Add Unity3D in a native iOS application


The problem

For a project I need to implement an augmented reality feature inside a native iOS application.  We chose to go with Unity3D and Vuforia to do the augmented reality bit, as it’s free and lots of people are saying it’s the best solution. The only problem when working with Unity3D is that the exported iOS project is not easy to implement in an existing project as we only need Unity3D for 2 views inside a project with some dozen other native UIViews. I started looking around on different blogs and fora and noticed there were a lot of people asking the same question.  Everybody has different approaches, some worked, some didn’t.  A lot of these solutions worked under Unity 3, but are broke in Unity 4. So with this blogpost I hope to help some people out who are having troubles under Unity 4+ and Xcode 5+. I’ve put the Xcode  and Unity3D project on GitHub, so feel free to download it, copy and/or alter it to fit your needs!  Hope it can save you some hours I’ve lost while trying to get it to work 🙂

tl;dr how to add Unity3D in a native iOS application

Read it … bitch 😉

The Unity3D part

Well … if you want to use Unity3D in your project you’ll first have to create the Unity3D part! Open up Unity3D and create a new project.  I’ll call mine ‘NativeUnity’. When Unity3D creates a new project, you get an empty scene.  Go to File > Save to save the scene.  I’ll call it ‘scene1’. Go nuts and put some content in it so we can actually see something. Add Unity3D in a native iOS application Ok, now let’s build this so it can run on an iOS device and we know for sure that everything works correctly. Go to File > Build Settings. Click on ‘Add Current’ to add the current scene to your build. Add Unity3D in a native iOS application

Next choose iOS as your platform and click on ‘Player Settings’ at the bottom of the dialog.  This will open the ‘Inspector panel’ and let you set all the settings for the Xcode project.  In my case I will change the following settings (but they can -and probably will- be different of yours).

  • Default orientation : Landscape right
  • Bundle identifier: be.thenerd.unityNative
  • Target device: iPad
  • Target iOS version: 7.0

Now click on ‘Build & Run’ in the Build Settings dialog. Unity will ask you where to put the Xcode project. I will put it in a folder called ‘ios-builds’ outside of my Unity project and call it ‘unity-native-ipad’. Add Unity3D in a native iOS application Click ‘Save’ and let Unity sprinkle its magic and create the Xcode project (this can take some time).  If all goes well, your app will boot on your device and you should see the scene you’ve made. Add Unity3D in a native iOS application Ok … so that’s that, but how can we now use this view as a part of normal native app instead of a Unity app. First we’ll need to override the ‘UnityAppController’ class with our own version. To do this we need to create in the Assets folder of our Unity project a ‘Plugins’ folder and inside this folder add a ‘iOS’ folder. So your structure needs to look like this:

  • Assets
    • Plugins
      • iOS

Make sure you name everything correct otherwise it will not work!  Unity checks if these folders exists and copy all their contents to the Xcode project. You can read more about this if you are interested on this page at the ‘Automated plugin integration’ section. Now you need to create a file in the iOS folder. I’ll call mine, but you can call yours whatever you want it to be.  Now do another build in Unity, and you should see the file appear in your Xcode project in the Libraries folder.

Add Unity3D in a native iOS application

Now the important part: don’t edit the file in this Xcode project, because it will be overwritten every time you do a new Unity build! Instead go to Unity and double-click on the file (it will also open in Xcode). Now we can override Unity’s AppController class with the following code.

Especially the IMPL_APP_CONTROLLER_SUBCLASS bit is important, as this is the way to set a custom app controller!  What happens is IMPL_APP_CONTROLLER_SUBCLASS is defined in UnityAppController.h and this will set our AppController as the one to be loaded! Now in the ‘createViewHierarchyImpl’ methode we can set our own view hierarchy. So for this example I’ll create a UINavigationController which has 3 view controllers.

  1. A hello view controller
  2. A unity view controller with our scene
  3. A goodbye view controller

First we’ll need to create the different view controllers in our Unity Xcode project. So open that Xcode project.  To keep the Unity code (which resides in the ‘Classes’) folder separated  from our code I create a group called ‘My_Projectname’ (of course you can change this :)). In this folder I’ll create the 3 view controllers. Make sure to rename your CoolUnitySceneViewController.m file to! This is because we will need to run some Objective-C++ code in that file!

