虚幻C++基础 day3

常见的游戏机制

Actor机关门

• 创建一个Actor类，添加两个静态网格与一个触发器

  • UBoxComponent
  • UStaticMeshComponent

• 头文件：

  • #include “Components/BoxComponent.h”
  • #include “Components/StaticMeshComponent.h”

TriggerDoor.h

// Fill out your copyright notice in the Description page of Project Settings.#pragma once#include "CoreMinimal.h"
#include "GameFramework/Actor.h"
#include "TriggerDoor.generated.h"UCLASS()
class UEGAME_API ATriggerDoor : public AActor
{GENERATED_BODY()public:	// Sets default values for this actor's propertiesATriggerDoor();UPROPERTY(VisibleAnywhere, BlueprintReadWrite)class UBoxComponent* TriggerBox;UPROPERTY(VisibleAnywhere, BlueprintReadWrite)class UStaticMeshComponent* TriggerMesh;UPROPERTY(VisibleAnywhere, BlueprintReadWrite)UStaticMeshComponent* DoorMesh;protected:// Called when the game starts or when spawnedvirtual void BeginPlay() override;public:	// Called every framevirtual void Tick(float DeltaTime) override;};

TriggerDoor.cpp

// Fill out your copyright notice in the Description page of Project Settings.#include "TriggerDoor.h"
#include "Components/BoxComponent.h"
#include "Components/StaticMeshComponent.h"
// Sets default values
ATriggerDoor::ATriggerDoor()
{// Set this actor to call Tick() every frame.  You can turn this off to improve performance if you don't need it.PrimaryActorTick.bCanEverTick = true;TriggerBox = CreateDefaultSubobject<UBoxComponent>(TEXT("TriggerBox"));RootComponent = TriggerBox;TriggerMesh = CreateDefaultSubobject<UStaticMeshComponent>(TEXT("TriggerMesh"));TriggerMesh->SetupAttachment(GetRootComponent());DoorMesh = CreateDefaultSubobject<UStaticMeshComponent>(TEXT("DoorMesh"));DoorMesh->SetupAttachment(GetRootComponent());}// Called when the game starts or when spawned
void ATriggerDoor::BeginPlay()
{Super::BeginPlay();}// Called every frame
void ATriggerDoor::Tick(float DeltaTime)
{Super::Tick(DeltaTime);}

设置材质上去

• 直接采用场景里面的材质附着上去即可
  

编写位置更新函数

• 修好好位置后点击这个就可以实例同步到蓝图中
  
  

蓝图中的时间轴函数(Timeline)与UE多播委托机制

多播委托

• 触发器中提供了两个与一个绑定宏用来判断组件是否被重叠，这两个函数是要参与UE反射系统的，我们需要使用UFUNCTION进行标明，UFUNCTION里面可以什么参数不要，我们称这个操作为多播委托
  • OnComponentBeginOverlap：事件，当某些内容开始与此组件重叠时调用，例如玩家进入触发器。
  • OnComponentEndOverlap：事件，当组件停止重叠时调用
• AddDynamic宏：这个宏需要传入一个绑定函数，绑定函数参数格式如下UE源码,因为UE是把参数与参数类型都当做参数了，所以我们需要把逗号删除，一般是从开头数字乘2，从参数最后面开始选择，例如：SixParams(...)，也就是6*2=12个参数，从函数尾部开始复制12个参数，注意UE4.23之后的版本可能参数不一样

/*** Delegate for notification of blocking collision against a specific component.  * NormalImpulse will be filled in for physics-simulating bodies, but will be zero for swept-component blocking collisions. */
DECLARE_DYNAMIC_MULTICAST_DELEGATE_FiveParams( FComponentHitSignature, UPrimitiveComponent*, HitComponent, AActor*, OtherActor, UPrimitiveComponent*, OtherComp, FVector, NormalImpulse, const FHitResult&, Hit );
/** Delegate for notification of start of overlap with a specific component */
DECLARE_DYNAMIC_MULTICAST_DELEGATE_SixParams( FComponentBeginOverlapSignature, UPrimitiveComponent*, OverlappedComponent, AActor*, OtherActor, UPrimitiveComponent*, OtherComp, int32, OtherBodyIndex, bool, bFromSweep, const FHitResult &, SweepResult);
/** Delegate for notification of end of overlap with a specific component */
DECLARE_DYNAMIC_MULTICAST_DELEGATE_FourParams( FComponentEndOverlapSignature, UPrimitiveComponent*, OverlappedComponent, AActor*, OtherActor, UPrimitiveComponent*, OtherComp, int32, OtherBodyIndex);
/** Delegate for notification when a wake event is fired by physics*/
DECLARE_DYNAMIC_MULTICAST_DELEGATE_TwoParams(FComponentWakeSignature, UPrimitiveComponent*, WakingComponent, FName, BoneName);
/** Delegate for notification when a sleep event is fired by physics*/
DECLARE_DYNAMIC_MULTICAST_DELEGATE_TwoParams(FComponentSleepSignature, UPrimitiveComponent*, SleepingComponent, FName, BoneName);
/** Delegate for notification when collision settings change. */
DECLARE_DYNAMIC_MULTICAST_DELEGATE_OneParam(FComponentCollisionSettingsChangedSignature, UPrimitiveComponent*, ChangedComponent);DECLARE_DYNAMIC_MULTICAST_DELEGATE_OneParam( FComponentBeginCursorOverSignature, UPrimitiveComponent*, TouchedComponent );
DECLARE_DYNAMIC_MULTICAST_DELEGATE_OneParam( FComponentEndCursorOverSignature, UPrimitiveComponent*, TouchedComponent );
DECLARE_DYNAMIC_MULTICAST_DELEGATE_TwoParams( FComponentOnClickedSignature, UPrimitiveComponent*, TouchedComponent , FKey, ButtonPressed);
DECLARE_DYNAMIC_MULTICAST_DELEGATE_TwoParams( FComponentOnReleasedSignature, UPrimitiveComponent*, TouchedComponent, FKey, ButtonReleased);
DECLARE_DYNAMIC_MULTICAST_DELEGATE_TwoParams( FComponentOnInputTouchBeginSignature, ETouchIndex::Type, FingerIndex, UPrimitiveComponent*, TouchedComponent );
DECLARE_DYNAMIC_MULTICAST_DELEGATE_TwoParams( FComponentOnInputTouchEndSignature, ETouchIndex::Type, FingerIndex, UPrimitiveComponent*, TouchedComponent );
DECLARE_DYNAMIC_MULTICAST_DELEGATE_TwoParams( FComponentBeginTouchOverSignature, ETouchIndex::Type, FingerIndex, UPrimitiveComponent*, TouchedComponent );
DECLARE_DYNAMIC_MULTICAST_DELEGATE_TwoParams( FComponentEndTouchOverSignature, ETouchIndex::Type, FingerIndex, UPrimitiveComponent*, TouchedComponent );

