SpawnSystemAttached + RootComponent + C++ = Problem

[Ivan3z]

I’m spawning a niagara particle system.
And I think I have a problem with the RootComponent.

When I do it in blueprint everything works fine.

When I do it in C++ the system doesn’t spawn

I have tried to do it at location instead of attached and it also works correctly.

So my conclusion is that there must be a problem with the Root component… Or maybe the SpawnSystemAttached() function is failing…

So these are the components that my actor has.

Anybody knows what could be the problem?

Thank you so much!!

[Ivan3z]

The problem seems to be the attach function:
The problem is exactly the same if it is done in this other way.

So I think there must be some problem with attaching a UNiagaraComponent to a USceneComponent.

Must be a problem that blueprints solve under the hood.

Does anyone know how to do it?

[3dRaven]

Implementation for actor MyActor. Don’t forget to replace YOUR_API with own.

Header

	// Fill out your copyright notice in the Description page of Project Settings.

#pragma once

#include "CoreMinimal.h"
#include "GameFramework/Actor.h"
#include "MyActor.generated.h"

UCLASS()
class YOUR_API AMyActor : public AActor
{
	GENERATED_BODY()
	
public:	

	AMyActor();

protected:
	// Called when the game starts or when spawned
	virtual void BeginPlay() override;

public:	

	virtual void Tick(float DeltaTime) override;


	UPROPERTY()
	class UAudioComponent* ShootingAudioComponent;

	UPROPERTY()
	class UAudioComponent* ImpactAudioComponent;
	
	UPROPERTY(EditAnywhere, BlueprintReadWrite)		
	TObjectPtr<class UNiagaraSystem> NiagaraShootingStar;

	UPROPERTY(EditAnywhere, BlueprintReadWrite)
	class UNiagaraComponent* ShootingStarNiagaraSystem;
	
};

cpp

#include "MyActor.h"
#include "Components/AudioComponent.h"
#include "NiagaraFunctionLibrary.h" 
#include "NiagaraSystem.h" 
#include "NiagaraComponent.h" 


AMyActor::AMyActor()
{

	PrimaryActorTick.bCanEverTick = true;
	

	ShootingAudioComponent = CreateDefaultSubobject<UAudioComponent>(TEXT("Shooting Audio"));
	SetRootComponent(ShootingAudioComponent);

	ImpactAudioComponent = CreateDefaultSubobject<UAudioComponent>(TEXT("Impact Audio"));
	ImpactAudioComponent->SetupAttachment(ShootingAudioComponent);

	ShootingStarNiagaraSystem = CreateDefaultSubobject<UNiagaraComponent>(TEXT("UNiagara Component Shooting Star"));
	ShootingStarNiagaraSystem->SetupAttachment(ShootingAudioComponent);
}

// Called when the game starts or when spawned
void AMyActor::BeginPlay()
{
	Super::BeginPlay();
	
	FVector Location = GetActorLocation();
	FRotator Rotation = GetActorRotation();

	ShootingStarNiagaraSystem = UNiagaraFunctionLibrary::SpawnSystemAttached(NiagaraShootingStar,
		GetRootComponent(), "", Location, Rotation, EAttachLocation::KeepRelativeOffset, true, true,
		ENCPoolMethod::AutoRelease, true);

}

// Called every frame
void AMyActor::Tick(float DeltaTime)
{
	Super::Tick(DeltaTime);

}

[Ivan3z]

Thank you very much for your help.