How to spawn a Blueprint from C++?

Development Programming & Scripting Blueprint
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1

Hello,

I know that there have been a few similar questions, but all doesn’t work for me. It’s extremely frustrating to spawn something in UE4. My code:

in h.

TSubclassOf<class AActor> BHGrenade;

in cpp constructor:

static ConstructorHelpers::FObjectFinder<UBlueprint> ZSFSGrenadeBlackHawkBP(TEXT("Blueprint'/Game/AI_Weapons/BlackHawk/SpawnBlackHawk/ZSFSGrenadeBlackHawk.ZSFSGrenadeBlackHawk'"));
	if (ZSFSGrenadeBlackHawkBP.Object){
		
		BHGrenade = Cast<UClass>(ZSFSGrenadeBlackHawkBP.Object->GeneratedClass);
		
	}

in function:

AActor* Grenade = GetWorld()->SpawnActor<AActor>(BHGrenade->GetClass());

I get an error:

LogSpawn:Warning: SpawnActor failed because Blueprint is not an actor class
2

So, if you expose the object type to the editor in some way, you can assign that blueprint class type over to whatever you’re trying to spawn.

Weapon.h
UPROPERTY(EditDefaultsOnly, BlueprintReadOnly, Category = "Weapon Properties")
TSubclassOf<class ABaseProjectile>  ProjectileType;

Weapon.cpp
ABaseProjectile* Projectile = Cast<ABaseProjectile>(UGameplayStatics::BeginDeferredActorSpawnFromClass(this, ProjectileType, SpawnTM));

// Modify projectile settings

UGameplayStatics::FinishSpawningActor(Projectile, SpawnTM);

Then in the editor, you can browse whatever class you want to set for the class type
.

3

You’re retrieving the class from a UClass when you attempt to spawn the actor. A UClass’s class is not an AActor.

In your constructor you’re getting the class you want, and storing it in your BHGrenade property:

if (ZSFSGrenadeBlackHawkBP.Object){
         
    BHGrenade = Cast<UClass>(ZSFSGrenadeBlackHawkBP.Object->GeneratedClass);
         
}

BHGrendade is now the class you want to use to spawn. You don’t need to GetClass from it, it is the class.

Here you’re spawning a object with the class of your class:

AActor* Grenade = GetWorld()->SpawnActor<AActor>(BHGrenade->GetClass());

Try this instead:

AActor* Grenade = GetWorld()->SpawnActor<AActor>(BHGrenade);
4

Thank you!

I haven’t seen such a method for spawning.

5

I need just that! Thank you very much!