BuildingEscape - Lerping a sliding door (works with any position or rotation)

[100PixelsSquared]

I did my door code the way I’d do it in Unity using the forward vector and a scalar for relative movement so it may not use UE4’s best practices.
I also found UE4’s equivalent of [System.Serialisable] to expose some variables in the editor so I don’t have to recompile when I want to change something like the lerp speed.

Here’s my code:

Header file:

#pragma once

#include "CoreMinimal.h"
#include "Components/ActorComponent.h"
#include "OpenDoor.generated.h"


UCLASS( ClassGroup=(Custom), meta=(BlueprintSpawnableComponent) )
class BUILDINGESCAPE_API UOpenDoor : public UActorComponent
{
	GENERATED_BODY()

public:	
	// Sets default values for this component's properties
	UOpenDoor();

protected:
	// Called when the game starts
	virtual void BeginPlay() override;

public:	
	// Called every frame
	virtual void TickComponent(float DeltaTime, ELevelTick TickType, FActorComponentTickFunction* ThisTickFunction) override;

public:
	FVector GetOpenPosition(const float Scalar, const bool bInvert = false) const;

private:
	UPROPERTY(EditAnywhere) AActor* DoorLeft;
	UPROPERTY(EditAnywhere) AActor* DoorRight;
	UPROPERTY(EditAnywhere) float ScalarOffset;
	UPROPERTY(EditAnywhere) float LerpSpeed;

	FVector DoorPos, ForwardVector;
	float OffsetLastFrame;
};

---

C++ script:

#include "OpenDoor.h"

// Sets default values for this component's properties
UOpenDoor::UOpenDoor()
{
	PrimaryComponentTick.bCanEverTick = true;
}

// Called when the game starts
void UOpenDoor::BeginPlay()
{
	Super::BeginPlay();

	DoorPos = GetOwner()->GetTransform().GetLocation();
	ForwardVector = GetOwner()->GetActorForwardVector();
}

// Called every frame
void UOpenDoor::TickComponent(float DeltaTime, ELevelTick TickType, FActorComponentTickFunction* ThisTickFunction)
{
	Super::TickComponent(DeltaTime, TickType, ThisTickFunction);

	float OffsetLerped = FMath::FInterpTo(OffsetLastFrame, ScalarOffset, DeltaTime, LerpSpeed);

	DoorLeft->SetActorLocation(GetOpenPosition(OffsetLerped, true));
	DoorRight->SetActorLocation(GetOpenPosition(OffsetLerped));

	OffsetLastFrame = OffsetLerped;
}

FVector UOpenDoor::GetOpenPosition(const float Scalar, const bool bInvert) const
{
	FVector VectorOffset = ForwardVector * Scalar;

	if (bInvert)
	{
		return DoorPos - VectorOffset;
	}

	return DoorPos + VectorOffset;
}

Edit:
Changed to FPS independent FInterpTo

Edit 2:
I coded it so that the entire door could be moved/rotated at runtime, but this wouldn’t work anyway due to lerping the doors. Moved setting the forward vector and door position to the start function.