Code Examples

Complete implementation examples for the platformer system components.

Character Class (APlatformCharacter)

Header Declaration

cpp

#pragma once

#include "CoreMinimal.h"
#include "GameFramework/Character.h"
#include "InputActionValue.h"
#include "PlatformCharacter.generated.h"

class USpringArmComponent;
class UCameraComponent;
class UInputMappingContext;
class UInputAction;
class UCharacterTuningData;

UCLASS()
class PLATFORMER_API APlatformCharacter : public ACharacter
{
	GENERATED_BODY()

public:
	APlatformCharacter();

protected:
	virtual void BeginPlay() override;
	virtual void SetupPlayerInputComponent(class UInputComponent* PlayerInputComponent) override;

	// Input Actions
	UPROPERTY(EditAnywhere, BlueprintReadOnly, Category = Input)
	UInputMappingContext* DefaultMappingContext;

	UPROPERTY(EditAnywhere, BlueprintReadOnly, Category = Input)
	UInputAction* JumpAction;

	UPROPERTY(EditAnywhere, BlueprintReadOnly, Category = Input)
	UInputAction* MoveAction;

	UPROPERTY(EditAnywhere, BlueprintReadOnly, Category = Input)
	UInputAction* LookAction;

	UPROPERTY(EditAnywhere, BlueprintReadOnly, Category = Input)
	UInputAction* SprintAction;

	UPROPERTY(EditAnywhere, BlueprintReadOnly, Category = Input)
	UInputAction* InteractAction;

	// Tuning Data
	UPROPERTY(EditAnywhere, BlueprintReadOnly, Category = Tuning)
	UCharacterTuningData* TuningData;

	// Input Functions
	void Move(const FInputActionValue& Value);
	void Look(const FInputActionValue& Value);
	void StartSprint();
	void StopSprint();
	void Interact();

private:
	UPROPERTY(VisibleAnywhere, BlueprintReadOnly, Category = Camera, meta = (AllowPrivateAccess = "true"))
	USpringArmComponent* CameraBoom;

	UPROPERTY(VisibleAnywhere, BlueprintReadOnly, Category = Camera, meta = (AllowPrivateAccess = "true"))
	UCameraComponent* FollowCamera;

	bool bIsSprinting = false;

public:
	FORCEINLINE USpringArmComponent* GetCameraBoom() const { return CameraBoom; }
	FORCEINLINE UCameraComponent* GetFollowCamera() const { return FollowCamera; }
};

Constructor Implementation

cpp

APlatformCharacter::APlatformCharacter()
{
	// Set size for collision capsule
	GetCapsuleComponent()->InitCapsuleSize(42.f, 96.0f);

	// Configure character rotation (don't rotate with controller for platformer)
	bUseControllerRotationPitch = false;
	bUseControllerRotationYaw = false;
	bUseControllerRotationRoll = false;

	// Configure character movement
	GetCharacterMovement()->bOrientRotationToMovement = true;
	GetCharacterMovement()->RotationRate = FRotator(0.0f, 500.0f, 0.0f);
	GetCharacterMovement()->JumpZVelocity = 700.f;
	GetCharacterMovement()->AirControl = 0.35f;
	GetCharacterMovement()->MaxWalkSpeed = 600.0f;
	GetCharacterMovement()->MinAnalogWalkSpeed = 20.f;
	GetCharacterMovement()->BrakingDecelerationWalking = 2000.f;
	GetCharacterMovement()->JumpMaxCount = 2; // Double jump

	// Create camera boom
	CameraBoom = CreateDefaultSubobject<USpringArmComponent>(TEXT("CameraBoom"));
	CameraBoom->SetupAttachment(RootComponent);
	CameraBoom->TargetArmLength = 450.0f;
	CameraBoom->bUsePawnControlRotation = false;
	CameraBoom->SetRelativeRotation(FRotator(-15.0f, 0.0f, 0.0f));

	// Create follow camera
	FollowCamera = CreateDefaultSubobject<UCameraComponent>(TEXT("FollowCamera"));
	FollowCamera->SetupAttachment(CameraBoom, USpringArmComponent::SocketName);
	FollowCamera->bUsePawnControlRotation = false;
}

Interaction System

IInteractable Interface

cpp

#pragma once

#include "CoreMinimal.h"
#include "UObject/Interface.h"
#include "Interactable.generated.h"

