Version: 2020.3
Language : English
Getting started with iOS development

Integrating Unity into native iOS applications

This page describes how to integrate the Unity Runtime Library into iOSApple’s mobile operating system. More info
See in Glossary
native applications with the Unity as a Library feature.

You can use this feature to include Unity-powered features, such as 3D/2D Real-Time RenderingThe process of drawing graphics to the screen (or to a render texture). By default, the main camera in Unity renders its view to the screen. More info
See in Glossary
, ARAugmented Reality More info
See in Glossary
Experience, 3D model interaction, or 2D mini-games, in your native application. The Unity Runtime Library exposes controls to manage when and how to load, activate, and unload content in your native application.

How it works

To use Unity as a Library for iOS, first build your Xcode project as usual from Unity (for more information, see Build settings for iOS).

Every Unity iOS Xcode project has the following structure:

  • A library part in the UnityFramework target that includes the source, plug-insA set of code created outside of Unity that creates functionality in Unity. There are two kinds of plug-ins you can use in Unity: Managed plug-ins (managed .NET assemblies created with tools like Visual Studio) and Native plug-ins (platform-specific native code libraries). More info
    See in Glossary
    , and dependent frameworks. It also produces a UnityFramework.framework file.
  • A thin launcher part in the Unity-iPhone target that includes app representation data and runs the library. The Unity-iPhone target has a single dependency on the UnityFramework target.

To integrate Unity into another Xcode project, you need to combine both Xcode projects (the native one and the one Unity generates) into a single Xcode workspace, and add the UnityFramework.framework file to the Embedded Binaries section of the Application target for the native Xcode project. Once you do this, you can use the UnityFramework class to control the Unity runtime.

This repository contains example Projects and plug-ins that demonstrate how to integrate Unity into an Xcode project, along with further documentation.

UnityFramework class

You can control the Unity runtime through an instance of the UnityFramework Objective-C class, which is a principal class of UnityFramework.framework:

Method Description
+ (UnityFramework*)getInstance; Singleton class method that returns an instance to UnityFramework.
- (UnityAppController*)appController; Returns the UnityAppController subclass of UIApplicationDelegate. This is the root Unity class on the native side, and can access the app’s View-related objects, such as UIView, UIViewControllers, CADisplayLink, or DisplayConnection.
- (void)setDataBundleId:(const char*)bundleId; Sets the Bundle where the Unity runtime should look for the Data folder. For more information, see documentation on the Data folder. Call this method before calling runUIApplicationMainWithArgc or runEmbeddedWithArgc.
- (void)runUIApplicationMainWithArgc:(int)argc argv:(char*[])argv; The default way to run Unity from the main method where there are no other Views.
- (void)runEmbeddedWithArgc:(int)argc argv:(char*[])argv appLaunchOpts:(NSDictionary*)appLaunchOpts; Call this method when you need to run Unity when other Views exist.
- (void)unloadApplication; Call this to unload Unity and receive a callback to UnityFrameworkListener after the unload completes. Unity will release most of the memory it occupies, but not all of it. You will be able to run Unity again.
- (void)registerFrameworkListener:(id<UnityFrameworkListener>)obj; Register the listener object that receives callbacks of UnityFramework lifecycle-related events.
- (void)unregisterFrameworkListener:(id<UnityFrameworkListener>)obj; Unregister a listener object.
- (void)showUnityWindow; Call this method while a non-Unity View is showing to also show a Unity View that’s already running.
- (void)pause:(bool)pause; Pause Unity.
- (void)setExecuteHeader:(const MachHeader*)header; You must call this before running Unity in order for CrashReporter to work properly.
- (void)sendMessageToGOWithName:(const char*)goName functionName:(const char*)name message:(const char*)msg; This method is a proxy to UnitySendMessage. It finds a game object by name and calls functionName with a single-string message parameter.
(void)quitApplication:(int)exitCode; Call this to unload Unity completely and receive a callback to UnityFrameworkListener when Unity quits. Unity will release all memory.

Note: You won’t be able to run Unity again in the same process after this call. You can set quitHandler on AppController to override the default process kill.


Unity doesn’t control the runtime life cycle, so Unity as a Library might not work for all possible use cases. Known limitations include:

  • Unity as a Library only supports full-screen rendering, and doesn’t support rendering on part of the screen.
  • You can’t load more than one instance of the Unity runtime.
  • You might need to adapt third-party plug-ins (both native and managed) to work with the Unity runtime.

  • Unity as a Library for iOS added in 2019.3.NewIn20193
Getting started with iOS development