• 声明两个绑定函数

public:	// Called every framevirtual void Tick(float DeltaTime) override;//自定义AddDynamic绑定的触发器函数UFUNCTION()void OnOverlapBegin(UPrimitiveComponent* OverlappedComponent, AActor* OtherActor, UPrimitiveComponent* OtherComp, int32 OtherBodyIndex, bool bFromSweep, const FHitResult& SweepResult);UFUNCTION()void OnOverlapEnd(UPrimitiveComponent* OverlappedComponent, AActor* OtherActor, UPrimitiveComponent* OtherComp, int32 OtherBodyIndex);
};

• 将多播委托进行绑定

// Called when the game starts or when spawned
void ATriggerDoor::BeginPlay()
{Super::BeginPlay();//绑定事件TriggerBox->OnComponentBeginOverlap.AddDynamic(this, &ATriggerDoor::OnOverlapBegin);TriggerBox->OnComponentEndOverlap.AddDynamic(this, &ATriggerDoor::OnOverlapEnd);
}// Called every frame
void ATriggerDoor::Tick(float DeltaTime)
{Super::Tick(DeltaTime);}void ATriggerDoor::OnOverlapBegin(UPrimitiveComponent* OverlappedComponent, AActor* OtherActor, UPrimitiveComponent* OtherComp, int32 OtherBodyIndex, bool bFromSweep, const FHitResult& SweepResult)
{
}void ATriggerDoor::OnOverlapEnd(UPrimitiveComponent* OverlappedComponent, AActor* OtherActor, UPrimitiveComponent* OtherComp, int32 OtherBodyIndex)
{
}

指定触发器只响应Pawn

	//设置TriggerBox碰撞的硬编码TriggerBox->SetCollisionEnabled(ECollisionEnabled::QueryOnly);//设置碰撞类型TriggerBox->SetCollisionObjectType(ECollisionChannel::ECC_WorldStatic);//设置对象移动时其应视为某种物体TriggerBox->SetCollisionResponseToAllChannels(ECollisionResponse::ECR_Ignore);//设置所有的碰撞响应为忽略TriggerBox->SetCollisionResponseToChannel(ECollisionChannel::ECC_Pawn, ECollisionResponse::ECR_Overlap);//设置Pawn碰撞响应为重叠

TriggerDoor.h

// Fill out your copyright notice in the Description page of Project Settings.#pragma once#include "CoreMinimal.h"
#include "GameFramework/Actor.h"
#include "TriggerDoor.generated.h"UCLASS()
class UEGAME_API ATriggerDoor : public AActor
{GENERATED_BODY()public:	// Sets default values for this actor's propertiesATriggerDoor();UPROPERTY(VisibleAnywhere, BlueprintReadWrite)class UBoxComponent* TriggerBox;UPROPERTY(VisibleAnywhere, BlueprintReadWrite)class UStaticMeshComponent* TriggerMesh;UPROPERTY(VisibleAnywhere, BlueprintReadWrite)UStaticMeshComponent* DoorMesh;protected:// Called when the game starts or when spawnedvirtual void BeginPlay() override;public:	// Called every framevirtual void Tick(float DeltaTime) override;//自定义AddDynamic绑定的触发器函数UFUNCTION()void OnOverlapBegin(UPrimitiveComponent* OverlappedComponent, AActor* OtherActor, UPrimitiveComponent* OtherComp, int32 OtherBodyIndex, bool bFromSweep, const FHitResult& SweepResult);UFUNCTION()void OnOverlapEnd(UPrimitiveComponent* OverlappedComponent, AActor* OtherActor, UPrimitiveComponent* OtherComp, int32 OtherBodyIndex);
};

TriggerDoor.cpp

// Fill out your copyright notice in the Description page of Project Settings.#include "TriggerDoor.h"
#include "Components/BoxComponent.h"
#include "Components/StaticMeshComponent.h"
#include "Characters/Player/MainPlayer.h"
// Sets default values
ATriggerDoor::ATriggerDoor()
{// Set this actor to call Tick() every frame.  You can turn this off to improve performance if you don't need it.PrimaryActorTick.bCanEverTick = true;TriggerBox = CreateDefaultSubobject<UBoxComponent>(TEXT("TriggerBox"));RootComponent = TriggerBox;TriggerBox->SetBoxExtent(FVector(60.f, 60.f, 30.f));//设置TriggerBox碰撞的硬编码TriggerBox->SetCollisionEnabled(ECollisionEnabled::QueryOnly);//设置碰撞类型TriggerBox->SetCollisionObjectType(ECollisionChannel::ECC_WorldStatic);//设置对象移动时其应视为某种物体TriggerBox->SetCollisionResponseToAllChannels(ECollisionResponse::ECR_Ignore);//设置所有的碰撞响应为忽略TriggerBox->SetCollisionResponseToChannel(ECollisionChannel::ECC_Pawn, ECollisionResponse::ECR_Overlap);//设置Pawn碰撞响应为重叠TriggerMesh = CreateDefaultSubobject<UStaticMeshComponent>(TEXT("TriggerMesh"));TriggerMesh->SetupAttachment(GetRootComponent());DoorMesh = CreateDefaultSubobject<UStaticMeshComponent>(TEXT("DoorMesh"));DoorMesh->SetupAttachment(GetRootComponent());}// Called when the game starts or when spawned
void ATriggerDoor::BeginPlay()
{Super::BeginPlay();TriggerBox->OnComponentBeginOverlap.AddDynamic(this, &ATriggerDoor::OnOverlapBegin);TriggerBox->OnComponentEndOverlap.AddDynamic(this, &ATriggerDoor::OnOverlapEnd);
}// Called every frame
void ATriggerDoor::Tick(float DeltaTime)
{Super::Tick(DeltaTime);}void ATriggerDoor::OnOverlapBegin(UPrimitiveComponent* OverlappedComponent, AActor* OtherActor, UPrimitiveComponent* OtherComp, int32 OtherBodyIndex, bool bFromSweep, const FHitResult& SweepResult)
{AMainPlayer* Player = Cast<AMainPlayer>(OtherActor);if (Player){}
}void ATriggerDoor::OnOverlapEnd(UPrimitiveComponent* OverlappedComponent, AActor* OtherActor, UPrimitiveComponent* OtherComp, int32 OtherBodyIndex)
{AMainPlayer* Player = Cast<AMainPlayer>(OtherActor);if (Player){}
}

