Unreal 4引擎中，使用BehaviorTree控制AI行为的C++实现

#include "Tooth.h" #include "Guide.h" #include "GuideController.h" #include "BehaviorTree/BehaviorTree.h" #include "BehaviorTree/BehaviorTreeComponent.h" #include "BehaviorTree/BlackboardComponent.h" #include "BehaviorTree/Blackboard/BlackboardKeyAllTypes.h" AGuideController::AGuideController(const class FObjectInitializer& ObjectInitializer) : Super(ObjectInitializer), PreDestinationActor(nullptr), PreTurnToActor(nullptr) { BehaviorTreeComponent = ObjectInitializer.CreateDefaultSubobject<UBehaviorTreeComponent>(this, TEXT("BehaviorTree")); BlackboardComponent = ObjectInitializer.CreateDefaultSubobject<UBlackboardComponent>(this, TEXT("Blackboard")); } void AGuideController::Possess(APawn* InPawn) { Super::Possess(InPawn); AGuide* Guide = Cast<AGuide>(InPawn); if (Guide) { if (Guide->BehaviorTree) { if (Guide->BehaviorTree->BlackboardAsset) { BlackboardComponent->InitializeBlackboard(*Guide->BehaviorTree->BlackboardAsset); BehaviorTreeComponent->StartTree(*Guide->BehaviorTree); } else { UE_LOG(GuideLog, Error, TEXT(LOG_HEADER"No blackboard is assigned to the guide's behavior tree.")); } } else { UE_LOG(GuideLog, Error, TEXT(LOG_HEADER"No behavior tree is assigned to guide.")); } } else { UE_LOG(GuideLog, Error, TEXT(LOG_HEADER"The pawn possessed is not an instance of AGuide.")); } } void AGuideController::UnPossess() { Super::UnPossess(); BehaviorTreeComponent->StopTree(); } void AGuideController::GuideMoveToActor(AActor* DestinationActor, AActor* TurnToActor, float RelativeDistance) { if (BlackboardComponent) { BlackboardComponent->SetValueAsFloat(RelativeDistanceKeyName, RelativeDistance); if (!BlackboardComponent->GetValueAsBool(MoveToActorKeyName)) { if (!PreDestinationActor || !DestinationActor->GetActorLabel().Equals(PreDestinationActor->GetActorLabel())) { PreDestinationActor = DestinationActor; BlackboardComponent->SetValueAsObject(DestinationActorKeyName, DestinationActor); BlackboardComponent->SetValueAsObject(TurnToActorKeyName, TurnToActor); BlackboardComponent->SetValueAsBool(MoveToActorKeyName, true); } } } } void AGuideController::GuideMoveToLocation(FVector DestinationLocation, AActor* TurnToActor, float RelativeDistance) { if (BlackboardComponent) { BlackboardComponent->SetValueAsFloat(RelativeDistanceKeyName, RelativeDistance); if (!BlackboardComponent->GetValueAsBool(MoveToLocationKeyName)) { BlackboardComponent->SetValueAsVector(DestinationLocationKeyName, DestinationLocation); BlackboardComponent->SetValueAsObject(TurnToActorKeyName, TurnToActor); BlackboardComponent->SetValueAsBool(MoveToLocationKeyName, true); } } } void AGuideController::GuideTurnTo(AActor* TurnToActor, float RelativeAngle) { if (BlackboardComponent) { BlackboardComponent->SetValueAsFloat(RelativeAngleKeyName, RelativeAngle); if (!BlackboardComponent->GetValueAsBool(TurnKeyName)) { if (!PreTurnToActor || !TurnToActor->GetActorLabel().Equals(PreTurnToActor->GetActorLabel())) { PreTurnToActor = TurnToActor; BlackboardComponent->SetValueAsObject(TurnToActorKeyName, TurnToActor); BlackboardComponent->SetValueAsBool(TurnKeyName, true); } } } } void AGuideController::GuidePlayAudio(FString AudioName) { if (BlackboardComponent) { BlackboardComponent->SetValueAsString(AudioNameKeyName, AudioName); if (!BlackboardComponent->GetValueAsBool(PlayAudioKeyName)) { BlackboardComponent->SetValueAsBool(PlayAudioKeyName, true); } } } void AGuideController::GuideStopPlayAudio() { if (BlackboardComponent) { BlackboardComponent->SetValueAsBool(StopPlayAudioKeyName, true); } }