  1. HelloViewController (subclass UIViewController)
  2. CoolUnitySceneViewController (subclass UIViewController)
  3. GoodByeViewController (subclass UIViewController)

So your structure should look something like this

. Add Unity3D in a native iOS application

In HelloViewController.m we’ll add a button to go to the next view controller in the viewDidLoad: method.

Now go to the file in the same project (so the Unity project).  Because of the code hinting it’s easier to write the code here at this point and then just copy it over to the actual file in the Unity plugins folder (but don’t build in the meanwhile or it will be overwritten!). In the ‘createViewHierarchyImpl’ method we’ll first set the ‘_rootController’ property to an instance of UIViewController and set the ‘_rootView’ property to an empty view. Then set the _rootView property as the view of the _rootController.

Now we can create the HelloViewController (don’t forget to import the header file at the top).

We want to push this onto an UINavigationController object, but we first need to create it. Create a private property for the navigation controller .

Let’s create the navigation controller and set the hello view controller as the root view controller.  Then we can add the navigation controller’s view as a subview of the _rootView.

Ok, that’s it. Now copy the contents of this file to the TNAppController file in your Unity project. Now go back to your Unity project and hit ⌘+b to build again.  The TNAppController file will now be overwritten, but the files in our ‘My_ProjectName’ will be untouched! If all goes well, you should see the following. Add Unity3D in a native iOS application Now the part you have been waiting for  (I guess …), let’s hook up a view controller which loads the Unity3D scene. Go to your CoolUnitySceneViewController.h file and import the following headers.

Now go to the implementation file ( and locate the viewDidLoad: method and add this bit of code.

That’s it … we grab the unityView property of the AppController (which we get via the utility method ‘GetAppController’ defined in UnityAppController.h and add it to our view. Then we add a button which lays on top of the unity view.  When we click on this button we execute the goToLastScene method and there we will load the last view controller (don’t forget to import the view controller at the top of the file).

In the viewDidLoad: method of GoodByeViewController you can now add the following code.

Now run the app again and you should see the following screens if you click on the buttons. Add Unity3D in a native iOS application Add Unity3D in a native iOS application

I hope this will help some of you out to add Unity3D in a native iOS application!  If you have any remarks, please put them in the comments!  I’ve only started working with Unity since yesterday, so it could be there is an easier method, but I kinda like this one already!

I’ve put all the code on GitHub, so you can check out the project.  For the iPhone project I only uploaded the files I’ve mentioned above, because otherwise the folder was 450MB big!

Reference material

  • Pingback: Call methods on Unity3D straight from your Objective-C code | the-nerd()

  • Pingback: Sandbox Unity app in existing iOS app | the-nerd()

  • Landon donovan

    Very helpful. Any luck passing messaging in or out of unity?

  • yeah for messaging from unity to objc, use a wrapper class. to message from objc to unity you can use my other blog post (

  • Juanfran

    This don´t work in iOS8….

    • frederik_jacques

      Hm it should work as I just did it this week. I’ll try to make a video tutorial this weekend showing the different steps!

      • Juanfran

        I think that the problem is “bounds”, in this line:

        _rootView = [[UIView alloc] initWithFrame:[[UIScreen mainScreen] bounds]];

        • fraker

          in IOS8 createViewHierarchyImpl method is deprecated,you can override createUI method
          – (void)createUI{
          _rootController = [[UIViewController alloc] init];
          _rootView = [[UIView alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
          _rootView.backgroundColor = [UIColor redColor];
          _rootController.view = _rootView;

          HelloViewController *helloVC = [[HelloViewController alloc] initWithNibName:nil bundle:nil];

          self.navController = [[UINavigationController alloc] initWithRootViewController:helloVC];

          [_rootView addSubview:self.navController.view];
          [_window addSubview:_rootView];
          _window.rootViewController = _rootController;
          [_window bringSubviewToFront:_rootView];
          [_window makeKeyAndVisible];
          this method is declared in file UnityAppController+ViewHandling.h

          • fraker

            and thank you very much for author, help me a lots

  • Jack

    hi, Frederik,

    so great to see this blog, awesome. I have two questions, first, how to add gesture to the unity view in native app for rotating the 3D model? second, if I have several 3d models, each one is a scene in unity, How to import them together into one native app and load them respectively in native app?