BlueprintImplementableEvent参数的使用

• 新建几个函数用来升起降下门，关闭打开门
• BlueprintImplementableEvent：会把函数变成一个事件，把函数提升为事件后，就不能去初始化函数了，因为这个是在蓝图调用的事件
  
  

编写更新函数在蓝图中使用

• 新建两个用于更新的函数在蓝图中调用，新建两个变量用来获取当前门与触发器的offset，用于更新函数中去进行位置移动

//获取门与触发器位置
UPROPERTY(BluerprintReadWrite,Category = "Trigger Door|Trigger Properties")
FVector InitTriggerLoction;
UPROPERTY(BluerprintReadWrite,Category = "Trigger Door|Door Properties")
FVector InitDoorLocation;

UFUNCTION(BlueprintCallable,Category="Triggerable Door | Triggerable Switch")
void UpdateTriggerLocation(FVector offset);
UFUNCTION(BlueprintCallabel,Category= "Triggerable Door | Door Switch")
void UpdateDoorLocation(FVector offset);

• 在BeginPlay中初始化门和触发器的位置

// Called when the game starts or when spawned
void ATriggerDoor::BeginPlay()
{Super::BeginPlay();TriggerBox->OnComponentBeginOverlap.AddDynamic(this, &ATriggerDoor::OnOverlapBegin);TriggerBox->OnComponentEndOverlap.AddDynamic(this, &ATriggerDoor::OnOverlapEnd);//获取到门和触发器的位置InitTriggerLoction = TriggerMesh->GetComponentLocation();InitDoorLocation = DoorMesh->GetComponentLocation();
}

• 然后去更新函数中更新门与触发器的位置

void ATriggerDoor::UpdateTriggerLocation(FVector offset)
{//新位置=初始位置+移动后的位置FVector newLocation = InitTriggerLoction + offset;TriggerMesh->SetWorldLocation(newLocation);
}void ATriggerDoor::UpdateDoorLocation(FVector offset)
{//新位置=初始位置+移动后的位置FVector newLocation = InitDoorLocation + offset;DoorMesh->SetWorldLocation(newLocation);
}

• 然后去蓝图中连接更新函数
  

采用定时器关门

• 采用定时器关门的两种思路：
  • 思路一：我们可以在人物踩上触发器的时候开启定时器进行关门，当人物离开定时器的时候就关闭定时器
  • 思路二：我们可以定义一个bool变量(默认为false)进行判断定时器是否开启，当人物踩上触发器的时候就让变量为true，当人物离开触发器的时候就为false也就不执行定时器
• 定时器头文件：#include “TimerManager.h”
• FTimerHandleCloseDoorTimerHandle: 创建一个时间句柄
• SetTimer的六个重载函数

/*** Sets a timer to call the given native function at a set interval.  If a timer is already set* for this handle, it will replace the current timer.** @param InOutHandle			If the passed-in handle refers to an existing timer, it will be cleared before the new timer is added. A new handle to the new timer is returned in either case.* @param InObj					Object to call the timer function on.* @param InTimerMethod			Method to call when timer fires.* @param InRate				The amount of time between set and firing.  If <= 0.f, clears existing timers.* @param InbLoop				true to keep firing at Rate intervals, false to fire only once.* @param InFirstDelay			The time for the first iteration of a looping timer. If < 0.f inRate will be used.*/template< class UserClass >FORCEINLINE void SetTimer(FTimerHandle& InOutHandle, UserClass* InObj, typename FTimerDelegate::TUObjectMethodDelegate< UserClass >::FMethodPtr InTimerMethod, float InRate, bool InbLoop = false, float InFirstDelay = -1.f){InternalSetTimer(InOutHandle, FTimerUnifiedDelegate( FTimerDelegate::CreateUObject(InObj, InTimerMethod) ), InRate, InbLoop, InFirstDelay);}template< class UserClass >FORCEINLINE void SetTimer(FTimerHandle& InOutHandle, UserClass* InObj, typename FTimerDelegate::TUObjectMethodDelegate_Const< UserClass >::FMethodPtr InTimerMethod, float InRate, bool InbLoop = false, float InFirstDelay = -1.f){InternalSetTimer(InOutHandle, FTimerUnifiedDelegate( FTimerDelegate::CreateUObject(InObj, InTimerMethod) ), InRate, InbLoop, InFirstDelay);}/** Version that takes any generic delegate. */FORCEINLINE void SetTimer(FTimerHandle& InOutHandle, FTimerDelegate const& InDelegate, float InRate, bool InbLoop, float InFirstDelay = -1.f){InternalSetTimer(InOutHandle, FTimerUnifiedDelegate(InDelegate), InRate, InbLoop, InFirstDelay);}/** Version that takes a dynamic delegate (e.g. for UFunctions). */FORCEINLINE void SetTimer(FTimerHandle& InOutHandle, FTimerDynamicDelegate const& InDynDelegate, float InRate, bool InbLoop, float InFirstDelay = -1.f){InternalSetTimer(InOutHandle, FTimerUnifiedDelegate(InDynDelegate), InRate, InbLoop, InFirstDelay);}/*** Version that doesn't take a delegate */FORCEINLINE void SetTimer(FTimerHandle& InOutHandle, float InRate, bool InbLoop, float InFirstDelay = -1.f){InternalSetTimer(InOutHandle, FTimerUnifiedDelegate(), InRate, InbLoop, InFirstDelay);}/** Version that takes a TFunction */FORCEINLINE void SetTimer(FTimerHandle& InOutHandle, TFunction<void(void)>&& Callback, float InRate, bool InbLoop, float InFirstDelay = -1.f ){InternalSetTimer(InOutHandle, FTimerUnifiedDelegate(MoveTemp(Callback)), InRate, InbLoop, InFirstDelay);}

