StateTree Evaluator Instance in Condition data is NULL

[ajinkya_x]

I’m using State Tree in my C++ code.

NPC is always null in Condition while in task its available.

USTRUCT()
struct WAREHOUSEBOI_API FIsAtSpawnLocationConditionInstance
{
	GENERATED_BODY()

	UPROPERTY(VisibleAnywhere, Category = "Output")
	TWeakObjectPtr<ATruckDriverNPC> NPC;
};
USTRUCT(meta = (DisplayName = "Is At Spawn Location"))
struct WAREHOUSEBOI_API FIsAtSpawnLocationCondition : public FStateTreeConditionCommonBase
{
    GENERATED_BODY()

	using FInstanceDataType = FIsAtSpawnLocationConditionInstance;

    virtual bool TestCondition(FStateTreeExecutionContext& Context) const override;
    virtual const UStruct* GetInstanceDataType() const override { return FIsAtSpawnLocationConditionInstance::StaticStruct(); }

    UPROPERTY(EditAnywhere, Category = "Parameters")
    float AcceptanceRadius = 10.0f;
};

// CPP

bool FIsAtSpawnLocationCondition::TestCondition(FStateTreeExecutionContext& Context) const
{
    const FIsAtSpawnLocationConditionInstance& Instance = Context.GetInstanceData<FIsAtSpawnLocationConditionInstance>(*this);
    const ATruckDriverNPC* NPC = Instance.NPC.Get();
    if (!NPC) return false;

    const float DistanceToSpawn = FVector::Distance(NPC->GetActorLocation(), NPC->SpawnPosition);
    return DistanceToSpawn <= AcceptanceRadius;
}

As you can see in the below State Tree Details panel I have assigned NPC in Task which I got from the Evaluator context.

Evaluator:

evaluator header:

USTRUCT()
struct WAREHOUSEBOI_API FTruckDriverNPCEvaluatorInstance
{
	GENERATED_BODY()

	UPROPERTY(VisibleAnywhere, Category = "Output")
	TWeakObjectPtr<ATruckDriverNPC> NPC;
};

/**
* Evaluator that provides NPC reference to all State Tree tasks and conditions
* This runs once at State Tree startup and makes the NPC available everywhere
*/
USTRUCT(meta = (DisplayName = "Truck Driver NPC Reference"))
struct WAREHOUSEBOI_API FTruckDriverNPCEvaluator : public FStateTreeEvaluatorCommonBase
{
	GENERATED_BODY()

	virtual void TreeStart(FStateTreeExecutionContext& Context) const override;

	virtual const UStruct* GetInstanceDataType() const override
	{
		return FTruckDriverNPCEvaluatorInstance::StaticStruct();
	}
};

evaluator cpp

/*
* 1. Runs once at State Tree startup
  2. Gets the owner actor (your NPC)
  3. Stores reference in the evaluator instance
  4. All tasks/conditions can access this reference through their instance data
 */
void FTruckDriverNPCEvaluator::TreeStart(FStateTreeExecutionContext& Context) const
{
	FTruckDriverNPCEvaluatorInstance& Evaluator = Context.GetInstanceData<FTruckDriverNPCEvaluatorInstance>(*this);

	// Get the Actor that owns this State Tree Component
	AActor* Owner = Cast<AActor>(Context.GetOwner());
	if (!Owner)
	{
		UE_LOG(LogTemp, Error, TEXT("FTruckDriverNPCEvaluator::TreeStart: No Actor found for State Tree Component."));
		return;
	}

	Evaluator.NPC = Cast<ATruckDriverNPC>(Owner);
	if (!Evaluator.NPC.IsValid())
	{
		UE_LOG(LogTemp, Error, TEXT("FTruckDriverNPCEvaluator: Owner is not a TruckDriverNPC"));
	} else
	{
		UE_LOG(LogTemp, Warning, TEXT("FTruckDriverNPCEvaluator: Successfully bound to NPC %s"), *Evaluator.NPC->GetName());
	}
}