Section 13: The Enemy Class - Lecture 277

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Config/DefaultInput.ini

@@ -86,11 +86,11 @@ DoubleClickTime=0.200000
 +ActionMappings=(ActionName="Aiming",bShift=False,bCtrl=False,bAlt=False,bCmd=False,Key=RightMouseButton)
 +ActionMappings=(ActionName="Aiming",bShift=False,bCtrl=False,bAlt=False,bCmd=False,Key=Gamepad_LeftTrigger)
 +ActionMappings=(ActionName="Select",bShift=False,bCtrl=False,bAlt=False,bCmd=False,Key=E)
-+ActionMappings=(ActionName="Select",bShift=False,bCtrl=False,bAlt=False,bCmd=False,Key=Gamepad_FaceButton_Right)
++ActionMappings=(ActionName="Select",bShift=False,bCtrl=False,bAlt=False,bCmd=False,Key=Gamepad_FaceButton_Top)
 +ActionMappings=(ActionName="Reload",bShift=False,bCtrl=False,bAlt=False,bCmd=False,Key=R)
 +ActionMappings=(ActionName="Reload",bShift=False,bCtrl=False,bAlt=False,bCmd=False,Key=Gamepad_FaceButton_Left)
 +ActionMappings=(ActionName="Crouch",bShift=False,bCtrl=False,bAlt=False,bCmd=False,Key=C)
-+ActionMappings=(ActionName="Crouch",bShift=False,bCtrl=False,bAlt=False,bCmd=False,Key=Gamepad_RightThumbstick)
++ActionMappings=(ActionName="Crouch",bShift=False,bCtrl=False,bAlt=False,bCmd=False,Key=Gamepad_FaceButton_Right)
 +ActionMappings=(ActionName="FKey",bShift=False,bCtrl=False,bAlt=False,bCmd=False,Key=F)
 +ActionMappings=(ActionName="1Key",bShift=False,bCtrl=False,bAlt=False,bCmd=False,Key=One)
 +ActionMappings=(ActionName="2Key",bShift=False,bCtrl=False,bAlt=False,bCmd=False,Key=Two)
@@ -114,5 +114,6 @@ DoubleClickTime=0.200000
 DefaultPlayerInputClass=/Script/EnhancedInput.EnhancedPlayerInput
 DefaultInputComponentClass=/Script/EnhancedInput.EnhancedInputComponent
 DefaultTouchInterface=/Engine/MobileResources/HUD/DefaultVirtualJoysticks.DefaultVirtualJoysticks
-+ConsoleKeys=Tilde
+-ConsoleKeys=Tilde
++ConsoleKeys=`
 

Shooter.uproject

@@ -9,7 +9,8 @@
 			"Type": "Runtime",
 			"LoadingPhase": "Default",
 			"AdditionalDependencies": [
-				"Engine"
+				"Engine",
+				"AIModule"
 			]
 		}
 	],

Source/Shooter/Enemy.cpp

@@ -7,6 +7,10 @@
 #include "Kismet/GameplayStatics.h"
 #include "Sound/SoundCue.h"
 #include "Particles/ParticleSystemComponent.h"
+#include "Kismet/KismetMathLibrary.h"
+#include "DrawDebugHelpers.h"
+#include "EnemyController.h"
+#include "BehaviorTree/BlackboardComponent.h"
 
 // Sets default values
 AEnemy::AEnemy() :
@@ -28,6 +32,19 @@ void AEnemy::BeginPlay()
 	Super::BeginPlay();
 
 	GetMesh()->SetCollisionResponseToChannel(ECollisionChannel::ECC_Visibility, ECollisionResponse::ECR_Block);
+
+	// Get the AI Controller
+	EnemyController = Cast<AEnemyController>(GetController());
+	
+	const FVector WorldPatrolPoint = UKismetMathLibrary::TransformLocation(GetActorTransform(), PatrolPoint);
+	DrawDebugSphere(GetWorld(), WorldPatrolPoint, 25.f, 12, FColor::Red, true);
+
+	if (EnemyController)
+	{
+		EnemyController->GetBlackboardComponent()->SetValueAsVector("PatrolPoint", WorldPatrolPoint);
+		EnemyController->RunBehaviorTree(BehaviorTree);
+	}
+	
 }
 
 void AEnemy::ShowHealthBar_Implementation()

Source/Shooter/Enemy.h

@@ -10,6 +10,8 @@
 class UParticleSystem;
 class USoundCue;
 class UAnimMontage;
+class UBehaviorTree;
+class AEnemyController;
 