    Thanks in advance,

  • Riccardo

    Great Job !!

    thanks so much!!!


  • iManuQiao

    Man you kick butt. I’ve found solution of this topic for over a week. As you said, ‘A lot of these solutions worked under Unity 3, but are broke in Unity 4’. Today, Problem ends here.

    I tested with Unity 4.5.5f1, XCode 6.1 (6A1052d), iOS 8 simulator Version 8.1 (550.3). It works perfectly.

    Additionally, interface builder works OK. If you drop everything but unity view in CoolUnitySceneViewController, you can resize the frame of the view of that controller, add to any other view as subview. It reacts well.

  • Salvador

    Hello, thanks for the tutorial.

    Now I have a little problem. I doesn’t know how to switch from NavViewController to ViewController.

    The project I have needs the VuforiaAR System, I just follow your tutorial and it works with Vuforia and your example. I add my original project and it have ViewController instead of NavViewController. I just doesn’t know where to make this switch and add my project instead of your NavView.

    I hope you can helpme a little.
    Sorry if my english is so rude.

  • Matias

    Hello great tutorial very useful!
    Is there any way to remove the top navigation bar (the one with the back button)?


    • Ben MacKinnon

      In the custom file under the line:
      self.navController = [[UINavigationController alloc] initWithRootViewController:helloVC];
      add the line:
      self.navController.navigationBarHidden = YES;

  • Zergl

    thank for tutorial

    i try your tutorial but i can’t.

    this tutorial is so hard to me. but i should do this.

    can you send me source code??

    i just need your help

  • arai

    hi, thanks for the tutorial, manage to get it work, I’m getting close to what I want but I’m stuck at getting the IOS View to only appear when I tap on a button in its more like the other way round. Instead of having the IOS View shown at first, I want Unity View to show first, then hide Unity when I tap on button to show IOS View..

  • huk

    hi, Frederik,

    Thank you for nice stuff. I have some problems.
    – Exported your unity project for ios
    – Copied and pasted your other files which are HelloViewController etc.
    – and tried to run in xcode
    But in file and line of
    _rootController = [[UnityDefaultViewController alloc] init];
    use of undeclared identifier “UnityDefaultViewController” exception

    Can you help me please ?

    • frederik_jacques

      I’ve sent the source files to your email address via wetransfer 🙂

      • huk

        Hi frederik,

        Thank you for your quick response. I will try with your source at night (about 5 hours later ). I hope that help to me.

        Thank you my friend.

        • Amt

          Thank you for tutorial,
          But also I have some problems like
          – Use of undeclared identifier ‘UnityDefaultViewController’
          – CoolUnitySceneViewController.h:12:10: ‘UnityAppController+ViewHandling.h’ file not found

          I’m not unity developer, so can you please share the source code, or help to solve problem ?

          Thank you

  • jayjayesh

    hi, Frederik
    thank for tutorial

    i have one question, can i pass an array of string from HelloViewController.m to ‘unity view’ ?

  • mad

    good artcile !! but Image is not visible! 🙁

  • Oliver

    Hi Frederik,

    I followed your great tutorial: thank you for this!

    I got a little problem: for the file “UnityViewControllerBase.h”:
    /Classes/UI/UnityViewControllerBase.h:52:8: Expected identifier or ‘(‘
    /Classes/UI/UnityViewControllerBase.h:53:8: Expected identifier or ‘(‘

    How could this be? I copied the scripts from the Git Repo.



    • Oliver

      I’m using Unity 5.0.0b18, if this is of any importance.

      • frederik_jacques

        Hi Oliver,

        I haven’t tested with Unity 5 beta yet.
        Probably they will have changed some stuff in the generated IOS builds from Unity.
        When the final is out, I will post an update if I found out how to embed Unity inside a native IOS app!

        • Oliver

          Hi Frederik,

          I fixed it:



          • charles

            What was your fix? I am having the same issue with a Unity 5 build.


          • Ben MacKinnon

            I’ve also hit this problem, what was your fix?

