生成随机点, 并设置到黑板变量

说明

• 派生自C++类BTTaskNode
  
• 依赖模块 GameplayTasks 和 NavigationSystem
  

在构造函数中设置任务名

STUNextLocationTask

Copy1USTUNextLocationTask::USTUNextLocationTask()
2{
3    NodeName = "Next Location";
4}

任务逻辑

原型

Copy1virtual EBTNodeResult::Type ExecuteTask(UBehaviorTreeComponent& OwnerComp, uint8* NodeMemory);

返回值

• 成功
  

  Copy1return EBTNodeResult::Succeeded;

• 失败
  

  Copy1return EBTNodeResult::Failed;

生成随机点

Copy 1#include "AIController.h"
 2#include "NavigationSystem.h"
 3
 4const auto Controller = OwnerComp.GetAIOwner();
 5if (!Controller) return EBTNodeResult::Failed;
 6
 7const auto Pawn = Controller->GetPawn();
 8if (!Pawn) return EBTNodeResult::Failed;
 9
10const auto NavSys = UNavigationSystemV1::GetCurrent(Pawn);
11if (!NavSys) return EBTNodeResult::Failed;
12
13FNavLocation NavLocation;
14const auto Found = NavSys->GetRandomReachablePointInRadius(Pawn->GetActorLocation(), 1000, NavLocation);
15if (!Found) return EBTNodeResult::Failed;

设置黑板变量

• 添加属性: 存放黑板变量信息
  

  Copy1UPROPERTY(EditAnywhere, BlueprintReadWrite)
  2FBlackboardKeySelector AimLocationKey;

• 设置黑板变量
  

  Copy1#include "BehaviorTree/BlackboardComponent.h"
  2
  3const auto Blackboard = OwnerComp.GetBlackboardComponent();
  4if (!Blackboard) return EBTNodeResult::Failed;
  5Blackboard->SetValueAsVector(AimLocationKey.SelectedKeyName, NavLocation.Location);

完整实现

Copy 1#include "BehaviorTree/BlackboardComponent.h"
 2#include "AIController.h"
 3#include "NavigationSystem.h"
 4
 5EBTNodeResult::Type USTUNextLocationTask::ExecuteTask(UBehaviorTreeComponent &OwnerComp, uint8 *NodeMemory)
 6{
 7    const auto Controller = OwnerComp.GetAIOwner();
 8    const auto Blackboard = OwnerComp.GetBlackboardComponent();
 9    if (!Controller || !Blackboard) return EBTNodeResult::Failed;
10
11    const auto Pawn = Controller->GetPawn();
12    if (!Pawn) return EBTNodeResult::Failed;
13
14    const auto NavSys = UNavigationSystemV1::GetCurrent(Pawn);
15    if (!NavSys) return EBTNodeResult::Failed;
16
17    FNavLocation NavLocation;
18    const auto Found = NavSys->GetRandomReachablePointInRadius(Pawn->GetActorLocation(), 1000, NavLocation);
19    if (!Found) return EBTNodeResult::Failed;
20
21    Blackboard->SetValueAsVector(AimLocationKey.SelectedKeyName, NavLocation.Location);
22    return EBTNodeResult::Succeeded;
23}

在行为树中使用该任务

添加黑板变量

BB_STUCharacter

设置行为树

• 添加节点: Next Location ; 设置待设置黑板变量
  

  

  
  

• 添加节点: Move To ; 设置目的黑板变量
  

  

  
  

• 完整行为树