思路一

• Trigger.h

// Fill out your copyright notice in the Description page of Project Settings.#pragma once#include "CoreMinimal.h"
#include "GameFramework/Actor.h"
#include "TriggerDoor.generated.h"UCLASS()
class UEGAME_API ATriggerDoor : public AActor
{GENERATED_BODY()public:	// Sets default values for this actor's propertiesATriggerDoor();UPROPERTY(VisibleAnywhere, BlueprintReadWrite)class UBoxComponent* TriggerBox;UPROPERTY(VisibleAnywhere, BlueprintReadWrite)class UStaticMeshComponent* TriggerMesh;UPROPERTY(VisibleAnywhere, BlueprintReadWrite)UStaticMeshComponent* DoorMesh;//获取门与触发器位置UPROPERTY(BlueprintReadWrite,Category = "Trigger Door|Trigger Properties")FVector InitTriggerLoction;UPROPERTY(BlueprintReadWrite,Category = "Trigger Door|Door Properties")FVector InitDoorLocation;//延时时间UPROPERTY(EditAnywhere, BlueprintReadWrite, Category = "Trigger Door|Trigger Properties")float DelayTimer;//创建一个时间句柄FTimerHandle CloseDoorTimerHandle;protected:// Called when the game starts or when spawnedvirtual void BeginPlay() override;public:	// Called every framevirtual void Tick(float DeltaTime) override;//自定义AddDynamic绑定的触发器函数UFUNCTION()void OnOverlapBegin(UPrimitiveComponent* OverlappedComponent, AActor* OtherActor, UPrimitiveComponent* OtherComp, int32 OtherBodyIndex, bool bFromSweep, const FHitResult& SweepResult);UFUNCTION()void OnOverlapEnd(UPrimitiveComponent* OverlappedComponent, AActor* OtherActor, UPrimitiveComponent* OtherComp, int32 OtherBodyIndex);//将函数提升为事件UFUNCTION(BlueprintImplementableEvent, Category = "Triggerable Dorr|Trigger Switch")void RaiseTrigger();UFUNCTION(BlueprintImplementableEvent, Category = "Triggerable Dorr|Trigger Switch")void LowerTrigger();UFUNCTION(BlueprintImplementableEvent, Category = "Triggerable Dorr|Trigger Switch")void OpenDoor();UFUNCTION(BlueprintImplementableEvent, Category = "Triggerable Dorr|Trigger Switch")void CloseDoor();UFUNCTION(BlueprintCallable,Category="Triggerable Door | Triggerable Switch")void UpdateTriggerLocation(FVector offset);UFUNCTION(BlueprintCallable,Category= "Triggerable Door | Door Switch")void UpdateDoorLocation(FVector offset);
};

• Trigger.cpp

// Fill out your copyright notice in the Description page of Project Settings.#include "TriggerDoor.h"
#include "Components/BoxComponent.h"
#include "Components/StaticMeshComponent.h"
#include "Characters/Player/MainPlayer.h"
#include "TimerManager.h"// Sets default values
ATriggerDoor::ATriggerDoor()
{// Set this actor to call Tick() every frame.  You can turn this off to improve performance if you don't need it.PrimaryActorTick.bCanEverTick = true;TriggerBox = CreateDefaultSubobject<UBoxComponent>(TEXT("TriggerBox"));RootComponent = TriggerBox;TriggerBox->SetBoxExtent(FVector(60.f, 60.f, 30.f));//设置TriggerBox碰撞的硬编码TriggerBox->SetCollisionEnabled(ECollisionEnabled::QueryOnly);//设置碰撞类型TriggerBox->SetCollisionObjectType(ECollisionChannel::ECC_WorldStatic);//设置对象移动时其应视为某种物体TriggerBox->SetCollisionResponseToAllChannels(ECollisionResponse::ECR_Ignore);//设置所有的碰撞响应为忽略TriggerBox->SetCollisionResponseToChannel(ECollisionChannel::ECC_Pawn, ECollisionResponse::ECR_Overlap);//设置Pawn碰撞响应为重叠TriggerMesh = CreateDefaultSubobject<UStaticMeshComponent>(TEXT("TriggerMesh"));TriggerMesh->SetupAttachment(GetRootComponent());DoorMesh = CreateDefaultSubobject<UStaticMeshComponent>(TEXT("DoorMesh"));DoorMesh->SetupAttachment(GetRootComponent());//延迟时间设为2秒DelayTimer = 2.0f;}// Called when the game starts or when spawned
void ATriggerDoor::BeginPlay()
{Super::BeginPlay();TriggerBox->OnComponentBeginOverlap.AddDynamic(this, &ATriggerDoor::OnOverlapBegin);TriggerBox->OnComponentEndOverlap.AddDynamic(this, &ATriggerDoor::OnOverlapEnd);//获取到门和触发器的位置InitTriggerLoction = TriggerMesh->GetComponentLocation();InitDoorLocation = DoorMesh->GetComponentLocation();
}// Called every frame
void ATriggerDoor::Tick(float DeltaTime)
{Super::Tick(DeltaTime);}void ATriggerDoor::OnOverlapBegin(UPrimitiveComponent* OverlappedComponent, AActor* OtherActor, UPrimitiveComponent* OtherComp, int32 OtherBodyIndex, bool bFromSweep, const FHitResult& SweepResult)
{AMainPlayer* Player = Cast<AMainPlayer>(OtherActor);if (Player){//清除定时器GetWorldTimerManager().ClearTimer(CloseDoorTimerHandle);OpenDoor();LowerTrigger();}
}void ATriggerDoor::OnOverlapEnd(UPrimitiveComponent* OverlappedComponent, AActor* OtherActor, UPrimitiveComponent* OtherComp, int32 OtherBodyIndex)
{AMainPlayer* Player = Cast<AMainPlayer>(OtherActor);if (Player){RaiseTrigger();//开启定时器进行关门GetWorldTimerManager().SetTimer(CloseDoorTimerHandle, this, &ATriggerDoor::CloseDoor, DelayTimer);}
}void ATriggerDoor::UpdateTriggerLocation(FVector offset)
{//新位置=初始位置+移动后的位置FVector newLocation = InitTriggerLoction + offset;TriggerMesh->SetWorldLocation(newLocation);
}void ATriggerDoor::UpdateDoorLocation(FVector offset)
{//新位置=初始位置+移动后的位置FVector newLocation = InitDoorLocation + offset;DoorMesh->SetWorldLocation(newLocation);
}

