最近遇到一个识别图像后显示3D模型的需求，权衡再三选择了国内的easyAR SDK。Unity建模完成后，导出相应的iOS工程，由于Unity模块在我的工程中是作为一个功能模块存在的，因此需要将导出的Unity iOS工程集成到原生工程中。集成过程稍显复杂，也躺过一些坑，此处做一个记录以铭心志。另外关于Unity建模不是本文要探讨的内容，本人也纯属Unity小白，瞎折腾一番后模型勉强符合预期，惭愧~

【Unity版本】2017.1.1f1 【Xcode版本】8.3.3

导出Unity iOS工程

Unity模型搭建好之后，需要导出iOS工程。相关配置如下:

0

由于是easyAR unity工程，务必保证Bundle ID与easyAR中注册的一致。配置完成后点击build，即可导出unity iOS工程。本例中工程文件结构如下，其中 unity_general 为unity导出的iOS工程，zhb_general 为目标iOS工程。

unity文件引用

在目标iOS工程里引用unity iOS工程中的文件，主要就是三个目录，Classes，Libraries，Data。这里需要注意的是，Classes和Libraries目录作为Group引用，切记不要勾选copy，而Data目录不需要参与编译，作为folder引用进来即可。本例中统一引用到Unity group下，文件结构如下：

工程配置

• 关闭bitcode。新版的Unity已经支持Bitcode但EasyAR并不支持，不关闭无法正常编译。

  
  

• 修改Linking -> Other Linker Flags选项，添加参数 -weak_framework CoreMotion -weak-lSystem。

• 修改头文件搜索目录

• 修改库搜索目录

• 修改LLVM - Custom Complier Flags -> Other C Flags选项，添加两个参数： -DINIT_SCRIPTING_BACKEND=1 和 -DRUNTIME_IL2CPP=1。

• 修改LLVM - Language -> C Language Dialect选项，选择C99。

7

• 修改LLVM - Language - C++ -> C++ Language Dialect选项，选择 C++11。

• 添加三项自定义设置
  • MTL_ENABLE_DEBUG_INFO -> NO
  • UNITY_RUNTIME_VERSION -> 2017.1.1f1（当前你的Unity3d版本号，请自行替换）
  • UNITY_SCRIPTING_BACKEND -> il2cpp

• 新建一个PCH文件，并修改Precompile Prefix Header为YES，关联pch文件路径。此处新建文件名为 PrefixHeader.pch。

添加工程依赖

修改代码

1. 找到unity工程的pch文件，完整复制内容到之前建好的PrefixHeader.pch文件中。

2. 找到unity工程的main.m文件，复制其内容到新建工程的main.m文件中，将main.m修改为main.mm允许C++混编，并修改AppDelegate为工程代理类。

   #include "RegisterMonoModules.h"
   #include "RegisterFeatures.h"
   #include <csignal>
   
   // Hack to work around iOS SDK 4.3 linker problem
   // we need at least one __TEXT, __const section entry in main application .o files
   // to get this section emitted at right time and so avoid LC_ENCRYPTION_INFO size miscalculation
   static const int constsection = 0;
   
   void UnityInitTrampoline();
   
   // WARNING: this MUST be c decl (NSString ctor will be called after +load, so we cant really change its value)
   const char* AppControllerClassName = "UnityAppController";
   
   int main(int argc, char* argv[])
   {
       UnityInitStartupTime();
       @autoreleasepool
       {
           UnityInitTrampoline();
           UnityInitRuntime(argc, argv);
           
           RegisterMonoModules();
           NSLog(@"-> registered mono modules %p\n", &constsection);
           RegisterFeatures();
           
           // iOS terminates open sockets when an application enters background mode.
           // The next write to any of such socket causes SIGPIPE signal being raised,
           // even if the request has been done from scripting side. This disables the
           // signal and allows Mono to throw a proper C# exception.
           std::signal(SIGPIPE, SIG_IGN);
           UIApplicationMain(argc, argv, nil, [NSString stringWithUTF8String:"AppDelegate"]);
       }
       return 0;
   }
   
