GetWorld()->SpawnActor() not spawn actors

Development Programming & Scripting
1

Hi, anyone can help?
When I pressed the Fire1 key, I want the game to spawn a projectile, but it never working.

UPROPERTY(VisibleAnywhere, BlueprintReadWrite, Category = "Turret")
		TSubclassOf<AActor> Projectile;


// Handle input
			const FTankInput & CurrentInput = Tank->GetCurrentInput();
			if (CurrentInput.bFire1 && Projectile)
			{
				if (UWorld * World = GetWorld())
				{
					float CurrentTime = World->GetTimeSeconds();
					if (Fire1ReadyTime <= CurrentTime)
					{						
						FVector Loc = TurretSprite->GetSocketLocation(MuzzleSocketName);
						FRotator Rot = TurretDirection->GetComponentRotation();
						if (AActor* NewProjectile = World->SpawnActor(Projectile))
						{
							NewProjectile->SetActorLocation(Loc);
							NewProjectile->SetActorRotation(Rot);
						}
						// Set the cooldown time.
						Fire1ReadyTime = CurrentTime + Fire1Cooldown;
					}
				}
			}

I was binding the Fire1 key with this function:

void ATank::SetupPlayerInputComponent(class UInputComponent* InputComponent)
{
Super::SetupPlayerInputComponent(InputComponent);

InputComponent->BindAxis("MoveX", this, &ATank::MoveX);
InputComponent->BindAxis("MoveY", this, &ATank::MoveY);
InputComponent->BindAction("Fire1", EInputEvent::IE_Pressed, this, &ATank::Fire1Pressed);
InputComponent->BindAction("Fire1", EInputEvent::IE_Released, this, &ATank::Fire1Released);
InputComponent->BindAction("Fire2", EInputEvent::IE_Pressed, this, &ATank::Fire2Pressed);
InputComponent->BindAction("Fire2", EInputEvent::IE_Released, this, &ATank::Fire2Released);

}

2

Hey Dream_luo,

Instead of if (AActor* NewProjectile = World->SpawnActor(Projectile))

Try doing this::

AActor* NewProjectile = World->SpawnActor(Projectile)
if(NewProjectile)
{
     .....
}
3

I’m sorry for the delay.It worked.And I want to ask another question.I have a class inherit from AActor class, But I can’t use SpawnActor() to spawn it, how to do this?

4

Here’s a link to our documentation for this. It will show you how to set it up:

5

This documentation is very useful, but when I spawn an actor in another class, editor always crash, how to fix it?
Here’s my code:

UPROPERTY(VisibleAnywhere, BlueprintReadOnly, Category = "Projectile")
    		class AProjectile* Missile;
    void ASpawnTestCharacter::SetupPlayerInputComponent(class UInputComponent* PlayerInputComponent)
    {
    	// Set up gameplay key bindings
    	check(PlayerInputComponent);
  
    	PlayerInputComponent->BindAction("Attack", IE_Pressed, this, &ASpawnTestCharacter::Fire);
    }
    
    
    void ASpawnTestCharacter::Fire()
    {
    	FVector Loc = GetActorForwardVector() * 50;
    	FRotator Rot = GetActorRotation();
    	AProjectile* NewMissile = GetWorld()->SpawnActor<AProjectile>(Missile->GetClass());
    	NewMissile->SetActorLocation(Loc);
    	NewMissile->SetActorRotation(Rot);
    }
6

Glad you were able to use the documentation to get something set up.

 void ASpawnTestCharacter::Fire()
     {
         FVector Loc = GetActorForwardVector() * 50;
         FRotator Rot = GetActorRotation();
         AProjectile* NewMissile = GetWorld()->SpawnActor<AProjectile>(Missile->GetClass(), Loc, Rot);

        if(NewMissile)
        {
            UE_LOG(LogTemp, Warning, TEXT("Actor spawned successfully));
        }

     }

So I added the SetActorLocation and SetActorRotation into the spawn parameters, which you can do if you take a look at the documentation. It just saves you a bit of writing.

Also, I did a check to see if the Missile spawned successfully, and logged a message so this will tell you if there is an issue with the spawning.

7

It’s very useful, and it worked.Maybe I often crash because there is no set Spawn Location and Rotation.Thank you very much.