Project Tango应该说是Google一试水AR的设备,其中Project Tango主要二个功能,一个是获取深度信息,如MS的Kinect,有相当多的设备都有这个功能,二是第一人称相对定位,这个就没那么常见了,如果对这个设备有更深的兴趣,可以看知乎上的这二个链接。
Google Project Tango获取深度信息的原理是什么?
Project tango是如何仅凭自身摄像头实现位置追踪的?
在这就不仔细来说这个东东了,上面二个链接比我自己再来说篇好多了,Project Tango本身有Unity3D的包(googlesamples/tango-examples-unity)如果在Unity3D下开发,相应的东东都已经提供,还有一些实例,能够很容易就开发基于Project Tango的功能出来。
UE4下就比较麻烦了,google没有针对UE4做相应的包,不过,google提供针对安卓开发的项目,一种是Android Studio项目,一个是供JNI调用的C语言项目。
googlesamples/tango-examples-java
googlesamples/tango-examples-c
UE4针对移动平台感觉还是不那么友好,如Unity调用Android项目,大家顺便一搜,都能搞定,而在UE4下引用安卓项目,如下是一个添加针对Android支持Google Play功能的committed。
UE4 Google Play support on Android
可以看到,有些复杂,特别针对我这种UE4与Android都不熟的人,只有想别办法,首先我的需求并不复杂,只是在一个模型与现实重叠的空间利用Project Tango的Motion tracking功能行走,旋转等,简单来说,我现在的办公室环境,利用3D建模做一个和办公室一样的模型,长宽都要对上,这样利用Project Tango 的Tracking,我能只看屏幕也知道我在办公室的那个位置,前面是否有障碍物,就如HTV vive的那二个像个小音箱的东东来检测可活动区域一样。
UE4本身的脚本就是C++语言,自然我就想到利用上面的tango c来做开发,如下主要记录本文实践这种方法遇到的一些问题。
首先安装UE4的安卓开发相关所有软件,UE4已经帮你差不多都搞好。安装安卓软件开发工具包(SDK) ,然后对照这个链接下的UE4安卓快速入门自己测试,一个简单的UE4 安卓程序发出来就没问题了。
tango-examples-c里很简单,一个so文件,相当于win平台中的动态链接库文件,二是一个头文件tango_client_api.h.现在就很简单了,相当于平常我们写C++程序一样,引入动态链接库,然后添加头文件就可,但是UE4中,编译都是靠对应目录下的cs文件编译,我们需要让UE4的规则来引入库与头文件。
按照UE4大家默认的一些目录位置与命名,先把相应头文件与库放入一个ThirdParth文件夹,然后放入UE4工程文件件,与Source,Binaries等目录平行,如下:
然后打开工程名.Build.cs文件,告诉编译器我们需要引入的库与文件。
public class Office_05 : ModuleRules { public Office_05(TargetInfo Target) { PublicDependencyModuleNames.AddRange(new string[] { "Core", "CoreUObject", "Engine", "InputCore", "Launch", "UMG" }); //PrivateDependencyModuleNames.AddRange(new string[] { "" }); //PublicIncludePaths.Add("Runtime/Launch/Public"); //PrivateIncludePaths.Add("Runtime/Launch/Private/Android"); if (Target.Platform == UnrealTargetPlatform.Android) { PublicIncludePaths.AddRange(new string[] { "Core" }); PublicIncludePaths.Add("C:/NVPACK/android-ndk-r10e/platforms/android-19/arch-arm/usr/include"); LoadBobsMagic(Target); } } private string ModulePath { get { return Path.GetDirectoryName(RulesCompiler.GetModuleFilename(this.GetType().Name)); } } private string ThirdPartyPath { get { return Path.GetFullPath(Path.Combine(ModulePath, "../../ThirdParty/")); } } public bool LoadBobsMagic(TargetInfo Target) { bool isLibrarySupported = false; if (Target.Platform == UnrealTargetPlatform.Android) { isLibrarySupported = true; string LibrariesPath = Path.Combine(ThirdPartyPath, "tango_client_api", "lib"); PublicAdditionalLibraries.Add(Path.Combine(LibrariesPath, "libtango_client_api.so")); } if (isLibrarySupported) { // Include path PublicIncludePaths.Add(Path.Combine(ThirdPartyPath, "tango_client_api", "include")); } //Definitions.Add(string.Format("WITH_LIBZPLAY_BINDING={0}", isLibrarySupported ? 1 : 0)); return isLibrarySupported; } }
UE4 引入库