思路二

• 定义一个bool变量用来检测角色是否踩到触发器
• 我们采用Lambda表示来进行操作，使用Lambda表达式操作，SetTimer函数传入参数会不一样

GetWorldTimerManager().SetTimer(CloseDoorTimerHandle, FTimerDelegate::CreateLambda(CloseDoorLambda), DelayTimer, false);

• Trigger.h

// Fill out your copyright notice in the Description page of Project Settings.#pragma once#include "CoreMinimal.h"
#include "GameFramework/Actor.h"
#include "TriggerDoor.generated.h"UCLASS()
class UEGAME_API ATriggerDoor : public AActor
{GENERATED_BODY()public:	// Sets default values for this actor's propertiesATriggerDoor();UPROPERTY(VisibleAnywhere, BlueprintReadWrite)class UBoxComponent* TriggerBox;UPROPERTY(VisibleAnywhere, BlueprintReadWrite)class UStaticMeshComponent* TriggerMesh;UPROPERTY(VisibleAnywhere, BlueprintReadWrite)UStaticMeshComponent* DoorMesh;//获取门与触发器位置UPROPERTY(BlueprintReadWrite,Category = "Trigger Door|Trigger Properties")FVector InitTriggerLoction;UPROPERTY(BlueprintReadWrite,Category = "Trigger Door|Door Properties")FVector InitDoorLocation;//延时时间UPROPERTY(EditAnywhere, BlueprintReadWrite, Category = "Trigger Door|Trigger Properties")float DelayTimer;bool bIsPlayerOnTrigger;//创建一个时间句柄FTimerHandle CloseDoorTimerHandle;protected:// Called when the game starts or when spawnedvirtual void BeginPlay() override;public:	// Called every framevirtual void Tick(float DeltaTime) override;//自定义AddDynamic绑定的触发器函数UFUNCTION()void OnOverlapBegin(UPrimitiveComponent* OverlappedComponent, AActor* OtherActor, UPrimitiveComponent* OtherComp, int32 OtherBodyIndex, bool bFromSweep, const FHitResult& SweepResult);UFUNCTION()void OnOverlapEnd(UPrimitiveComponent* OverlappedComponent, AActor* OtherActor, UPrimitiveComponent* OtherComp, int32 OtherBodyIndex);//将函数提升为事件UFUNCTION(BlueprintImplementableEvent, Category = "Triggerable Dorr|Trigger Switch")void RaiseTrigger();UFUNCTION(BlueprintImplementableEvent, Category = "Triggerable Dorr|Trigger Switch")void LowerTrigger();UFUNCTION(BlueprintImplementableEvent, Category = "Triggerable Dorr|Trigger Switch")void OpenDoor();UFUNCTION(BlueprintImplementableEvent, Category = "Triggerable Dorr|Trigger Switch")void CloseDoor();UFUNCTION(BlueprintCallable,Category="Triggerable Door | Triggerable Switch")void UpdateTriggerLocation(FVector offset);UFUNCTION(BlueprintCallable,Category= "Triggerable Door | Door Switch")void UpdateDoorLocation(FVector offset);
};