UINTERFACE(MinimalAPI, Blueprintable)
class UInteractable : public UInterface
{
	GENERATED_BODY()
};

class PLATFORMER_API IInteractable
{
	GENERATED_BODY()

public:
	// Get the verb to display in UI (e.g., "Open", "Pickup", "Talk")
	UFUNCTION(BlueprintImplementableEvent, BlueprintCallable, Category = "Interaction")
	FText GetInteractionVerb() const;

	// Get the display name of this object
	UFUNCTION(BlueprintImplementableEvent, BlueprintCallable, Category = "Interaction")
	FText GetInteractionName() const;

	// Check if this object can be interacted with by the given instigator
	UFUNCTION(BlueprintImplementableEvent, BlueprintCallable, Category = "Interaction")
	bool CanInteract(AActor* Instigator) const;

	// Perform the interaction
	UFUNCTION(BlueprintImplementableEvent, BlueprintCallable, Category = "Interaction")
	void Interact(AActor* Instigator);
};

UInteractionComponent

cpp

#pragma once

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

class IInteractable;

UCLASS(ClassGroup=(Custom), meta=(BlueprintSpawnableComponent))
class PLATFORMER_API UInteractionComponent : public UActorComponent
{
	GENERATED_BODY()

public:
	UInteractionComponent();

protected:
	virtual void BeginPlay() override;
	virtual void TickComponent(float DeltaTime, ELevelTick TickType, FActorComponentTickFunction* ThisTickFunction) override;

	UPROPERTY(EditAnywhere, BlueprintReadOnly, Category = "Interaction")
	float InteractionRange = 250.0f;

	UPROPERTY(EditAnywhere, BlueprintReadOnly, Category = "Interaction")
	float InteractionRadius = 60.0f;

	UPROPERTY(BlueprintReadOnly, Category = "Interaction")
	AActor* CurrentFocusActor = nullptr;

public:
	UFUNCTION(BlueprintCallable, Category = "Interaction")
	void TryInteract();

	UFUNCTION(BlueprintCallable, Category = "Interaction")
	AActor* GetCurrentFocusActor() const { return CurrentFocusActor; }

private:
	void UpdateFocusActor();
	AActor* FindBestInteractable();
};

Interaction Component Implementation

cpp

#include "InteractionComponent.h"
#include "Engine/World.h"
#include "GameFramework/PlayerController.h"
#include "Camera/CameraComponent.h"
#include "Interactable.h"

UInteractionComponent::UInteractionComponent()
{
	PrimaryComponentTick.bCanEverTick = true;
	PrimaryComponentTick.TickInterval = 0.1f; // Check 10 times per second
}

void UInteractionComponent::BeginPlay()
{
	Super::BeginPlay();
}

void UInteractionComponent::TickComponent(float DeltaTime, ELevelTick TickType, FActorComponentTickFunction* ThisTickFunction)
{
	Super::TickComponent(DeltaTime, TickType, ThisTickFunction);
	UpdateFocusActor();
}

void UInteractionComponent::UpdateFocusActor()
{
	AActor* NewFocusActor = FindBestInteractable();

	if (NewFocusActor != CurrentFocusActor)
	{
		CurrentFocusActor = NewFocusActor;
		// Trigger UI update event here
	}
}

AActor* UInteractionComponent::FindBestInteractable()
{
	APawn* OwnerPawn = Cast<APawn>(GetOwner());
	if (!OwnerPawn)
		return nullptr;

	APlayerController* PC = Cast<APlayerController>(OwnerPawn->GetController());
	if (!PC)
		return nullptr;

	// Get camera location and forward direction
	FVector CameraLocation = PC->PlayerCameraManager->GetCameraLocation();
	FVector ForwardDirection = PC->PlayerCameraManager->GetCameraRotation().Vector();

	// Sphere trace for interactables
	FCollisionQueryParams QueryParams;
	QueryParams.AddIgnoredActor(OwnerPawn);

	TArray<FHitResult> HitResults;
	FVector TraceEnd = CameraLocation + (ForwardDirection * InteractionRange);

	bool bHit = GetWorld()->SweepMultiByChannel(
		HitResults,
		CameraLocation,
		TraceEnd,
		FQuat::Identity,
		ECC_Visibility,
		FCollisionShape::MakeSphere(InteractionRadius),
		QueryParams
	);

	if (!bHit)
		return nullptr;