   #if TARGET_IPHONE_SIMULATOR && TARGET_TVOS_SIMULATOR
   
   #include <pthread.h>
   
   extern "C" int pthread_cond_init$UNIX2003(pthread_cond_t *cond, const pthread_condattr_t *attr)
   { return pthread_cond_init(cond, attr); }
   extern "C" int pthread_cond_destroy$UNIX2003(pthread_cond_t *cond)
   { return pthread_cond_destroy(cond); }
   extern "C" int pthread_cond_wait$UNIX2003(pthread_cond_t *cond, pthread_mutex_t *mutex)
   { return pthread_cond_wait(cond, mutex); }
   extern "C" int pthread_cond_timedwait$UNIX2003(pthread_cond_t *cond, pthread_mutex_t *mutex,
                                                  const struct timespec *abstime)
   { return pthread_cond_timedwait(cond, mutex, abstime); }
   
   #endif // TARGET_IPHONE_SIMULATOR && TARGET_TVOS_SIMULATOR
   

   同时在Build Phases -> Compier Sources 中删掉unity工程中的main.mm，只编译目标工程的main.mm。

3. 修改UnityAppController.h，将其中的内联函数GetAppController()修改如下：

   #import "AppDelegate.h"
   inline UnityAppController* GetAppController()
   {
       AppDelegate *delegate = (AppDelegate *)[UIApplication sharedApplication].delegate;
       return delegate.unityController;
   //    return (UnityAppController*)[UIApplication sharedApplication].delegate;
   }
   

4. 新建EasyARAppController.h，因为原本的EasyARAppController是没有头文件的，是通过OC运行时初始化的，为了方便在代码中初始化和使用，单独建立它的头文件，并调整一下EasyARAppController.mm文件。

   //EasyARAppController.h 
   #import "UnityAppController.h"
   @interface EasyARAppController : UnityAppController
   @end
   
   //EasyARAppController.mm
   #import <UIKit/UIKit.h>
   #import "EasyARAppController.h"
   
   extern "C" void ezarUnitySetGraphicsDevice(void* device, int deviceType, int eventType);
   extern "C" void ezarUnityRenderEvent(int marker);
   
   @interface EasyARAppController ()
   - (void)shouldAttachRenderDelegate;
   @end
   
   @implementation EasyARAppController
   - (void)shouldAttachRenderDelegate;
   {
       UnityRegisterRenderingPlugin(&ezarUnitySetGraphicsDevice, &ezarUnityRenderEvent);
   }
   @end
   
   IMPL_APP_CONTROLLER_SUBCLASS(EasyARAppController)
   

5. 创建MyARAppController，继承自EasyARAppController，作为后续开发的交互controller。

   //MyARAppController.h
   #import "EasyARAppController.h"
   @interface MyARAppController : EasyARAppController
   @end
   
   //MyARAppController.mm
   #import "MyARAppController.h"
   #import "AppDelegate.h"
   #import "UnityViewControllerListener.h"
   
   #define BackButtonTag 10000
   
   extern "C" {
       void backToNative(){
           AppDelegate* delegate =  (AppDelegate *)[UIApplication sharedApplication].delegate;
           [delegate hideUnityWindow];
       }
   }
   
   @interface MyARAppController ()
   @property (nonatomic, strong) UIButton *backButton;
   @end
   
   @implementation MyARAppController
   
   - (instancetype)init{
       self = [super init];
       if (self) {
           [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(viewDidLoad) name:kUnityViewWillAppear object:self.rootViewController];
       }
       return self;
   }
   
   -(void)viewDidLoad{
       if (![self.rootViewController.view viewWithTag:BackButtonTag]) {
           [self.rootViewController.view addSubview:self.backButton];
           [self.rootViewController.view bringSubviewToFront:self.backButton];
       }
   }
   
   - (void)actionBack{
       backToNative();
   }
   
   - (UIButton *)backButton{
       if (!_backButton) {
           _backButton = [UIButton buttonWithType:UIButtonTypeCustom];
           _backButton.frame = CGRectMake(10, 10, 60, 44);
           _backButton.backgroundColor = [UIColor clearColor];
           [_backButton setTitle:@"退出" forState:UIControlStateNormal];
           [_backButton setTitleColor:[UIColor lightGrayColor] forState:UIControlStateNormal];
           [_backButton addTarget:self action:@selector(actionBack) forControlEvents:UIControlEventTouchUpInside];
           _backButton.tag = BackButtonTag;
       }
       return _backButton;
   }
   
