这一部分学习了怎么创建一个伤害性的地形(火焰地形,毒沼泽等都可以用这个方式创建)

AuraEffectActor.h

// Fill out your copyright notice in the Description page of Project Settings.

#pragma once

#include "CoreMinimal.h"
#include "GameplayEffect.h"
#include "AbilitySystem/AuraAbilitySystemComponentBase.h"
#include "Components/SphereComponent.h"
#include "GameFramework/Actor.h"
#include "GameplayEffectTypes.h"
#include "AuraEffectActor.generated.h"

class UGameplayEffect;
class UAbilitySystemComponent;

UENUM(BlueprintType)
enum class EEffectApplicationPolicy : uint8 { ApplyOnOverlap,ApplyOnEndOverlap,DoNotApply  };

UENUM(BlueprintType)
enum class EEffectRemovePolicy : uint8 { RemoveOnEndOverlap,DoNotRemove  };

UCLASS()
class MYGAS_API AAuraEffectActor : public AActor
{
   GENERATED_BODY()
   
public:    
   // Sets default values for this actor's properties
   AAuraEffectActor();
   
protected:
   // Called when the game starts or when spawned
   virtual void BeginPlay() override;

   UFUNCTION(BlueprintCallable)
   void ApplyEffectToTarget(AActor* TargetActor, TSubclassOf<UGameplayEffect> GameplayEffectClass);

   UFUNCTION(BlueprintCallable)
   void OnOverlap(AActor* TargetActor);

   UFUNCTION(BlueprintCallable)
   void OnEndOverlap(AActor* TargetActor);
   
   UPROPERTY(EditAnywhere,BlueprintReadOnly,Category="Applied Effects")
   TSubclassOf<UGameplayEffect> InstantGameplayEffectClass;

   UPROPERTY(EditAnywhere,BlueprintReadOnly,Category="Applied Effects")
   EEffectApplicationPolicy  InstantEffectApplicationPolicy = EEffectApplicationPolicy::DoNotApply;
      
   UPROPERTY(EditAnywhere,BlueprintReadOnly,Category="Applied Effects")
   TSubclassOf<UGameplayEffect> DurationGameplayEffectClass;

   UPROPERTY(EditAnywhere,BlueprintReadOnly,Category="Applied Effects")
   EEffectApplicationPolicy  DurationEffectApplicationPolicy = EEffectApplicationPolicy::DoNotApply;
   
   UPROPERTY(EditAnywhere,BlueprintReadOnly,Category="Applied Effects")
   TSubclassOf<UGameplayEffect> InfiniteGameplayEffectClass;

   UPROPERTY(EditAnywhere,BlueprintReadOnly,Category="Applied Effects")
   EEffectApplicationPolicy  InfiniteEffectApplicationPolicy = EEffectApplicationPolicy::DoNotApply;

   UPROPERTY(EditAnywhere,BlueprintReadOnly,Category="Applied Effects")
   EEffectRemovePolicy InfiniteEffectRemovePolicy = EEffectRemovePolicy::RemoveOnEndOverlap;

   TMap<FActiveGameplayEffectHandle , UAbilitySystemComponent*> ActiveEffectHandles;
private:
   
};

AuraEffectActor.cpp

 // Fill out your copyright notice in the Description page of Project Settings.


#include "Actor/AuraEffectActor.h"

#include "AbilitySystemBlueprintLibrary.h"
#include "AbilitySystemComponent.h"
#include "AbilitySystemInterface.h"
#include "AbilitySystem/AuraAbilitySystemComponentBase.h"
#include "AbilitySystem/AuraAttributeSet.h"
#include "Components/StaticMeshComponent.h"

 // Sets default values
AAuraEffectActor::AAuraEffectActor()
{
 // Set this actor to call Tick() every frame.  You can turn this off to improve performance if you don't need it.
   PrimaryActorTick.bCanEverTick = false;
   SetRootComponent(CreateDefaultSubobject<USceneComponent>("SceneRoot"));
}

 // Called when the game starts or when spawned
void AAuraEffectActor::BeginPlay()
{
   Super::BeginPlay();
 