	// Find best interactable (closest to camera center)
	AActor* BestActor = nullptr;
	float BestDot = -1.0f;

	for (const FHitResult& Hit : HitResults)
	{
		if (Hit.GetActor() && Hit.GetActor()->Implements<UInteractable>())
		{
			// Check if we can interact
			if (IInteractable::Execute_CanInteract(Hit.GetActor(), OwnerPawn))
			{
				// Calculate how "centered" this actor is in our view
				FVector ToActor = (Hit.GetActor()->GetActorLocation() - CameraLocation).GetSafeNormal();
				float DotProduct = FVector::DotProduct(ForwardDirection, ToActor);

				if (DotProduct > BestDot)
				{
					BestDot = DotProduct;
					BestActor = Hit.GetActor();
				}
			}
		}
	}

	return BestActor;
}

void UInteractionComponent::TryInteract()
{
	if (CurrentFocusActor && CurrentFocusActor->Implements<UInteractable>())
	{
		IInteractable::Execute_Interact(CurrentFocusActor, GetOwner());
	}
}

Stats Component

UStatsComponent Header

cpp

#pragma once

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

DECLARE_DYNAMIC_MULTICAST_DELEGATE_ThreeParams(FOnHealthChanged, float, CurrentHealth, float, MaxHealth, float, HealthPercentage);
DECLARE_DYNAMIC_MULTICAST_DELEGATE_TwoParams(FOnDeath, AActor*, Killer, AActor*, Victim);

UCLASS(ClassGroup=(Custom), meta=(BlueprintSpawnableComponent))
class PLATFORMER_API UStatsComponent : public UActorComponent
{
	GENERATED_BODY()

public:
	UStatsComponent();

protected:
	virtual void BeginPlay() override;

	UPROPERTY(EditAnywhere, BlueprintReadOnly, Category = "Stats")
	float MaxHealth = 100.0f;

	UPROPERTY(EditAnywhere, BlueprintReadOnly, Category = "Stats")
	float MaxStamina = 100.0f;

	UPROPERTY(EditAnywhere, BlueprintReadOnly, Category = "Stats")
	float HealthRegenRate = 0.0f; // Per second

	UPROPERTY(EditAnywhere, BlueprintReadOnly, Category = "Stats")
	float HealthRegenDelay = 3.0f; // Seconds after taking damage

	UPROPERTY(BlueprintReadOnly, Category = "Stats")
	float CurrentHealth;

	UPROPERTY(BlueprintReadOnly, Category = "Stats")
	float CurrentStamina;

private:
	FTimerHandle HealthRegenTimerHandle;
	float LastDamageTime = 0.0f;

public:
	UPROPERTY(BlueprintAssignable, Category = "Events")
	FOnHealthChanged OnHealthChanged;

	UPROPERTY(BlueprintAssignable, Category = "Events")
	FOnDeath OnDeath;

	UFUNCTION(BlueprintCallable, Category = "Stats")
	float ApplyDamage(float DamageAmount, AActor* DamageCauser = nullptr);

	UFUNCTION(BlueprintCallable, Category = "Stats")
	void RestoreHealth(float HealAmount);

	UFUNCTION(BlueprintCallable, Category = "Stats")
	bool IsAlive() const { return CurrentHealth > 0.0f; }

	UFUNCTION(BlueprintCallable, Category = "Stats")
	float GetHealthPercentage() const { return MaxHealth > 0 ? CurrentHealth / MaxHealth : 0.0f; }

private:
	void StartHealthRegen();
	void TickHealthRegen();
};

Data Assets

Character Tuning Data

cpp

#pragma once

#include "CoreMinimal.h"
#include "Engine/DataAsset.h"
#include "CharacterTuningData.generated.h"

UCLASS(BlueprintType)
class PLATFORMER_API UCharacterTuningData : public UPrimaryDataAsset
{
	GENERATED_BODY()

public:
	// Movement settings
	UPROPERTY(EditAnywhere, BlueprintReadOnly, Category = "Movement", meta = (ClampMin = "100", ClampMax = "1000"))
	float WalkSpeed = 600.0f;

	UPROPERTY(EditAnywhere, BlueprintReadOnly, Category = "Movement", meta = (ClampMin = "200", ClampMax = "1500"))
	float SprintSpeed = 900.0f;