   - (void)dealloc{
       [[NSNotificationCenter defaultCenter] removeObserver:self];
   }
   
   @end
   

6. 修改AppDelegate,将AppDelegate.m修改为AppDelegate.mm，并创建新的Unity3d入口。

   //AppDelegate.h
   #import <UIKit/UIKit.h>
   @class UnityAppController;
   @interface AppDelegate : UIResponder <UIApplicationDelegate>
   @property (strong, nonatomic) UIWindow *window;
   @property (strong, nonatomic) UIWindow *unityWindow;
   @property (strong, nonatomic) UnityAppController *unityController;
   -(void)showUnityWindow;
   -(void)hideUnityWindow;
   @end
   
   //AppDelegate.mm
   #import "AppDelegate.h"
   #import <IQKeyboardManager.h>
   #import "MyARAppController.h"
   
   @interface AppDelegate ()
   @property (nonatomic,strong) UINavigationController *navVC;
   @end
   
   @implementation AppDelegate
   
   -(UIWindow *)unityWindow{
       return UnityGetMainWindow();
   }
   
   -(void)showUnityWindow{
       self.unityWindow.hidden = NO;
       UnitySendMessage("CameraDevice", "StartCapture", "");
   }
   
   -(void)hideUnityWindow{
       self.unityWindow.hidden = YES;
       UnitySendMessage("CameraDevice", "StopCapture", "");
   }
   
   - (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
       self.window = [[UIWindow alloc]initWithFrame:[UIScreen mainScreen].bounds];
       self.window.backgroundColor = [UIColor whiteColor];
       UIStoryboard *sb = [UIStoryboard storyboardWithName:@"Main" bundle:nil];
       self.navVC = [sb instantiateInitialViewController];
       self.window.rootViewController = self.navVC;
       [self.window makeKeyAndVisible];
       
       self.unityController = [[MyARAppController alloc]init];
       [self.unityController application:application didFinishLaunchingWithOptions:launchOptions];
       [self hideUnityWindow];
     
       return YES;
   }
   
   - (void)applicationWillResignActive:(UIApplication *)application {
       [self.unityController applicationWillResignActive:application];
   }
   - (void)applicationDidEnterBackground:(UIApplication *)application {
       [self.unityController applicationDidEnterBackground:application];
   }
   - (void)applicationWillEnterForeground:(UIApplication *)application {
       [self.unityController applicationWillEnterForeground:application];
   }
   - (void)applicationDidBecomeActive:(UIApplication *)application {
       [self.unityController applicationDidBecomeActive:application];
   }
   - (void)applicationWillTerminate:(UIApplication *)application {
       [self.unityController applicationWillTerminate:application];
   }
   
   @end
   

7. 设置入口，此处以ViewController作为入口控制器。

   #import "ViewController.h"
   #import "AppDelegate.h"
   @implementation ViewController
   - (void)viewDidLoad {
       [super viewDidLoad];
       UIButton * enterBtn = [UIButton buttonWithType:UIButtonTypeSystem];
       enterBtn.frame = CGRectMake(0, 0, 100, 100);
       enterBtn.center = self.view.center;
       [enterBtn setTitle:@"进入" forState:UIControlStateNormal];
       [enterBtn addTarget:self action:@selector(didClickEnter:) forControlEvents:UIControlEventTouchUpInside];
       [self.view addSubview:enterBtn];
   }
   
   -(void)didClickEnter:(UIButton*)btn{
        //唤起unity界面
       AppDelegate * delegate = [UIApplication sharedApplication].delegate;
       [delegate showUnityWindow];
   }
   @end
   

躺过的坑

1. 编译成功后，APP启动时crash：il2cpp::vm::MetadataCache::Initialize{}

解决办法是在 Other C Flags选项中添加 -DRUNTIME_IL2CPP=1 参数。