• Tirgger.cpp

// Fill out your copyright notice in the Description page of Project Settings.#include "TriggerDoor.h"
#include "Components/BoxComponent.h"
#include "Components/StaticMeshComponent.h"
#include "Characters/Player/MainPlayer.h"
#include "TimerManager.h"// Sets default values
ATriggerDoor::ATriggerDoor()
{// Set this actor to call Tick() every frame.  You can turn this off to improve performance if you don't need it.PrimaryActorTick.bCanEverTick = true;TriggerBox = CreateDefaultSubobject<UBoxComponent>(TEXT("TriggerBox"));RootComponent = TriggerBox;TriggerBox->SetBoxExtent(FVector(60.f, 60.f, 30.f));//设置TriggerBox碰撞的硬编码TriggerBox->SetCollisionEnabled(ECollisionEnabled::QueryOnly);//设置碰撞类型TriggerBox->SetCollisionObjectType(ECollisionChannel::ECC_WorldStatic);//设置对象移动时其应视为某种物体TriggerBox->SetCollisionResponseToAllChannels(ECollisionResponse::ECR_Ignore);//设置所有的碰撞响应为忽略TriggerBox->SetCollisionResponseToChannel(ECollisionChannel::ECC_Pawn, ECollisionResponse::ECR_Overlap);//设置Pawn碰撞响应为重叠TriggerMesh = CreateDefaultSubobject<UStaticMeshComponent>(TEXT("TriggerMesh"));TriggerMesh->SetupAttachment(GetRootComponent());DoorMesh = CreateDefaultSubobject<UStaticMeshComponent>(TEXT("DoorMesh"));DoorMesh->SetupAttachment(GetRootComponent());//延迟时间设为2秒DelayTimer = 2.0f;bIsPlayerOnTrigger = false;
}// Called when the game starts or when spawned
void ATriggerDoor::BeginPlay()
{Super::BeginPlay();TriggerBox->OnComponentBeginOverlap.AddDynamic(this, &ATriggerDoor::OnOverlapBegin);TriggerBox->OnComponentEndOverlap.AddDynamic(this, &ATriggerDoor::OnOverlapEnd);//获取到门和触发器的位置InitTriggerLoction = TriggerMesh->GetComponentLocation();InitDoorLocation = DoorMesh->GetComponentLocation();
}// Called every frame
void ATriggerDoor::Tick(float DeltaTime)
{Super::Tick(DeltaTime);}void ATriggerDoor::OnOverlapBegin(UPrimitiveComponent* OverlappedComponent, AActor* OtherActor, UPrimitiveComponent* OtherComp, int32 OtherBodyIndex, bool bFromSweep, const FHitResult& SweepResult)
{AMainPlayer* Player = Cast<AMainPlayer>(OtherActor);if (Player){//判断主角踩到触发器,就为真if (bIsPlayerOnTrigger == false){bIsPlayerOnTrigger = true;}OpenDoor();LowerTrigger();}
}void ATriggerDoor::OnOverlapEnd(UPrimitiveComponent* OverlappedComponent, AActor* OtherActor, UPrimitiveComponent* OtherComp, int32 OtherBodyIndex)
{AMainPlayer* Player = Cast<AMainPlayer>(OtherActor);//判断主角没踩到触发器,就为假if (bIsPlayerOnTrigger == true){bIsPlayerOnTrigger = false;}//Lambda表达式auto CloseDoorLambda = [this](){//主角没有踩到触发器就关门if (bIsPlayerOnTrigger == false){CloseDoor();}};if(Player){RaiseTrigger();//开启定时器进行关门GetWorldTimerManager().SetTimer(CloseDoorTimerHandle, FTimerDelegate::CreateLambda(CloseDoorLambda), DelayTimer, false);}
}void ATriggerDoor::UpdateTriggerLocation(FVector offset)
{//新位置=初始位置+移动后的位置FVector newLocation = InitTriggerLoction + offset;TriggerMesh->SetWorldLocation(newLocation);
}void ATriggerDoor::UpdateDoorLocation(FVector offset)
{//新位置=初始位置+移动后的位置FVector newLocation = InitDoorLocation + offset;DoorMesh->SetWorldLocation(newLocation);
}

Actor创建一个随机生成空间

• 新建一个Actor类用来随机随机生成Actor，添加触发器与一个模版变量(专门用来存储AActor)

public:	// Sets default values for this actor's propertiesASpawnVolume();//触发器UPROPERTY(VisibleAnywhere, BlueprintReadOnly)class UBoxComponent* SpawnBox;//模版类,用来添加AActorUPROPERTY(EditAnywhere, BlueprintReadOnly, Category = "Spawn Volume")TArray<TSubclassOf<AActor>> SpawnClass;

获取Actor随机位置与随机种类

• 新建两个函数用来获取种类与位置
• 头文件#include “Kismet/KismetMathLibrary.h” 中会有很多数学函数
• 例如：RandomPointInBoundingBox：随机点在边界框

public:	// Called every framevirtual void Tick(float DeltaTime) override;//获取随机位置UFUNCTION(BlueprintCallable, Category = "Spawn Volume")FVector GetSpawnRandomLocation();UFUNCTION(BlueprintCallable, Category = "Spawn Volume")TSubclassOf<AActor> GetSpawnClass();
};

FVector ASpawnVolume::GetSpawnRandomLocation()
{FVector OriginPoint = SpawnBox->GetComponentLocation();FVector Extent = SpawnBox->GetScaledBoxExtent();return UKismetMathLibrary::RandomPointInBoundingBox(OriginPoint,Extent);
}TSubclassOf<AActor> ASpawnVolume::GetSpawnClass()
{if (SpawnClass.Num() > 0){int index = FMath::RandRange(0, SpawnClass.Num() - 1);return SpawnClass[index];}else{return nullptr;}
}

随机生成区域与蓝图本地事件机制

• BlueprintPure参数：可以把函数变成纯净函数没有执行线
• BlueprintNativeEvent参数一般要与BlueprintCallable一起使用，在蓝图中声明的本地事件使用BlueprintNativeEvent关键词进行标记。它告诉Unreal Engine系统该事件可以在C++中进行实现，并且可以在蓝图中被重写或使用。一旦在蓝图中声明了本地事件，就可以在C++中编写实现该事件的代码。通过继承蓝图类的C++类，可以对该本地事件进行重写或添加额外的逻辑。这样，当在蓝图中调用该本地事件时，将执行C++中实现的代码逻辑。总之，BlueprintNativeEvent关键词允许在Unreal Engine蓝图中声明本地事件，并通过C++进行实现和扩展。这样的设计模式提供了蓝图和C++之间的灵活交互，允许开发人员在保持蓝图的简洁性和可视化优势的同时，利用C++的强大功能来实现高级逻辑和性能优化
• 在C++中实现一个蓝图本地事件时，通常需要在函数名后添加_Implementation作为后缀。例如，如果在蓝图中声明了一个本地事件函数MyEvent，那么在C++中实现它的函数名将是MyEvent_Implementation。这是因为在Unreal Engine中，蓝图本地事件的实现通常是通过虚函数重写机制来完成的。当蓝图中调用本地事件时，底层引擎会查找与事件函数同名的_Implementation函数，然后执行该函数中的代码逻辑。使用_Implementation作为后缀是一种约定，用于将原始的虚函数和其实现函数进行区分。这样做可以保持函数名的一致性，并且使代码更易于理解和维护。另外，_Implementation函数是在C++类中实现蓝图本地事件的默认方法。你也可以在自定义C++类中以其他的名字实现蓝图本地事件，只需在蓝图中指定相应的函数即可。
  总结起来，为了实现蓝图本地事件函数，需要在函数名后添加_Implementation作为后缀。这是为了区分虚函数和其实现函数，并保持代码的一致性和清晰度
• GetWorld()->SpawnActor<AActor>(SpawnClasses, SpawnLocation, FRotator(0.0f))：生成Actor在世界中
• SpawnActor：函数源码