PublicDependencyModuleNames我们新添加Launch与UMG,因为我们需要引用这二个库,不然后面引用#include "Android/AndroidJNI.h"里的功能会告诉你没有实现,还有一点特别注意,安卓的功能一定要包含预处理定义PLATFORM_ANDROID当中,当初特别二的以为编译选项选择Android后,就可以直接写NDK代码了,当然现在的编译是由UE4来控制的,所以不用看VS中的错误列表,只需要看VS中的输出,如果提示生成成功,没有error,就可以在设备上发布了。
然后我们包装一下tango_client_api.h里的功能,演示如何在安卓环境下调用JNIEnv,当前active等。
#pragma once #include "Components/TextRenderComponent.h" #include "Office_05.h" #include "MyCharacter.h" #include "TangoApp.h" #include "Engine/TextRenderActor.h" #include "Components/TextRenderComponent.h" #if PLATFORM_ANDROID #include "tango_client_api.h" #include "Android/AndroidApplication.h" #include "Android/AndroidJava.h" #include "Android/AndroidJNI.h" #endif /** * */ class OFFICE_05_API TangoApp { private: static class UTextRenderComponent* textRender; static FVector translation; static FQuat quat; public: TangoApp(); ~TangoApp(); static FVector& GetTranslation() { return translation; } static FQuat& GetQuat() { return quat; } static void SetTextRender(class UTextRenderComponent* tRender) { textRender = tRender; appendText(textRender, TEXT("VV")); } static void appendText(UTextRenderComponent* textCompent, const FString& value, bool overrid = false) { if (textCompent == nullptr) return; if (!overrid) { FText text = textCompent->Text; FString newText = text.BuildSourceString(); newText.Append(" "); newText.Append(value); textCompent->SetText(FText::FromString(newText)); } else { textCompent->SetText(FText::FromString(value)); } } #if PLATFORM_ANDROID static void InitTango() { JNIEnv* Env = FAndroidApplication::GetJavaEnv(); jint VersionJint = Env->GetVersion(); int8 Version = (int8)VersionJint; TangoApp::appendText(textRender, FString::FromInt(Version)); jobject currentActive = FAndroidApplication::GetGameActivityThis(); TangoErrorType type = TangoService_initialize(Env, currentActive); TangoApp::appendText(textRender, FString::FromInt((int)type)); //type = TangoService_setBinder(Env, currentActive); TangoApp::appendText(textRender, TEXT("A")); TangoApp::appendText(textRender, FString::FromInt((int)type)); auto tangoConfig = TangoService_getConfig(TANGO_CONFIG_DEFAULT); type = TangoConfig_setBool(tangoConfig, "config_enable_motion_tracking", true); TangoApp::appendText(textRender, FString::FromInt((int)type)); if (type == TANGO_SUCCESS) { TangoApp::appendText(textRender, TEXT("B")); } type = TangoConfig_setBool(tangoConfig, "config_enable_auto_recovery", true); TangoApp::appendText(textRender, FString::FromInt((int)type)); if (type == TANGO_SUCCESS) { TangoApp::appendText(textRender, TEXT("C")); } type = TangoConfig_setBool(tangoConfig, "config_enable_learning_mode", true); TangoApp::appendText(textRender, FString::FromInt((int)type)); if (type == TANGO_SUCCESS) { TangoApp::appendText(textRender, TEXT("D")); } //TangoApp::Launch(); //TangoApp::appendText(text->GetTextRender(), TangoApplication::getPackageName()); //uuid得不到,相应权限申请不成功,请看TangoApplication::Launch char* uuidList = NULL; type = TangoService_getAreaDescriptionUUIDList(&uuidList); TangoApp::appendText(textRender, FString::FromInt((int)type)); if (type == TANGO_SUCCESS) { int lenght = 0; for (int i = 0; i < 1000; i++) { if (uuidList[i] != 0) ++lenght; else { break; } } FString suuidList(uuidList); TangoApp::appendText(textRender, FString::FromInt(lenght)); } TangoCoordinateFramePair pair; pair.base = TANGO_COORDINATE_FRAME_START_OF_SERVICE; pair.target = TANGO_COORDINATE_FRAME_DEVICE; //用来验证相应数据 //TangoPoseData* poseData = new TangoPoseData(); //pair.base = TANGO_COORDINATE_FRAME_IMU; //pair.target = TANGO_COORDINATE_FRAME_CAMERA_COLOR; //TangoService_getPoseAtTime(0, pair, poseData); //type = TangoService_connectOnTangoEvent(&TangoApp::onTangoConnectEvent); //TangoApp::appendText(textRender), TEXT("E")); //TangoApp::appendText(textRender, FString::FromInt((int)type)); type = TangoService_connectOnPoseAvailable(1, &pair, &TangoApp::TangoService_onPoseAvailable); TangoApp::appendText(textRender, TEXT("F")); TangoApp::appendText(textRender, FString::FromInt((int)type)); //FAppEventManager::GetInstance()->PauseRendering(); type = TangoService_connect(nullptr, tangoConfig); TangoApp::appendText(textRender, FString::FromInt((int)type)); //FAppEventManager::GetInstance()->ResumeRendering(); } static FString getPackageName() { if (JNIEnv* Env = FAndroidApplication::GetJavaEnv(true)) { auto getPackageMethod = FJavaWrapper::FindMethod(Env, FJavaWrapper::GameActivityClassID, "getPackageName", "()Ljava/lang/String;", false); jstring jsString = (jstring)FJavaWrapper::CallObjectMethod(Env, FJavaWrapper::GameActivityThis, getPackageMethod); check(jsString); const char * nativeName = Env->GetStringUTFChars(jsString, 0); FString ResultName = FString(nativeName); Env->ReleaseStringUTFChars(jsString, nativeName); Env->DeleteLocalRef(jsString); return ResultName; } return FString(); } static void Launch() { if (JNIEnv* Env = FAndroidApplication::GetJavaEnv(true)) { //申请ADF权限 auto intentClass = Env->FindClass("android/content/Intent"); auto Constructor = Env->GetMethodID(intentClass, "<init>", "()V"); auto intentObject = Env->NewObject(intentClass, Constructor); auto intentMethod = FJavaWrapper::FindMethod(Env, intentClass, "setClassName", "(Ljava/lang/String;Ljava/lang/String;)V", false); //auto putExtraMethod = FJavaWrapper::FindMethod(Env, intentClass, "putExtra", "(Ljava/lang/String;Ljava/lang/String;)V", false); /* FJavaWrapper::CallVoidMethod(Env, intentObject, intentMethod, "com.projecttango.tango", "com.google.atap.tango.RequestPermissionActivity"); FJavaWrapper::CallVoidMethod(Env, intentObject, putExtraMethod, "PERMISSIONTYPE", "ADF_LOAD_SAVE_PERMISSION"); auto startAMehtod = FJavaWrapper::FindMethod(Env, FJavaWrapper::GameActivityClassID, "startActivity", "(android/content/Intent;)V", false); */ //FJavaWrapper::CallVoidMethod(Env, currentActive, startAMehtod, intentObject); //check(object); //auto intentObject = Env->NewGlobalRef(object); Env->DeleteLocalRef(intentObject); } //auto intentMethod = FJavaWrapper::FindMethod(Env, intentClass, "setClassName", "(Ljava/lang/String;Ljava/lang/String;)V", false); //auto putExtraMethod = FJavaWrapper::FindMethod(Env, intentClass, "putExtra", "(Ljava/lang/String;Ljava/lang/String;)V", false); /* FJavaWrapper::CallVoidMethod(Env, intentObject, intentMethod, "com.projecttango.tango", "com.google.atap.tango.RequestPermissionActivity"); FJavaWrapper::CallVoidMethod(Env, intentObject, putExtraMethod, "PERMISSIONTYPE", "ADF_LOAD_SAVE_PERMISSION"); auto startAMehtod = FJavaWrapper::FindMethod(Env, FJavaWrapper::GameActivityClassID, "startActivity", "(android/content/Intent;)V", false); */ //FJavaWrapper::CallVoidMethod(Env, currentActive, startAMehtod, intentObject); //FJavaClassObject intentObject(FName("android/content/Intent"), "()V"); //auto intentMethod = intentObject.GetClassMethod("setClassName", "(Ljava/lang/String;Ljava/lang/String;)V"); //auto putExtraMethod = intentObject.GetClassMethod("putExtra", "(Ljava/lang/String;Ljava/lang/String;)V"); //intentObject.CallMethod(intentMethod, "com.projecttango.tango", "com.google.atap.tango.RequestPermissionActivity"); //intentObject.CallMethod(intentMethod, "PERMISSIONTYPE", "ADF_LOAD_SAVE_PERMISSION"); //auto startAMehtod = FJavaWrapper::FindMethod(Env, FJavaWrapper::GameActivityClassID, "startActivity", "(android/content/Intent;)V", false); //FJavaWrapper::CallVoidMethod(Env, currentActive, startAMehtod, intentObject.GetJObject()); //auto tangoClass = Env->GetObjectClass(currentActive); //auto tangoMethod = FJavaWrapper::FindMethod(FAndroidApplication::GetJavaEnv(true), FJavaWrapper::GameActivityClassID, "launchIntent", "(Ljava/lang/String;Ljava/lang/String;[Ljava/lang/String;I)V", false); //auto tangoMethod = FJavaWrapper::FindMethod(Env, tangoClass, "launchIntent", "(Ljava/lang/String;Ljava/lang/String;[Ljava/lang/String;I)V", false); //if (tangoMethod != nullptr) //{ // TangoApplication::appendText(text->GetTextRender(), TEXT("C")); // //使用方法请看AndroidJNI.cpp ->AndroidThunkCpp_Iap_QueryInAppPurchases // jobjectArray tArgs = (jobjectArray)Env->NewObjectArray(1, FJavaWrapper::JavaStringClass, NULL); // jstring StringValue = Env->NewStringUTF(TCHAR_TO_UTF8("PERMISSIONTYPE:ADF_LOAD_SAVE_PERMISSION")); // Env->SetObjectArrayElement(tArgs, 0, StringValue); // Env->DeleteLocalRef(StringValue); // FJavaWrapper::CallVoidMethod(Env, currentActive, tangoMethod, "com.projecttango.tango", // "com.google.atap.tango.RequestPermissionActivity", tArgs, 43); //} } static void onTangoConnectEvent(void* context, const TangoEvent* event) { appendText(textRender, TEXT("Connect"), true); appendText(textRender, FString::SanitizeFloat(event->timestamp)); } //Unity x左右,y上下,z前后 左手 //https://developers.google.com/project-tango/overview/coordinate-systems#project_tango_coordinate_frames //Tango