斯坦福UE4 C++课学习补充23：AI自定义任务

news2024/9/27 21:29:22

文章目录

一、自定义任务节点
二、优化
- 1. 子弹发射冷却
- 2. 攻击时面朝玩家

一、自定义任务节点

本节需要创建自定义任务节点BTTask，实现小兵进入角色范围后进射击的功能。
对于BTTaskNode的子类，我们需要在代码中重写ExecuteTask函数即可。返回值为EBTNodeResult::Failed和EBTNodeResult::Successd，对应行为树的节点返回失败或者成功。

//SBTTask_RangeAttack.h
UCLASS()
class FPSPROJECT_API USBTTask_RangeAttack : public UBTTaskNode
{
   GENERATED_BODY()
protected:
   virtual EBTNodeResult::Type ExecuteTask(UBehaviorTreeComponent& OwnerComp, uint8* NodeMemory) override;
   
   //用于角色发射投掷物攻击
   UPROPERTY(EditAnywhere, Category = "AI")
   TSubclassOf<AActor> ProjectileClass;
};


//SBTTask_RangeAttack.cpp
EBTNodeResult::Type USBTTask_RangeAttack::ExecuteTask(UBehaviorTreeComponent& OwnerComp, uint8* NodeMemory)
{
	AAIController* MyController = OwnerComp.GetAIOwner();
	if(ensure(MyController))
	{
		ACharacter* MyPawn = Cast<ACharacter>(MyController->GetPawn());
		if(MyPawn == nullptr)
		{
			return EBTNodeResult::Failed;
		}

		AActor* TargetActor = Cast<AActor>(OwnerComp.GetBlackboardComponent()->GetValueAsObject("TargetActor"));
		if(TargetActor == nullptr)
		{
			return EBTNodeResult::Failed;
		}

		FVector MuzzleLocation = MyPawn->GetMesh()->GetSocketLocation("Muzzle_01");
		//方向向量=目标位置-当前位置
		FVector Direction = TargetActor->GetActorLocation() - MuzzleLocation;
		FRotator MuzzleRotation = Direction.Rotation();

		FActorSpawnParameters params;
		params.Instigator = MyPawn;
		params.SpawnCollisionHandlingOverride = ESpawnActorCollisionHandlingMethod::AlwaysSpawn;

		ensure(ProjectileClass);
		AActor* NewProj = GetWorld()->SpawnActor<AActor>(ProjectileClass, MuzzleLocation, MuzzleRotation);
		return NewProj ? EBTNodeResult::Succeeded : EBTNodeResult::Failed;
	}

	return EBTNodeResult::Failed;
}