UE5 笔记二 GameplayAbilitySystem Attributes & Effects

摘要：本文介绍了在虚幻引擎中创建基础属性集(UBasicAttributeSet)的实现过程，包含生命值(Health/MaxHealth)和耐力值(Stamina/MaxStamina)属性的定义。通过UCLASS宏和UPROPERTY标记实现属性的蓝图访问和网络复制功能，使用ATTRIBUTE_ACCESSORS_BASIC宏简化属性访问。文章还涉及游戏效果(GameplayEffect)的创建和应用机制，解释了添加效果使用ApplyGameplayEffectToSelf节点，而移除效果则采用RemoveActiveEffectsWithGrantedTags节点的设计逻辑：前者针对具体效果，后者关注状态清除。最后提到如何为技能添加冷却和消耗效果，并手动触发这些游戏效果。

Result Image:

Q: Read with some questions

1. 为什么Gameplayability 中有cooldown 和 Costs 插槽,但是没有 StaminaRegen 插槽

GameplayAbility = 一次"行为 / 动作 / 技能"

👉 Cooldown / Cost 是"一次性行为"的规则

👉 StaminaRegen 是"持续状态"，不属于 Ability 本身

2.在角色添加 耐力值回复 的功能中,为啥 添加 node 叫ApplyGameplayEffectToSelf,移除却叫 Remove Active Effects with Granted Tags?

Tip:

加的时候你知道"加谁"

删的时候你只关心"不要什么状态"

Apply：以"具体 Effect"为中心

Remove：以"状态 / 结果"为中心

3. 为什么 GE_state_staminaregen stacking limit count =1

GE_State_StaminaRegen 的 Stacking Limit Count = 1

是为了防止"重复 Apply 导致回体力叠加"

Cost 和Cooldown 不用本身就是一次性的

1. Create BasicAttributeSet C++ Class

#pragma once

#include "CoreMinimal.h"
#include "AttributeSet.h"
#include "AbilitySystemComponent.h"
#include "BasicAttributeSet.generated.h"

/**
 * 
 */
UCLASS()
class GAS_API UBasicAttributeSet : public UAttributeSet
{
	GENERATED_BODY()
	
public:
	UBasicAttributeSet();
	
	// 生命值属性					
	UPROPERTY(BlueprintReadOnly, Category = "Attributes",ReplicatedUsing = OnRep_Health)
	FGameplayAttributeData Health;
	ATTRIBUTE_ACCESSORS_BASIC(UBasicAttributeSet, Health);
	
	// 最大生命值属性
	UPROPERTY(BlueprintReadOnly, Category = "Attributes",ReplicatedUsing = OnRep_MaxHealth)
	FGameplayAttributeData MaxHealth;
	ATTRIBUTE_ACCESSORS_BASIC(UBasicAttributeSet, MaxHealth);
	
	// Stamina Attribute
	UPROPERTY(BlueprintReadOnly, Category = "Attributes",ReplicatedUsing = OnRep_Stamina)
	FGameplayAttributeData Stamina;
	ATTRIBUTE_ACCESSORS_BASIC(UBasicAttributeSet, Stamina);
	
	// MaxStamina Attribute
	UPROPERTY(BlueprintReadOnly, Category = "Attributes",ReplicatedUsing = OnRep_MaxStamina)
	FGameplayAttributeData MaxStamina;
	ATTRIBUTE_ACCESSORS_BASIC(UBasicAttributeSet, MaxStamina);
	
public: 
	UFUNCTION()
	void OnRep_Health(const FGameplayAttributeData& OldValue) const
	{
		GAMEPLAYATTRIBUTE_REPNOTIFY(UBasicAttributeSet, Health, OldValue);
	};
	
	UFUNCTION()
	void OnRep_MaxHealth(const FGameplayAttributeData& OldValue) const
	{
		GAMEPLAYATTRIBUTE_REPNOTIFY(UBasicAttributeSet, MaxHealth, OldValue);
	};
	
	UFUNCTION()
	void OnRep_Stamina(const FGameplayAttributeData& OldValue) const
	{
		GAMEPLAYATTRIBUTE_REPNOTIFY(UBasicAttributeSet, Stamina, OldValue);
	};
	
	UFUNCTION()
	void OnRep_MaxStamina(const FGameplayAttributeData& OldValue) const
	{
		GAMEPLAYATTRIBUTE_REPNOTIFY(UBasicAttributeSet, MaxStamina, OldValue);
	};
	
	virtual  void GetLifetimeReplicatedProps(TArray<FLifetimeProperty>& OutLifetimeProps) const override;
};

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


#include "BasicAttributeSet.h"

#include "Net/UnrealNetwork.h"

UBasicAttributeSet::UBasicAttributeSet()
{
	// 初始化属性值
	Health = 100.f;
	MaxHealth = 100.f;
	Stamina = 100.f;
	MaxStamina = 100.f;
}

void UBasicAttributeSet::GetLifetimeReplicatedProps(TArray<FLifetimeProperty>& OutLifetimeProps) const
{
	Super::GetLifetimeReplicatedProps(OutLifetimeProps);

	DOREPLIFETIME_CONDITION_NOTIFY(UBasicAttributeSet, Health, COND_None, REPNOTIFY_Always);
	DOREPLIFETIME_CONDITION_NOTIFY(UBasicAttributeSet, MaxHealth, COND_None, REPNOTIFY_Always);
	DOREPLIFETIME_CONDITION_NOTIFY(UBasicAttributeSet, Stamina, COND_None, REPNOTIFY_Always);
	DOREPLIFETIME_CONDITION_NOTIFY(UBasicAttributeSet, MaxStamina, COND_None, REPNOTIFY_Always);
}

2. Create Three GameplayEffect Blueprint Class

Has Duration Cooldown 必须是 Has Duration，因为"冷却"本质就是一段时间

Instant 立刻扣除25的耐力值

Infinite 无限制,只要存在就是一直按照(1/30)秒执行一次当前Effect

3. Add Cooldown Effect & Cost Effect to Ability' Attribute

4. Manual invocation Gameplay Effects