Crash when embedding Unity into iOS

Questions & Answers
1

I’m trying to bring a Unity scene into our existing iOS application. I exported the Xcode project and modified the UnityAppController to keep it from taking over the app flow. Then on a button press I try to initialize the Unity stuff. Here’s what I have:

ViewController

-(IBAction)clikedStart:(id)sender
{
    _controller = [UnityController instance];
    [_controller startUnity];
}

UnityController

+(UnityController*)instance
{
    static UnityController* instance = nil;
    if(instance == nil)
    {
        UnityInitTrampoline();
        RegisterMonoModules();
        instance = [[UnityController alloc] init];
        [instance setUpDisplay];
    }
    return instance;
}

-(void)setUpDisplay
{
    if ([UIDevice currentDevice].generatesDeviceOrientationNotifications == NO)
        [[UIDevice currentDevice]beginGeneratingDeviceOrientationNotifications];
    
    [DisplayManager Initialize];
    
    _mainDisplay	= [[[DisplayManager Instance] mainDisplay] createView:YES showRightAway:NO];
    _window			= _mainDisplay->window;
    
    [KeyboardDelegate Initialize];
    
    [self createViewHierarchy];
    UnityInitApplicationNoGraphics([[[NSBundle mainBundle] bundlePath]UTF8String]);
}

-(void)startUnity
{
    printf_console("-> Start Unity

");

	UnityInitApplicationGraphics();

	// we make sure that first level gets correct display list and orientation
	[[DisplayManager Instance] updateDisplayListInUnity];
	[self updateOrientationFromController:[SplashScreenController Instance]];

	UnityLoadApplication();
	Profiler_InitProfiler();

	[self showGameUI];
	[self createDisplayLink];
}

-(void)resumeUnity
{
    printf_console("-> Resume Unity

");

    if(_unityAppReady)
    {
        if(_didResignActive)
            UnityPause(false);
    }
    else
    {
        [self performSelector:@selector(startUnity) withObject:nil afterDelay:0];
    }
    
    [GetController().unityView recreateGLESSurfaceIfNeeded];
    
    _didResignActive = false;
}

-(void)pauseUnity
{
    printf_console("-> Pause Unity

");

    if(_unityAppReady)
    {
        UnityPause(true);
        
        extern void UnityStopVideoIfPlaying();
        UnityStopVideoIfPlaying();
        
        // Force player to do one more frame, so scripts get a chance to render custom screen for
        // minimized app in task manager.
        UnityForcedPlayerLoop();
        [self repaintDisplayLink];
    }
    
    _didResignActive = true;
}

-(void)stopUnity
{
    printf_console("-> Stop Unity

");

    Profiler_UninitProfiler();
    UnityCleanup();
}

-(void)dealloc
{
    extern void SensorsCleanup();
    SensorsCleanup();
    
    [self releaseViewHierarchy];
    [super dealloc];
}

But it’s crashing down in UnityInitApplicationNoGraphics([[[NSBundle mainBundle] bundlePath]UTF8String]); with this stack

#0	0x00b9488c in std::_Rb_tree<int, std::pair<int const, Object::RTTI>, std::_Select1st<std::pair<int const, Object::RTTI> >, std::less<int>, stl_allocator<std::pair<int const, Object::RTTI>, (MemLabelIdentifier)1, 16> >::_M_begin() [inlined] at /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS7.0.sdk/usr/include/c++/4.2.1/bits/stl_tree.h:476
#1	0x00b9488c in std::_Rb_tree<int, std::pair<int const, Object::RTTI>, std::_Select1st<std::pair<int const, Object::RTTI> >, std::less<int>, stl_allocator<std::pair<int const, Object::RTTI>, (MemLabelIdentifier)1, 16> >::find(int const&) [inlined] at /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS7.0.sdk/usr/include/c++/4.2.1/bits/stl_tree.h:1373
#2	0x00b94874 in std::map<int, Object::RTTI, std::less<int>, stl_allocator<std::pair<int const, Object::RTTI>, (MemLabelIdentifier)1, 16> >::find(int const&) [inlined] at /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS7.0.sdk/usr/include/c++/4.2.1/bits/stl_map.h:542
#3	0x00b94874 in Object::ClassIDToRTTI(int) at /Applications/buildAgent/work/d63dfc6385190b60/Runtime/BaseClasses/BaseObject.cpp:828
#4	0x00b9b88c in Unity::GameObject::RegisterClass() at /Applications/buildAgent/work/d63dfc6385190b60/Runtime/BaseClasses/GameObject.cpp:1374
#5	0x00b94f48 in Object::InitializeAllClasses() at /Applications/buildAgent/work/d63dfc6385190b60/Runtime/BaseClasses/BaseObject.cpp:903
#6	0x00cda400 in InitializeEngineNoGraphics() at /Applications/buildAgent/work/d63dfc6385190b60/Runtime/Misc/SaveAndLoadHelper.cpp:210
#7	0x00ccb594 in PlayerInitEngineNoGraphics(std::string const&, std::string const&) at /Applications/buildAgent/work/d63dfc6385190b60/Runtime/Misc/Player.cpp:711
#8	0x00ac6170 in UnityInitApplicationNoGraphics at /Applications/buildAgent/work/d63dfc6385190b60/PlatformDependent/iPhonePlayer/LibEntryPoint.mm:188

Specifically on this line of the assembly 0xbc288c: ldr r3, [r1]

Has anyone else managed to do this successfully? What am I missing?

2

Seems like the reverse integration doesn’t works & the other way does. When I tried porting unity libs & settings to my iOS project I saw a crash (the app exits without a stack trace) after internal call to

InitializeMonoFromMain(std::vector<std::string, std::allocator<std::string> > const&, std::string, int, char const**, bool) + 524 at MonoManager.cpp:2078
0x142d9a4:  movw   r0, #0xef40
0x142d9a8:  mov    r1, r4
0x142d9ac:  movt   r0, #0xae
0x142d9b0:  ldr    r0, [pc, r0]
0x142d9b4:  bl     0x142df08                 ; std::vector<std::string, std::allocator<std::string> >::operator=(std::vector<std::string, std::allocator<std::string> > const&) at stl_vector.h:283
0x142d9b8:  mov    r0, #0x0
0x142d9bc:  mov    r4, #0x0
0x142d9c0:  bl     0x18d9724                 ; mono_config_parse
0x142d9c4:  mov    r0, #0x0
0x142d9c8:  bl     0x1841bd4                 ; mono_parse_default_optimizations
0x142d9cc:  mov    r1, r0
0x142d9d0:  mov    r0, #0x0
0x142d9d4:  bl     0x183ad0c                 ; mono_set_defaults
0x142d9d8:  movw   r0, #0x2964

But if I add my classes to the unity editor’s auto generated project, it works fine.

3

Has someone found any solution to be able to embed Unity scene into an existing iOS project?

It worked for me with the latest version of Unity, but when I updated to Unity 2017 it started crushing in the same line as @The13Beast:

UnityInitApplicationNoGraphics([[[NSBundle mainBundle] bundlePath]UTF8String]);

Thank you!