START_OF_SERVICE x左右,y前后,z上下 右手 //Tango Device_Frame x左右,y上下,z前后 右手 //UE4 x前后,y左右,z上下 左手 static void TangoService_onPoseAvailable(void* context, const TangoPoseData* pose) { if (pose->status_code == TANGO_POSE_VALID && pose->frame.base == TANGO_COORDINATE_FRAME_START_OF_SERVICE && pose->frame.target == TANGO_COORDINATE_FRAME_DEVICE ) { translation[0] = pose->translation[0] * 100; translation[1] = pose->translation[1] * 100; translation[2] = pose->translation[2] * 100; quat.X = pose->orientation[0]; quat.Y = pose->orientation[1]; quat.Z = pose->orientation[2]; quat.W = pose->orientation[3]; } else { } } #endif }; "C++文件" #include "Office_05.h" #include "TangoApp.h" class UTextRenderComponent* TangoApp::textRender = nullptr; FVector TangoApp::translation = FVector::ZeroVector; FQuat TangoApp::quat = FQuat::Identity; TangoApp::TangoApp() { } TangoApp::~TangoApp() { }
TangoApp
在这里有个失败的尝试,我想通过NDK来申请ADF(区域文件相关权限),见上面的Launch方法,总是在调用CallVoidMethod时失败,而上面的getPackageName又没有问题,想不出来是啥问题。
通过工具Android Device Monitor,一般来说如果按照UE4的安卓工具包的流程来安装,这个工具在目录C:\NVPACK\android-sdk-windows\tools\monitor.bat下,打开Android Device Monitor,一般来说,我们新建一个Filters,如下图设置。
如上图设置后,我们得到错误信息是FindMethod得到的方法为空,到这一步后,相关参数应该没有问题,可能是还要引入新的库,总之,在这我们得不到区域文件,那么我们不能通过区域文件来定义,只能通过设备开始位置来定位了,这样我们需要在特定的位置,特定的方向打开这个程序才能正确tracking现实与模型,这样限制太大,所以我们需要提供一UI可以自己修改位置与方向,这样,在开始时,我们先调到我们本身的位置与方向与项目的位置与方向重合。还好,这个东东并不需要我们多花费时间,UE4里本身的功能与内容包里,就有一个C++功能First Person,我们添加到项目中,这个在安卓下就提供二个圈给我们,一个圈调整水平位置,一个调整视角方向,刚好满足我们的需求,现在我们结合First Person与Tango,让Tango本身的路径追踪来替代First Person里的行走,如下是主要的修改位置。
void AFP_FirstPersonCharacter::BeginPlay() { Super::BeginPlay(); text = FindActor<ATextRenderActor>(TEXT("TextRenderActor2")); text1 = FindActor<ATextRenderActor>(TEXT("TextRenderActor3")); TangoApp::SetTextRender(text->GetTextRender()); #if PLATFORM_ANDROID TangoApp::InitTango(); //TangoApp::Launch(); #endif TangoApp::appendText(text->GetTextRender(), TEXT("T"), true); TangoApp::appendText(text1->GetTextRender(), TEXT("R"), true); } void AFP_FirstPersonCharacter::Tick(float DeltaTime) { Super::Tick(DeltaTime); #if PLATFORM_ANDROID //Tango Device_Frame/OpenGL x左右,y上下,z前后 右手 //UE4 x前后,y左右,z上下 左手 //Tango START_OF_SERVICE x左右,y前后,z上下 右手 //Unity x左右,y上下,z前后 左手 ////Device_Frame (Unreal camera to Drive) //FMatrix ucTd(-FVector::UpVector, FVector::ForwardVector, FVector::RightVector, FVector::ZeroVector); ////(Drive to START_SERVICE) //FTransform dTss(TangoApp::GetQuat(), TangoApp::GetTranslation(), FVector(1, 1, 1)); ////X,Y互换 (START_SERVICE to Unreal world) //FMatrix ssTuw(FVector::RightVector, -FVector::ForwardVector, FVector::UpVector, FVector::ZeroVector); ////ucTd * dTss * ssTuw //FTransform dTuw = FTransform(ucTd) * dTss * FTransform(ssTuw); //SetActorRelativeLocation(dTuw.GetLocation()); //auto rotator = dTuw.Rotator();// (dTuw.GetRotation() * FQuat::FQuat(FVector::ForwardVector, -PI / 2.0f)).Rotator(); //dTuw.Rotator();// auto