	/** Templated version of SpawnActor that allows you to specify a class type via the template type */template< class T >T* SpawnActor( const FActorSpawnParameters& SpawnParameters = FActorSpawnParameters() ){return CastChecked<T>(SpawnActor(T::StaticClass(), NULL, NULL, SpawnParameters),ECastCheckedType::NullAllowed);}/** Templated version of SpawnActor that allows you to specify location and rotation in addition to class type via the template type */template< class T >T* SpawnActor( FVector const& Location, FRotator const& Rotation, const FActorSpawnParameters& SpawnParameters = FActorSpawnParameters() ){return CastChecked<T>(SpawnActor(T::StaticClass(), &Location, &Rotation, SpawnParameters),ECastCheckedType::NullAllowed);}/** Templated version of SpawnActor that allows you to specify the class type via parameter while the return type is a parent class of that type */template< class T >T* SpawnActor( UClass* Class, const FActorSpawnParameters& SpawnParameters = FActorSpawnParameters() ){return CastChecked<T>(SpawnActor(Class, NULL, NULL, SpawnParameters),ECastCheckedType::NullAllowed);}/** *  Templated version of SpawnActor that allows you to specify the rotation and location in addition*  class type via parameter while the return type is a parent class of that type */template< class T >T* SpawnActor( UClass* Class, FVector const& Location, FRotator const& Rotation, const FActorSpawnParameters& SpawnParameters = FActorSpawnParameters() ){return CastChecked<T>(SpawnActor(Class, &Location, &Rotation, SpawnParameters),ECastCheckedType::NullAllowed);}/** *  Templated version of SpawnActor that allows you to specify whole Transform*  class type via parameter while the return type is a parent class of that type */template< class T >T* SpawnActor(UClass* Class, FTransform const& Transform,const FActorSpawnParameters& SpawnParameters = FActorSpawnParameters()){return CastChecked<T>(SpawnActor(Class, &Transform, SpawnParameters), ECastCheckedType::NullAllowed);}

SpawnVolume.h

// Fill out your copyright notice in the Description page of Project Settings.#pragma once#include "CoreMinimal.h"
#include "GameFramework/Actor.h"
#include "SpawnVolume.generated.h"UCLASS()
class UEGAME_API ASpawnVolume : public AActor
{GENERATED_BODY()public:	// Sets default values for this actor's propertiesASpawnVolume();//触发器UPROPERTY(VisibleAnywhere, BlueprintReadOnly)class UBoxComponent* SpawnBox;//模版类,用来添加AActor的子类UPROPERTY(EditAnywhere, BlueprintReadOnly, Category = "Spawn Volume")TArray<TSubclassOf<AActor>> SpawnClass;protected:// Called when the game starts or when spawnedvirtual void BeginPlay() override;public:	// Called every framevirtual void Tick(float DeltaTime) override;//获取随机位置UFUNCTION(BlueprintPure, Category = "Spawn Volume")FVector GetSpawnRandomLocation();UFUNCTION(BlueprintPure, Category = "Spawn Volume")TSubclassOf<AActor> GetSpawnClass();//蓝图本地事件机制UFUNCTION(BlueprintNativeEvent, BlueprintCallable, Category = "Spawn Volue")void SpawnActor(UClass* SpawnClasses, FVector SpawnLocation);
};

SpawnVolume.cpp

// Fill out your copyright notice in the Description page of Project Settings.#include "SpawnVolume.h"
#include "Components/BoxComponent.h"
#include "Kismet/KismetMathLibrary.h"
// Sets default values
ASpawnVolume::ASpawnVolume()
{// Set this actor to call Tick() every frame.  You can turn this off to improve performance if you don't need it.PrimaryActorTick.bCanEverTick = true;SpawnBox = CreateDefaultSubobject<UBoxComponent>(TEXT("SpawnBox"));RootComponent = SpawnBox;}// Called when the game starts or when spawned
void ASpawnVolume::BeginPlay()
{Super::BeginPlay();}// Called every frame
void ASpawnVolume::Tick(float DeltaTime)
{Super::Tick(DeltaTime);}FVector ASpawnVolume::GetSpawnRandomLocation()
{FVector OriginPoint = SpawnBox->GetComponentLocation();FVector Extent = SpawnBox->GetScaledBoxExtent();return UKismetMathLibrary::RandomPointInBoundingBox(OriginPoint,Extent);
}TSubclassOf<AActor> ASpawnVolume::GetSpawnClass()
{if (SpawnClass.Num() > 0){int index = FMath::RandRange(0, SpawnClass.Num() - 1);return SpawnClass[index];}else{return 0;}
}
//生成Actor
void ASpawnVolume::SpawnActor_Implementation(UClass* SpawnClasses, FVector SpawnLocation)
{GetWorld()->SpawnActor<AActor>(SpawnClasses, SpawnLocation, FRotator(0.0f));
}

• 蓝图中去调用写好的这个机制
  
• 运行结果
  

Actor创建移动浮空平台

创建移动平台与EditWidget工具

• 创建一个Actor类，这个Actor需要一个静态网格，两个变量(一个表示起点一个表示终点)
• meta = (EditWidget = “true”)：这是一个可选的元标记（Metadata），用于添加额外的属性信息。在这种情况下，MakeEditWidget 被设置为 “true”，这表示该属性可以在编辑器中作为一个小部件进行编辑。这通常用于自定义编辑器小部件以提供更直观的属性编辑体验。

public:	// Sets default values for this actor's propertiesAFloatingPlatform();UPROPERTY(VisibleAnywhere,BlueprintReadOnly)class UStaticMeshComponent* PlatformMesh;UPROPERTY(VisibleAnywhere, Category = "Floating Platform")FVector StartPoint{};UPROPERTY(EditAnywhere, Category = "Floating Platform", meta = (MakeEditWidget = "true"))FVector EndPoint{};

• 运行结果
  

使用VInterpTo进行插值

• 新建一个变量PlatformSpeed用来设置上升速度

public:	// Sets default values for this actor's propertiesAFloatingPlatform();UPROPERTY(VisibleAnywhere,BlueprintReadOnly)class UStaticMeshComponent* PlatformMesh;UPROPERTY(VisibleAnywhere, Category = "Floating Platform")FVector StartPoint{};UPROPERTY(EditAnywhere, Category = "Floating Platform", meta = (MakeEditWidget = "true"))FVector EndPoint{};UPROPERTY(EditAnywhere, Category = "Floating Platform")float PlatformSpeed;

