Retrieve Behavior Tree without using Blue Print

Development Programming & Scripting AI
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I followed the [Behavior Tree Quick Start Guide][1] and got everything to work simply enough.

I’m now trying to convert the Follower_AI_CON controller from a Blue Print to C++ but I can’t get a reference to the Behaviour Tree (using only C++).

I’m able to get a reference by creating a Blue Print that has a parent class of AIController and selecting my Behaviour Tree from within the editor (image below) but that seems wasteful considering I won’t be using the Blue Print for anything other than that tiny dropdown menu.

I’ve spent a frustrating number of hours on what appears to be a simple task. I guess I’m not as smart as I lead people to believe! :smiley:

My bare-bones .h / .cpp files look like this:

.h

UCLASS()
class THIRDPERSON_API AAIController : public AAIController
{
	GENERATED_BODY()

	ATPAIController(const class FObjectInitializer& ObjectInitializer);

public:

	virtual void Possess(class APawn* InPawn) override;

	// Reference to the AI's blackboard component.
	UPROPERTY(EditAnywhere, BlueprintReadWrite, Category = "AI")
	UBlackboardComponent* BlackboardComponent;

	// The Behavior Tree Component used by this AI.
	UPROPERTY(EditAnywhere, BlueprintReadWrite, Category = "AI")
	UBehaviorTreeComponent* BehaviorTreeComponent;

	UPROPERTY(EditDefaultsOnly, Category = "AI")
	class UBehaviorTree* BehaviorTree;

};

.cpp

AAIController::AAIController(const FObjectInitializer& ObjectInitializer) : Super(ObjectInitializer)
{
	BlackboardComponent = ObjectInitializer.CreateDefaultSubobject<UBlackboardComponent>(this, TEXT("EnemyAIBlackboard"));
	BehaviorTreeComponent = ObjectInitializer.CreateDefaultSubobject<UBehaviorTreeComponent>(this, TEXT("EnemyAIBehaviorTree"));
}

void AAIController::Possess(APawn* InPawn)
{
	Super::Possess(InPawn);

	if (BehaviorTree)
	{
		BlackboardComponent->InitializeBlackboard(*BehaviorTree->BlackboardAsset);
		BehaviorTreeComponent->StartTree(*BehaviorTree, EBTExecutionMode::Looped);
	}
}