          • Ben MacKinnon

            Incase anyone else is looking for it here, I fixed the above issue by changing those bottom two extern “C” methods to this:

            // this is helper to add proper rotation handling methods depending on ios version
            //FIX HERE
            #ifdef __cplusplus
            extern “C” {
            void AddViewControllerRotationHandling(Class class_, IMP willRotateToInterfaceOrientation, IMP didRotateFromInterfaceOrientation, IMP viewWillTransitionToSize);
            #ifdef __cplusplus

            #ifdef __cplusplus
            extern “C” {
            void AddViewControllerDefaultRotationHandling(Class class_);
            #ifdef __cplusplus

  • Jonas


    The xcode project file is missing… Or am I missing something… 🙂


  • Ksenia

    Help me please.
    My project doesn’t go in TNAppController. Why is it happening?
    (I create new file in my project and copy code)

  • vamshi


    We are also trying to implement IOS native UI with Unity3d 4.6.2 using this link.

    We done the same with Vuforia 3.0.7 SDK & Unity3d 4.6.2 , working fine.

    But when we try with Vuforia 4.0 SDK beta and unity3d 4.6.2, its not working. IOS native buttons are displayed but Vuforia Camera is not initialized. Showing black screen. How to solve this one?

    Can anyone tried?

    It would be great if i get suggestions.

    • frederik_jacques

      I got it working with Unity 4.6.2 & latest beta of Vuforia (4.0.19 or something).
      Unity now generates a custom class which gets loaded VuforiaNativeRendererController.

      In this one you’ll have to do all your initialization of your own code.

      • Lee

        Would you be willing to sell the project with 4.6.2 with vuforia 4 working?

        Or do any side work implementing this type of thing, really struggling with the new il2cpp project merging into my old ios project.

        email me if you do either lol

      • Ben MacKinnon

        Are you saying that we need to move the code from the TNAppController into the new VuforiaNativeRenderController? I’ve hit this issue with an app that need to be updated for the app store and we’ve needed to obviously add 64bit support, so project was updated to Vuforia 4.2 and Unity 4.6.5

  • Hi,
    as unity 5 was yesterday released i tried the whole day to implement it (as i got it working with 4.6.x – things changed again).

    I wrote a tutorial about it (hope it helps someone). If you want – the-nerd- you are allowed to take out the parts for your tutorial to update it 🙂 As you helped me a lot in the past with yours – this is just fair 🙂

  • charles

    Had this working with Unity 4.6, but just updated to 5 and getting the
    Expected identifier or ‘(‘ error.

    • charles

      Also, if I remove the My_projectName folder from the project the error goes away.

  • Paul

    I’m trying to get this to work with a storyboard that has a navigation controller as the initial view controller.

    Can you advise as no joy yet…


  • roberto

    great tutorial!

    i follow this tutorial with unity 4.6 and work fine!
    but now i tried this tutorial with unity 5.0.1 and doen’t work…
    i changed
    but nothing…

    there is a solution for this problem?

    thanks a lot

  • Deepak

    In this tutorial says how to add other project add to unity . Is there any way to add unity xcode project add to another existing project?

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  • ravoori varan

    Hello, Thanks for the tutorial which explains how to integrate unity in an existing xcode project. Currently i created a unity project and trying to create in .mm file under Assets->Plugins->iOS in unity project. but when i tap on create button, i count find a option that allows me to create a .mm file??? could you please tell me how to create a .mm file in unity project and use it in my xcode project

    • Nike Kovalyonok

      Just go to Plugins folder in your Unity project (use Finder) and create txt file (or cope any text file), then change extension to .mm and open it by Xcode.

  • Azad Shekmydeen

    Can you tell me how to quit or unload the unity from iOS native app?

    • Openxcell Kalpesh

      have you found any solution?

  • Carlos Pallares

    Hi, i´m having an issue and maybe was because in the build settings i put it for iPad and iPhone

    Help please!

  • Openxcell Kalpesh

    i have an issue in relaunching Unity-App-Code from Core-IOS-App-Code, please help me to make it dynamically working. As i have many other modules so here i am loading Unity-Code when required to launch it, but failed to release after use of it.