说明

AI / EQS / Find Ammo Pickup

寻找弹药补给的EQS: EQS_FindAmmoPickup

判断是否需要领取弹药补给的Decorator类名STUNeedAmmoDecorator

指定武器类型, 自然弹药不是无限模式, 而这里暂时设置为当弹药耗尽才去领取补给

要求武器类型和弹药补给类型一致

可以参考上节当作练习, 再和给出的答案进行比较

创建EQS资产并测试

预备工作

1. 设置弹药补给材质为黑色
   

   • 双击打开 Content/Pickups/BP_STUAmmoPickup
     
   • 内容浏览器选中 Content/Materials/M_BaseColor
     
   • 应用材质
     

   

   
   

2. 拖动复制弹药补给为3个
   

   

   
   

3. 确保发射器的弹药不是无限模式
   
   BP_STULauncherWeapon > Default Ammo > Infinite , 取消勾选
   

   

   
   

创建EQS资产, 命名为EQS_FindAmmoPickup

Content/AI/EQS 目录下

可以使用Ctrl-W对EQS_FindHealthPickup进行拷贝, 并修改筛选Actor类型

设置EQS_TestPawn应用EQS_FindAmmoPickup, 查看

Details > EQS > Query Template , 选择EQS_FindAmmoPickup

添加生成器: 设置补给类型

Generators > Actors Of Class

-
Searched Actor Class	指定Actor类型	STUAmmoPickup
Search Radius	搜索半径	1500

为生成器添加限制条件: 视线可见

Add Test > Trace

要求无阻挡

-
Filter > Bool Match	取消勾选

为生成器添加限制条件: 距离最近

Add Test > Distance

-
Filter > Filter Type	Minimum
Filter > Float Value Min	0
Score > Scoring Factor	-1	距离越近, 权重越大

为生成器添加限制条件: 存在可到达路径

Add Test > Path Finding

在行为树中使用EQS资产

1. 暂时停止当前逻辑
   

2. 添加节点: Selector
   
   NPC寻找弹药补给, 或等待
   

3. 添加节点: Wait
   
   设置时长为2s
   

4. 添加序列
   

5. 为序列添加任务: RunEQSQuery
   

6. 设置EQS
   

   • Details > EQS > EQSRequest > Query Template , 设置为EQS_FindAmmoPickup
     
   • Details > Blackboard > Blackboard Key , 设置为AimLocation
     

   

   
   

7. 为序列添加任务: MoveTo
   
   Details > Blackboard > Blackboard Key , 设置为AimLocation
   

   

   
   

查看

1. 按下 F8 或者点击 Eject
   
2. 拖动距离NPC最近的弹药补给: NPC寻找并去到此时距离最近的弹药补给位置
   
3. 点击 Pause simulation , 将所有弹药补给移动到墙后, 点击 Resume play-in-editor session
   
   序列停止, NPC循环执行Wait任务
   

实现STUNeedAmmoDecorator

创建C++类

-
基类	BTDecorator
名称	STUNeedAmmoDecorator
路径	AI/Decorators
属性	Public

武器组件添加接口: 指定类型武器弹药是否为空

课程中只要检测到弹药不是满的, 就会去领取弹药补给; 为此, 将ASTUBaseWeapon::IsAmmoFull从protected移动到public

public

ShootThemUp: Components/STUWeaponComponent.h

Copy1bool IsAmmoEmpty(TSubclassOf<ASTUBaseWeapon> WeaponType) const;

ShootThemUp: Components/STUWeaponComponent.cpp

Copy 1bool USTUWeaponComponent::IsAmmoEmpty(TSubclassOf<ASTUBaseWeapon> WeaponType) const
 2{
 3    for (const auto Weapon : Weapons)
 4    {
 5        if (Weapon && Weapon->IsA(WeaponType))
 6        {
 7            return Weapon->IsAmmoEmpty();
 8        }
 9    }
10    return false;
11}

添加构造函数

public

ShootThemUp: AI/Decorators/STUNeedAmmoDecorator.h

Copy1USTUNeedAmmoDecorator();

ShootThemUp: AI/Decorators/STUNeedAmmoDecorator.cpp

Copy1USTUNeedAmmoDecorator::USTUNeedAmmoDecorator()
2{
3    NodeName = "Need Ammo";
4}

添加属性: 设置武器类型

protected

ShootThemUp: AI/Decorators/STUNeedAmmoDecorator.h

Copy1class ASTUBaseWeapon;
2
3UPROPERTY(EditAnywhere, BlueprintReadWrite)
4TSubclassOf<ASTUBaseWeapon> WeaponType;

覆写条件

protected

ShootThemUp: AI/Decorators/STUNeedAmmoDecorator.h

Copy1virtual bool CalculateRawConditionValue(UBehaviorTreeComponent& OwnerComp, uint8* NodeMemory) const override;

参考拾取弹药逻辑: 要求游戏角色存活

ShootThemUp: Pickups/STUAmmoPickup.cpp

GivePickupTo

ShootThemUp: AI/Decorators/STUNeedAmmoDecorator.cpp

Copy 1#include "Weapon/STUBaseWeapon.h"
 2#include "AIController.h"
 3#include "STUUtils.h"
 4#include "Components/STUHealthComponent.h"
 5#include "Components/STUWeaponComponent.h"
 6
 7bool USTUNeedAmmoDecorator::CalculateRawConditionValue(UBehaviorTreeComponent& OwnerComp, uint8* NodeMemory) const
 8{
 9    const auto Controller = OwnerComp.GetAIOwner();
10    if (!Controller) return false;
11
12    const auto HealthComponent = STUUtils::GetSTUPlayerComponent<USTUHealthComponent>(Controller->GetPawn());
13    if (!HealthComponent || HealthComponent->IsDead()) return false;
14
15    const auto WeaponComponent = STUUtils::GetSTUPlayerComponent<USTUWeaponComponent>(Controller->GetPawn());
16    if (!WeaponComponent) return false;
17
18    return WeaponComponent->IsAmmoEmpty(WeaponType);
19}

使用STUNeedAmmoDecorator

BT_STUCharacter

1. 为Sequence添加Decorator
   

2. 设置STUHealthPercentDecorator
   

   -
   Observer aborts	Self
   Weapon Type	BP_STULauncherWeapon

   

   
   

调整行为树

由于弹药初始不为空, 需要射击逻辑

1. 将本节新建序列移动到拾取生命补给逻辑之后: 优先级其次
   

2. 恢复行为树框架
   

3. 确保射击服务有目标
   

   

   
   

4. 暂时不更换武器
   

   

   
   

5. 步枪伤害设为0
   
   BP_STURifleWeapon > Damage Amount
   

   

   
   

6. 可以在拾取生命补给和拾取弹药补给移动之前添加Wait任务, 用来判断NPC发现补给情况
   

   

   
   

恢复设置

• 更换武器
  
• 弹药补给材质