. Unity Android plugin folder needs a jar file to function – but Android Studio build process does not produce a class jar file.

It turns out that Android Studio actually does create a jar file during the build process and stores it in an intermediate location (on the Mac it is in ‘build/intermediates/bundles/release/’).

Based on suggestions from here I created two new tasks in my gradle file – cleanjar and makejar – after a build I run both and now have the required jar file in my ‘build/outputs/’ folder.

 task clearJar(type: Delete) {
delete ‘build/outputs/MergeVRBridge.jar’
delete ‘build/outputs/AndroidManifest.xml’

task makeJar(type: Copy) {
rename (‘classes.jar’, ‘MergeVRBridge.jar’)

2. If your Android library file requires a context – you can pass it to your lib from Unity.

           androidClass = new AndroidJavaClass(com.mergelabs.MergeVR.MergeVRBridge);

            using(AndroidJavaClass activityClass = new AndroidJavaClass(com.unity3d.player.UnityPlayer)) {
                activityContext = activityClass.GetStatic<AndroidJavaObject(currentActivity);

and in your Android Java clase you’ll have the appropriate function

private static Context mContext;

 static public void setContext(Context context) {

mContext = context;

3. You need bluetooth permissions set in your Android plugins manifest file.

If you just copy and paste the manifest file from your Android Studio build directory to the Unity Android plugin directory you will see compile and build errors. It appears in Unity 4.6 that if you place a manifest file in the Android plugin directory it overrides the Unity created manifest file for the entire app.

The best solution is to find the Unity generated manifest file, copy it to a temp directory and modify by adding any permissions you need (in my case bluetoth related), then add to the Android plugins folder – Unity will use this manifest file as the default and all will be well.

<?xml version=”1.0″ encoding=”utf-8″?>
<manifest xmlns:android=”; package=”com.merge.demo” android:versionName=”1.0″ android:versionCode=”1″ android:installLocation=”preferExternal”>

<uses-permission android:name=”android.permission.BLUETOOTH”/>
<uses-permission android:name=”android.permission.BLUETOOTH_ADMIN”/>
<uses-feature android:name=”android.hardware.bluetooth_le” android:required=”true”/>

<supports-screens android:smallScreens=”true” android:normalScreens=”true” android:largeScreens=”true” android:xlargeScreens=”true” android:anyDensity=”true” />

<application android:theme=”@android:style/Theme.NoTitleBar” android:icon=”@drawable/app_icon” android:label=”@string/app_name” android:debuggable=”false”>
<activity android:name=”com.unity3d.player.UnityPlayerNativeActivity” android:label=”@string/app_name” android:screenOrientation=”sensorLandscape” android:launchMode=”singleTask” android:configChanges=”mcc|mnc|locale|touchscreen|keyboard|keyboardHidden|navigation|orientation|screenLayout|uiMode|screenSize|smallestScreenSize|fontScale”>
<action android:name=”android.intent.action.MAIN” />
<category android:name=”android.intent.category.LAUNCHER” />
<category android:name=”android.intent.category.LEANBACK_LAUNCHER” />
<meta-data android:name=”unityplayer.UnityActivity” android:value=”true” />
<meta-data android:name=”unityplayer.ForwardNativeEventsToDalvik” android:value=”false” />
<uses-sdk android:minSdkVersion=”18″ android:targetSdkVersion=”21″ />
<uses-feature android:glEsVersion=”0x00020000″ />
<uses-feature android:name=”android.hardware.touchscreen” android:required=”false” />
<uses-feature android:name=”android.hardware.touchscreen.multitouch” android:required=”false” />
<uses-feature android:name=”android.hardware.touchscreen.multitouch.distinct” android:required=”false” />
<uses-permission android:name=”android.permission.WAKE_LOCK” />