Default Actor Components

In Unreal Engine, actors can be composed of multiple components that represent physical parts of the object, such as meshes, cameras, or lights.

Setting a Root Component

Every actor needs a root component, which serves as the parent for all other components in the actor’s hierarchy. The root component defines the actor’s position, rotation, and scale in the world.

To define a root component using UnrealSharp, you use the [UProperty] attribute with the DefaultComponent and RootComponent flags set to true:

[UProperty(DefaultComponent = true, RootComponent = true)]
public USceneComponent MyRootComponent { get; set; }

• DefaultComponent: This flag indicates that the property should be automatically instantiated as a component when the actor is created.

• RootComponent: Setting this flag to true designates this component as the root component of the actor.

Attaching More Components

Once the root component is set, you can begin attaching other components. A common requirement is to attach a visual representation to your actor, like a static mesh.

To attach a component as a child of the root component, use the AttachmentComponent parameter to specify the parent component’s name:

[UProperty(DefaultComponent = true, AttachmentComponent = nameof(MyRootComponent))]
public UStaticMeshComponent MyStaticMeshComponent { get; set; }

You can also attach components to another component’s socket:

[UProperty(DefaultComponent = true, AttachmentComponent = nameof(MyRootComponent), AttachmentSocket = "MySocketName")]
public USkeletalMeshComponent MySkeletalMeshComponent { get; set; }