Initialization of the ASC where the pawn is the owner and the avatar actor might be redundant

[gaurang-ingale]

Hello @tranek, thanks again for this treasure of a repo!

While going through it for a new project I am working on, I found that the initialization part of the ASC might be redundant when the Owner and Avatar Actors are the same object which the ASC is a member of. The reason being the function below (as of UE 5.7.0):

void UAbilitySystemComponent::InitializeComponent()
{
	Super::InitializeComponent();

	// Look for DSO AttributeSets (note we are currently requiring all attribute sets to be subobjects of the same owner. This doesn't *have* to be the case forever.
	AActor *Owner = GetOwner();
	InitAbilityActorInfo(Owner, Owner);	// Default init to our outer owner

	// cleanup any bad data that may have gotten into SpawnedAttributes
	for (int32 Idx = SpawnedAttributes.Num()-1; Idx >= 0; --Idx)
	{
		if (SpawnedAttributes[Idx] == nullptr)
		{
			SpawnedAttributes.RemoveAt(Idx);
		}
	}

	TArray<UObject*> ChildObjects;
	GetObjectsWithOuter(Owner, ChildObjects, false, RF_NoFlags, EInternalObjectFlags::Garbage);

	for (UObject* Obj : ChildObjects)
	{
		UAttributeSet* Set = Cast<UAttributeSet>(Obj);
		if (Set)  
		{
			SpawnedAttributes.AddUnique(Set);
		}
	}

	SetSpawnedAttributesListDirty();
}

This function belongs to AActor and is overriden by the ASC as it is by most component classes and the initialization already occurs here. As this function will run on both, the server and the client, it becomes unnecessary to have to call InitAbilityActorInfo on the ASC again, unless either the Owner and/or Avatar Actors have changed.

Do you think it would make sense to note this in the documentation in Section 4.1.2?

[ameaninglessname]

PlayerController might not be ready when InitializeComponent

[gaurang-ingale]

PlayerController might not be ready when InitializeComponent

@ameaninglessname, what do you mean? I don't quite follow.

InitializeComponent will be called by both the client and the server on all of the Character's Actor components. And UAbilitySystemComponent::InitializeComponent is calling InitAbilityActorInfo(Owner, Owner); // Default init to our outer owner.

So where does PlayerController even matter in this if the ASC lives on the Character and the Character is both the OwnerActor AND the AvatarActor?

I am referring to this part of the documentation by the way:

The ASC needs to be initialized with its OwnerActor and AvatarActor on both the server and the client. You want to initialize after the Pawn's Controller has been set (after possession). Single player games only need to worry about the server path.

For player controlled characters where the ASC lives on the Pawn, I typically initialize on the server in the Pawn's PossessedBy() function and initialize on the client in the PlayerController's AcknowledgePossession() function.

void APACharacterBase::PossessedBy(AController * NewController)
{
	Super::PossessedBy(NewController);

	if (AbilitySystemComponent)
	{
		AbilitySystemComponent->InitAbilityActorInfo(this, this);
	}

	// ASC MixedMode replication requires that the ASC Owner's Owner be the Controller.
	SetOwner(NewController);
}

void APAPlayerControllerBase::AcknowledgePossession(APawn* P)
{
	Super::AcknowledgePossession(P);

	APACharacterBase* CharacterBase = Cast<APACharacterBase>(P);
	if (CharacterBase)
	{
		CharacterBase->GetAbilitySystemComponent()->InitAbilityActorInfo(CharacterBase, CharacterBase);
	}

	//...
}