ToConvert = TangoApp::GetQuat(); auto translation = TangoApp::GetTranslation(); FQuat TangoToUnrealQuat(ToConvert.Z, -ToConvert.X, -ToConvert.Y, ToConvert.W); //0.7071(rad/2) angle = 90 axis = (0,1,0) FQuat ConvertedQuat = (FQuat(0.0, 0.7071, 0.0, 0.7071) * TangoToUnrealQuat); if (WeaponRange < 0 || WeaponRange >100) { WeaponRange = 0; } FVector ConvertedFVector = 1 * cRotaror.RotateVector(FVector(translation[1], translation[0], translation[2] + WeaponRange)) + cPostion; SetActorRelativeLocation(ConvertedFVector); FRotator rotator = ConvertedQuat.Rotator() + cRotaror; if (Controller != nullptr) { Controller->SetControlRotation(rotator); } //if (GEngine) //{ // auto quat = ConvertedQuat; //dTuw.GetRotation();// // GEngine->AddOnScreenDebugMessage(0, 30.f, FColor::Red, "X:" + FString::SanitizeFloat(quat.X) // + " Y:" + FString::SanitizeFloat(quat.Y) // + " Z:" + FString::SanitizeFloat(quat.Z)); //} #endif if (GEngine) { GEngine->AddOnScreenDebugMessage(0, 30.f, FColor::Red, "H:" + FString::SanitizeFloat(WeaponRange)); } } void AFP_FirstPersonCharacter::MoveForward(float Value) { if (Value != 0.0f) { // Add movement in that direction AddMovementInput(GetActorForwardVector(), Value); cPostion += GetActorForwardVector()*Value; } } void AFP_FirstPersonCharacter::MoveRight(float Value) { if (Value != 0.0f) { // Add movement in that direction AddMovementInput(GetActorRightVector(), Value); cPostion += GetActorRightVector()*Value; } } void AFP_FirstPersonCharacter::TurnAtRate(float Rate) { // Calculate delta for this frame from the rate information AddControllerYawInput(Rate * BaseTurnRate * GetWorld()->GetDeltaSeconds()); cRotaror.Yaw += Rate * BaseTurnRate * GetWorld()->GetDeltaSeconds(); } void AFP_FirstPersonCharacter::LookUpAtRate(float Rate) { // Calculate delta for this frame from the rate information AddControllerPitchInput(Rate * BaseLookUpRate * GetWorld()->GetDeltaSeconds()); cRotaror.Pitch += Rate * BaseLookUpRate * GetWorld()->GetDeltaSeconds(); }
Tango Tracking
Tango里需要注意,每个摄像机,还有设备本身都采用不同的坐标系,如下图。
想看更完全的介绍,请看 coordinate-systems 这个链接,如果不能打开,提示二个字,红杏。
嗯,在这差不多了,一个简单利用Tango tracking,漫游办公室的小程序就有了,是不是有点AR的感觉。Tango这部分就差不多完了,但是有个小问题,UI能调整水平方向,高度不能调整,我们增加一个调整高度的UI,顺便演练下蓝图调用C++的API的方法。
首先我们创建一个基于GameMode的我们自己的MyGameMode.
然后和上面一样,创建一个基于HUD的自己的MyHUD,在MyGameMode中的HUD选择MyHUD,在蓝图中,我们选择添加用户控件里的用户蓝图,名字设为MyGUI.
在MyHUD中,添加MyGUI到视图中,相应蓝图设置如下。
在MyGUI中添加一个Slider,其中OnValueChanged中设置如下:
其中FP_FirstPersonCharacter添加如下方法。
UFUNCTION(BlueprintCallable, Category = "Game") void SetHeight(float height);
SetHeight
特性声明BlueprintCallable,其中Category是在蓝图中添加方法的分组名。
差不多完了,最后想起一个问题,在从Unity 到 UE4 的快速上手与迁移 里的一个API,FindObject<T>,使用不成功,在AActor里使用反正得不到结果,同样的参数,传入如下函数就可以。
template< class T > T* FindActor(FString name) { for (TActorIterator<T> It(GetWorld()); It; ++It) { T* actor = *It; if (It->GetName() == name) { return actor; } } return nullptr; }
FindActor
有知道的同学可以说下。