Legacy/Actor Components, Making Native & Deferred Attached to Socket

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Overview

Author: Rama (talk)

Dear Community,

Here is my complete code sample for creating and attaching native C++ actor components!

Nativecomp.jpg

Deferred Attachment

This code follows the Deferred Attachment model, whereby you pick a name and a socket, but the actual attachment occurs after the Character Blueprint has also initialized.

(blueprints are not yet setup during the C++ constructor, and their values cannot be relied on)

.h

    //JoyControl
TSubobjectPtr<UStaticMeshComponent> JoyfulControl;
UStaticMesh * AssetSM_JoyControl;
	
FORCEINLINE void SetupSMComponentsWithCollision(UStaticMeshComponent* Comp)
{
	if(!Comp) return;
	//~~~~~~~~
		
	Comp->bOwnerNoSee = false;
	Comp->bCastDynamicShadow = true;
	Comp->CastShadow = true;
	Comp->BodyInstance.SetObjectType(ECC_WorldDynamic);
	Comp->BodyInstance.SetCollisionEnabled(ECollisionEnabled::QueryAndPhysics);
	Comp->BodyInstance.SetResponseToAllChannels(ECR_Ignore);
	Comp->BodyInstance.SetResponseToChannel(ECC_WorldStatic, ECR_Block);
	Comp->BodyInstance.SetResponseToChannel(ECC_WorldDynamic, ECR_Block);
	Comp->BodyInstance.SetResponseToChannel(ECC_Pawn, ECR_Block);
	Comp->SetHiddenInGame(false);
}


.Cpp Constructor

    //Asset, Reference Obtained Via Right Click in Editor
static ConstructorHelpers::FObjectFinder<UStaticMesh> StaticMeshOb_AW2(TEXT("StaticMesh'/Game/VictoryGoals/Mechs/JoyControl/JoyControl_WindTurtle.JoyControl_WindTurtle'"));

AssetSM_JoyControl = StaticMeshOb_AW2.Object;

//Create
JoyfulControl = ObjectInitializer.CreateDefaultSubobject < UStaticMeshComponent > (this, TEXT("JoyfulControlYay"));

//Set Mesh
JoyfulControl->SetStaticMesh(AssetSM_JoyControl);

//Setup (see .h)
SetupSMComponentsWithCollision(JoyfulControl);

//Deferred Attachment (Ty Nick W.! Actual attach gets done after blueprint stuff)
JoyfulControl->AttachParent = Mesh;
JoyfulControl->AttachSocketName = "JoyControl";

What is Mesh?

Mesh is a great choice for a component to attach to if you are deriving from an ACharacter class.

If not using ACharacter, and if you have a RootComponent for your actor class already,

you can simply replace Mesh with RootComponent

 JoyfulControl->AttachParent = RootComponent;

If you are making a new actor class that does not have a RootComponent, then make one of your new components into the RootComponent

 RootComponent = YourComp;

Conclusion

Enjoy!

Warning!

AttachParent not available anymore. Use SetupAttachment instead.

Rama (talk)