}

void AAuraEffectActor::ApplyEffectToTarget(AActor* TargetActor, TSubclassOf<UGameplayEffect> GameplayEffectClass)
{
   //这里是使用 UAbilitySystemBlueprintLibrary 内的静态函数,在指定的Target上查找并返回UAbilitySystemComponent
   UAbilitySystemComponent* TargetASC =  UAbilitySystemBlueprintLibrary::GetAbilitySystemComponent(TargetActor);
   if(TargetASC==nullptr) return;

   check(GameplayEffectClass);
   //创建了一个游戏效果的内容句柄,提供游戏效果的信息
   FGameplayEffectContextHandle TargetASCContext =TargetASC->MakeEffectContext();
   //把自己作为游戏效果的源对象,确保AbilitySystem可以识别到自己
   TargetASCContext.AddSourceObject(this);
   //这里创建了一个游戏效果规范,GameplayEffectClass 是要应用的游戏效果的类,1.0f 是游戏效果的初始生命周期倍率,TargetASCContext 是游戏效果的上下文. 调用 MakeOutgoingSpec 函数，将会根据提供的参数创建一个游戏效果规范
   const FGameplayEffectSpecHandle EffectSpecHandle = TargetASC->MakeOutgoingSpec(GameplayEffectClass,1.0f,TargetASCContext);
   const FActiveGameplayEffectHandle ActiveGameplayEffectHandle =  TargetASC->ApplyGameplayEffectSpecToSelf(*EffectSpecHandle.Data.Get());

   const bool bIsInfinite = EffectSpecHandle.Data.Get()->Def.Get()->DurationPolicy == EGameplayEffectDurationType::Infinite;
   if(bIsInfinite)
   {
      ActiveEffectHandles.Add(ActiveGameplayEffectHandle,TargetASC);
   }
}

void AAuraEffectActor::OnOverlap(AActor* TargetActor)
{
    if(InstantEffectApplicationPolicy == EEffectApplicationPolicy::ApplyOnOverlap)
    {
      ApplyEffectToTarget(TargetActor,InstantGameplayEffectClass);
    }
    if(DurationEffectApplicationPolicy == EEffectApplicationPolicy::ApplyOnOverlap)
    {
     ApplyEffectToTarget(TargetActor,DurationGameplayEffectClass);
    }
    if(InfiniteEffectApplicationPolicy == EEffectApplicationPolicy::ApplyOnOverlap)
    {
     ApplyEffectToTarget(TargetActor,InfiniteGameplayEffectClass);
    }
}

void AAuraEffectActor::OnEndOverlap(AActor* TargetActor)
{
    if(InstantEffectApplicationPolicy == EEffectApplicationPolicy::ApplyOnOverlap)
    {
     ApplyEffectToTarget(TargetActor,InstantGameplayEffectClass);
    }
    if(DurationEffectApplicationPolicy == EEffectApplicationPolicy::ApplyOnOverlap)
    {
     ApplyEffectToTarget(TargetActor,DurationGameplayEffectClass);
    }
    if(InfiniteEffectApplicationPolicy == EEffectApplicationPolicy::ApplyOnOverlap)
    {
     ApplyEffectToTarget(TargetActor,InfiniteGameplayEffectClass);
    }
    if(InfiniteEffectRemovePolicy == EEffectRemovePolicy::RemoveOnEndOverlap)
    {
        //获取到目标角色的能力组件
        UAbilitySystemComponent* TargetASC = UAbilitySystemBlueprintLibrary::GetAbilitySystemComponent(TargetActor);
        if(!IsValid(TargetASC)) return;
        //创建了一个储存移除游戏效果句柄的数组 HandlesToRemove
        TArray<FActiveGameplayEffectHandle> HandlesToRemove;
        //遍历 ActiveEffectHandles 数组
        for(TTuple<FActiveGameplayEffectHandle, UAbilitySystemComponent*> HandlePair:ActiveEffectHandles)
        {
             // 当 TargetASC 内有 HandlePair.Value的值的时候
             if(TargetASC == HandlePair.Value)
             {
                 // 移除 HandlePair 的效果
                 TargetASC->RemoveActiveGameplayEffect(HandlePair.Key, 1);
                 //把这个效果放在 HandlesToRemove 中
                 HandlesToRemove.Add(HandlePair.Key);
             }
        }
        // 遍历 HandlesToRemove 内的每一个元素
        for(auto& Handle : HandlesToRemove)
        {
             // 在 ActiveEffectHandles 这个数组内移除
             ActiveEffectHandles.FindAndRemoveChecked(Handle);
             
        }
    }
 }
 
      

创建GE_FireArea和BP_FireArea

FireArea需要把Applied Effects设置喂Apply Overlay