• 使用VInterpTo进行移动
• VInterpTo 源码

CORE_API FVector FMath::VInterpTo( const FVector& Current, const FVector& Target, float DeltaTime, float InterpSpeed )
{// If no interp speed, jump to target valueif( InterpSpeed <= 0.f ){return Target;}// Distance to reachconst FVector Dist = Target - Current;// If distance is too small, just set the desired locationif( Dist.SizeSquared() < KINDA_SMALL_NUMBER ){return Target;}// Delta Move, Clamp so we do not over shoot.const FVector	DeltaMove = Dist * FMath::Clamp<float>(DeltaTime * InterpSpeed, 0.f, 1.f);return Current + DeltaMove;
}

• VInterpConstantTo：匀速运动源码

CORE_API FVector FMath::VInterpConstantTo(const FVector Current, const FVector& Target, float DeltaTime, float InterpSpeed)
{const FVector Delta = Target - Current;const float DeltaM = Delta.Size();const float MaxStep = InterpSpeed * DeltaTime;if( DeltaM > MaxStep ){if( MaxStep > 0.f ){const FVector DeltaN = Delta / DeltaM;return Current + DeltaN * MaxStep;}else{return Current;}}return Target;
}

• FloatingPlatform.cpp

// Fill out your copyright notice in the Description page of Project Settings.#include "FloatingPlatform.h"
#include "Components/StaticMeshComponent.h"
// Sets default values
AFloatingPlatform::AFloatingPlatform()
{// Set this actor to call Tick() every frame.  You can turn this off to improve performance if you don't need it.PrimaryActorTick.bCanEverTick = true;PlatformMesh = CreateDefaultSubobject<UStaticMeshComponent>(TEXT("Platform"));RootComponent = PlatformMesh;PlatformSpeed = 2.f;
}// Called when the game starts or when spawned
void AFloatingPlatform::BeginPlay()
{Super::BeginPlay();//获取Actor的世界位置StartPoint = GetActorLocation();EndPoint += StartPoint;
}// Called every frame
void AFloatingPlatform::Tick(float DeltaTime)
{Super::Tick(DeltaTime);FVector CurrentLocation = GetActorLocation();FVector NewLocation = FMath::VInterpTo(CurrentLocation, EndPoint, DeltaTime, PlatformSpeed);SetActorLocation(NewLocation);//移动到新位置
}

使用定时器进行平台来回移动

• 新建一个bool变量bInterping用来判断是否要开启定时器，新建一个DelayTime用来规定延时时间几秒后开启定时器，新键一个用来记录当前位置的变量Distance
• 思路：bInterping默认为true，Distance获取到移动到目标点的位置，在移动过程中，新建一个NewDistace获取当前世界位置减去开始位置的值，判断Distance要是减去NewDistance的值大于等于一个很小的值，就说明到最终位置了，此时的bInterping为false了，该开启定时器返回起点，2秒后定时器中函数表达式bInterping为真，互换起点与终点位置，又进行新一轮平台移动

FloatingPlatform.h

// Fill out your copyright notice in the Description page of Project Settings.#pragma once#include "CoreMinimal.h"
#include "GameFramework/Actor.h"
#include "FloatingPlatform.generated.h"UCLASS()
class UEGAME_API AFloatingPlatform : public AActor
{GENERATED_BODY()public:	// Sets default values for this actor's propertiesAFloatingPlatform();UPROPERTY(VisibleAnywhere,BlueprintReadOnly)class UStaticMeshComponent* PlatformMesh;UPROPERTY(VisibleAnywhere, Category = "Floating Platform")FVector StartPoint{};UPROPERTY(EditAnywhere, Category = "Floating Platform", meta = (MakeEditWidget = "true"))FVector EndPoint{};UPROPERTY(EditAnywhere, Category = "Floating Platform")float PlatformSpeed;UPROPERTY(EditAnywhere, Category = "Floating Platform")float DelayTime;FTimerHandle InterpTimerHandle;bool bInterping;float Distance;
protected:// Called when the game starts or when spawnedvirtual void BeginPlay() override;public:	// Called every framevirtual void Tick(float DeltaTime) override;};

FloatingPlatform.cpp

// Fill out your copyright notice in the Description page of Project Settings.#include "FloatingPlatform.h"
#include "Components/StaticMeshComponent.h"
#include "TimerManager.h"
// Sets default values
AFloatingPlatform::AFloatingPlatform()
{// Set this actor to call Tick() every frame.  You can turn this off to improve performance if you don't need it.PrimaryActorTick.bCanEverTick = true;PlatformMesh = CreateDefaultSubobject<UStaticMeshComponent>(TEXT("PlatformMesh"));RootComponent = PlatformMesh;PlatformSpeed = 200.f;DelayTime = 2.0f;bInterping = true;
}// Called when the game starts or when spawned
void AFloatingPlatform::BeginPlay()
{Super::BeginPlay();//获取Actor的世界位置StartPoint = GetActorLocation();Distance = EndPoint.Size();EndPoint += StartPoint;}// Called every frame
void AFloatingPlatform::Tick(float DeltaTime)
{Super::Tick(DeltaTime);if (bInterping){FVector CurrentLocation = GetActorLocation();FVector NewLocation = FMath::VInterpConstantTo(CurrentLocation, EndPoint, DeltaTime, PlatformSpeed);SetActorLocation(NewLocation);//移动到新位置float NewDistance = (GetActorLocation() - StartPoint).Size();if (Distance - NewDistance <= 0.5f){bInterping = !bInterping;//Lambda表达式auto ToggleInterpState = [this](){bInterping = !bInterping;};//开启定时器GetWorldTimerManager().SetTimer(InterpTimerHandle, FTimerDelegate::CreateLambda(ToggleInterpState), DelayTime, false);//交换起点与终点FVector temp = StartPoint;StartPoint = EndPoint;EndPoint = temp;}}}

• 运行结果