Nested inheritance, correct way to create child components?

[anonymous_user_bc4cfa50]

Hi all,
I’ve a problem with nested inheritance of the same class with child components.

Here is my classes hierarchy:

• ConstrainedComponent class inherits from UStaticMeshComponent class.
• Lever Class inherits from ConstrainedComponent class.
• FrontPanel Class inherits from ConstrainedComponent class, and contains a Lever Property.

The problem is that when instancing a Front Panel in game, after the BeginPlay (not before) the FrontPanel’s Constraint is moved in a wrong position (seems to accumulate parent’s positions and rotation set in the constructor).

The problem is related only when nested in this case, and can be solved by giving a different name to the Constraint Component using a progressive static int in the ConstrainedComponent Constructor. the solution is shown at the end of this post.

Here is a sample code:

 ======== ConstrainedComponent.h ===========
        UCLASS( ClassGroup=(Custom), meta=(BlueprintSpawnableComponent) )
        class ENELTRAINING_API UConstrainedComponent : public UStaticMeshComponent, public IGrabbableComponent
        {
        	GENERATED_BODY()
        public:	
                UConstrainedComponent();
        ...
        	UPROPERTY(BlueprintReadWrite, EditAnywhere, Category = "ConstrainedComponent")
        		UPhysicsConstraintComponent* Constraint;
        ...}
        ======== ConstrainedComponent.cpp ===========
        UConstrainedComponent::UConstrainedComponent() : Super()
        {
        	...
        	Constraint = CreateDefaultSubobject<UPhysicsConstraintComponent>(TEXT("Constraint"));
                Constraint->AttachParent = this;
               ...
        }
        
        
        ======== RU_Lever.h ===========
        UCLASS(ClassGroup = (Custom), meta = (BlueprintSpawnableComponent))
        class ENELTRAINING_API URU_Lever : public UConstrainedComponent
        {
        ....
        }
        
        ======== RU_FrontPanel.h ===========
        UCLASS(ClassGroup = (Custom), meta = (BlueprintSpawnableComponent))
        class ENELTRAINING_API URU_FrontPanel : public UConstrainedComponent
        {
        ...
        	UPROPERTY(BlueprintReadWrite, EditAnywhere, Category = "FrontPanel")
        		URU_Lever* Lever;	
        ...
        }

Proposed Solution in ConstrainedComponent.h constructor:

struct FConstructorStatics
	{
		int InstanceCount;
		FConstructorStatics(): InstanceCount(0)	{}
	};
	static FConstructorStatics ConstructorStatics;
	++ConstructorStatics.InstanceCount;
...
	FString ConstraintName = FString::Printf(TEXT("Constraint%i"), ConstructorStatics.InstanceCount);
	Constraint = CreateDefaultSubobject<UPhysicsConstraintComponent>(*ConstraintName);
...

Is correct to use the CreateDefaultSubobject call in the constructor instead of the NewObject?
Is the proposed solution correct or is there a more elegant way to make it work?

Thanks