How SetupAttachment works?

anonymous_user_9ae3803b1 · September 27, 2019, 4:35pm

from https://docs.unrealengine.com/en-US/Programming/Tutorials/Components/index.html, this code is in the constructor:

USpringArmComponent* SpringArm = CreateDefaultSubobject<USpringArmComponent>(TEXT("CameraAttachmentArm"));
SpringArm->SetupAttachment(RootComponent);

How can unreal keep track of SpringArm? because SpringArm is declare here, it is not a class member.
Is it somehow make a copy of SpringArm and set it up with RootComponent?

Herr_Edgy · September 27, 2019, 6:46pm

As you guessed, the SpringArm is being attached to the RootComponent.
Since the you are inheriting from AActor, your child actor class already has a RootComponent and it does not need to be specified in its members.