Default Actor Components

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 partial 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 partial UStaticMeshComponent MyStaticMeshComponent { get; set; }

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

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

Overriding Native Components

UnrealSharp allows you to swap out default native components (like the standard Character Movement component) with your own custom class, by using the OverrideComponent attribute on a AActor class.

[UClass]
public partial class UMyMovementComponent : UCharacterMovementComponent
{
}

[UClass]

// 1. Your custom class.
// 2. The name of the property that has the native component.
// 3. Optional custom property name to fetch the overridden component directly without casting.
[OverrideComponent(typeof(UMyMovementComponent), nameof(CharacterMovement), "MyMovementComponent")]
public partial class AMyCharacter : ACharacter
{
    public override void BeginPlay()
    {
        // Use the generated "MyMovementComponent" property directly!
        PrintString(MyMovementComponent.GetType().ToString(), 5);
        base.BeginPlay();
    }
}