 UCLASS()
 class SHOOTER_API AEnemy : public ACharacter, public IBulletHitInterface
@@ -91,6 +93,16 @@ private:
 	/** Time before a hit number is removed from the screen */
 	UPROPERTY(EditAnywhere, BlueprintReadWrite, Category = Combat, meta = (AllowPrivateAccess = true))
 	float HitNumberDestroyTime;
+
+	/** Behavior tree for the AI Character */
+	UPROPERTY(EditAnywhere, Category = "Behavior Tree", meta = (AllowPrivateAccess = true))
+	UBehaviorTree* BehaviorTree;
+
+	/** Point for the enemy to move to */
+	UPROPERTY(EditAnywhere, Category = "Behavior Tree", meta = (AllowPrivateAccess = true, MakeEditWidget = true))
+	FVector PatrolPoint;
+
+	AEnemyController* EnemyController;
 public:	
 	// Called every frame
 	virtual void Tick(float DeltaTime) override;
@@ -106,4 +118,6 @@ public:
 
 	UFUNCTION(BlueprintImplementableEvent)
 	void ShowHitNumber(int32 Damage, FVector HitLocation, bool bHeadshot);
+	
+	FORCEINLINE UBehaviorTree* GetBehaviorTree() const { return BehaviorTree; }
 };

Source/Shooter/EnemyController.cpp

@@ -0,0 +1,33 @@
+// Fill out your copyright notice in the Description page of Project Settings.
+
+
+#include "EnemyController.h"
+
+#include "Enemy.h"
+#include "BehaviorTree/BehaviorTree.h"
+#include "BehaviorTree/BehaviorTreeComponent.h"
+#include "BehaviorTree/BlackboardComponent.h"
+
+AEnemyController::AEnemyController()
+{
+	BlackboardComponent = CreateDefaultSubobject<UBlackboardComponent>(TEXT("BlackboardComponent"));
+	check(BlackboardComponent);
+
+	BehaviorTreeComponent = CreateDefaultSubobject<UBehaviorTreeComponent>(TEXT("BehaviorTreeComponent"));
+	check(BehaviorTreeComponent);
+}
+
+void AEnemyController::OnPossess(APawn* InPawn)
+{
+	Super::OnPossess(InPawn);
+
+	if (!InPawn) return;
+
+	if (AEnemy* Enemy = Cast<AEnemy>(InPawn))
+	{
+		if (Enemy->GetBehaviorTree())
+		{
+			BlackboardComponent->InitializeBlackboard(*(Enemy->GetBehaviorTree()->BlackboardAsset));
+		}
+	}
+}

Source/Shooter/EnemyController.h

@@ -0,0 +1,34 @@
+// Fill out your copyright notice in the Description page of Project Settings.
+
+#pragma once
+
+#include "CoreMinimal.h"
+#include "AIController.h"
+#include "EnemyController.generated.h"
+
+class UBlackboardComponent;
+class UBehaviorTreeComponent;
+
+/**
+ * 
+ */
+UCLASS()
+class SHOOTER_API AEnemyController : public AAIController
+{
+	GENERATED_BODY()
+public:
+	AEnemyController();
+	virtual void OnPossess(APawn* InPawn) override;
+
+private:
+	/** Blackboard component for this enemy */
+	UPROPERTY(BlueprintReadWrite, Category = "AI Behavior", meta = (AllowPrivateAccess = true))
+	UBlackboardComponent* BlackboardComponent;
+	
+	/** BehaviorTree component for this enemy */
+	UPROPERTY(BlueprintReadWrite, Category = "AI Behavior", meta = (AllowPrivateAccess = true))
+	UBehaviorTreeComponent* BehaviorTreeComponent;
+
+public:
+	FORCEINLINE UBlackboardComponent* GetBlackboardComponent() const { return BlackboardComponent; }
+};

Source/Shooter/Shooter.Build.cs

@@ -8,7 +8,7 @@ public class Shooter : ModuleRules
 	{
 		PCHUsage = PCHUsageMode.UseExplicitOrSharedPCHs;
 	
-		PublicDependencyModuleNames.AddRange(new string[] { "Core", "CoreUObject", "Engine", "InputCore", "UMG", "PhysicsCore" });
+		PublicDependencyModuleNames.AddRange(new string[] { "Core", "CoreUObject", "Engine", "InputCore", "UMG", "PhysicsCore", "NavigationSystem", "AIModule" });
 
 		PrivateDependencyModuleNames.AddRange(new string[] {  });