	UPROPERTY(EditAnywhere, BlueprintReadOnly, Category = "Movement", meta = (ClampMin = "300", ClampMax = "1200"))
	float JumpZVelocity = 700.0f;

	UPROPERTY(EditAnywhere, BlueprintReadOnly, Category = "Movement", meta = (ClampMin = "0.1", ClampMax = "1.0"))
	float AirControl = 0.35f;

	UPROPERTY(EditAnywhere, BlueprintReadOnly, Category = "Movement", meta = (ClampMin = "1", ClampMax = "3"))
	int32 JumpMaxCount = 2;

	// Camera settings
	UPROPERTY(EditAnywhere, BlueprintReadOnly, Category = "Camera", meta = (ClampMin = "200", ClampMax = "800"))
	float CameraDistance = 450.0f;

	UPROPERTY(EditAnywhere, BlueprintReadOnly, Category = "Camera", meta = (ClampMin = "1", ClampMax = "25"))
	float CameraLagSpeed = 12.0f;

	UPROPERTY(EditAnywhere, BlueprintReadOnly, Category = "Camera", meta = (ClampMin = "1", ClampMax = "25"))
	float CameraRotationLagSpeed = 10.0f;

	UPROPERTY(EditAnywhere, BlueprintReadOnly, Category = "Camera", meta = (ClampMin = "-45", ClampMax = "45"))
	float CameraAngle = -15.0f;
};

Enhanced Input Setup

Input Action Creation (Blueprint)

cpp

// This would be created in Blueprint, but here's how to reference them in C++

// In your character's header:
UPROPERTY(EditAnywhere, BlueprintReadOnly, Category = Input)
UInputAction* MoveAction;

UPROPERTY(EditAnywhere, BlueprintReadOnly, Category = Input)
UInputAction* LookAction;

UPROPERTY(EditAnywhere, BlueprintReadOnly, Category = Input)
UInputAction* JumpAction;

UPROPERTY(EditAnywhere, BlueprintReadOnly, Category = Input)
UInputAction* SprintAction;

UPROPERTY(EditAnywhere, BlueprintReadOnly, Category = Input)
UInputAction* InteractAction;

// In SetupPlayerInputComponent:
if (UEnhancedInputComponent* EnhancedInputComponent = CastChecked<UEnhancedInputComponent>(PlayerInputComponent))
{
	EnhancedInputComponent->BindAction(JumpAction, ETriggerEvent::Triggered, this, &ACharacter::Jump);
	EnhancedInputComponent->BindAction(JumpAction, ETriggerEvent::Completed, this, &ACharacter::StopJumping);

	EnhancedInputComponent->BindAction(MoveAction, ETriggerEvent::Triggered, this, &APlatformCharacter::Move);
	EnhancedInputComponent->BindAction(LookAction, ETriggerEvent::Triggered, this, &APlatformCharacter::Look);

	EnhancedInputComponent->BindAction(SprintAction, ETriggerEvent::Started, this, &APlatformCharacter::StartSprint);
	EnhancedInputComponent->BindAction(SprintAction, ETriggerEvent::Completed, this, &APlatformCharacter::StopSprint);

	EnhancedInputComponent->BindAction(InteractAction, ETriggerEvent::Triggered, this, &APlatformCharacter::Interact);
}

Common Patterns

Safe Casting Pattern

cpp

// Always use safe casting for UObjects
if (APawn* OwnerPawn = Cast<APawn>(GetOwner()))
{
	if (APlayerController* PC = Cast<APlayerController>(OwnerPawn->GetController()))
	{
		// Safe to use PC here
	}
}

Component Access Pattern

cpp

// Safe component access
if (UStatsComponent* StatsComp = GetOwner()->FindComponentByClass<UStatsComponent>())
{
	StatsComp->ApplyDamage(DamageAmount);
}

Interface Implementation Check

cpp

// Check if actor implements interface
if (TargetActor && TargetActor->Implements<UInteractable>())
{
	// Safe to call interface functions
	IInteractable::Execute_Interact(TargetActor, this);
}

Timer Usage Pattern

cpp

// Setting up a timer
FTimerHandle TimerHandle;
GetWorld()->GetTimerManager().SetTimer(
	TimerHandle,
	this,
	&UMyComponent::MyTimerFunction,
	1.0f,  // Delay
	true   // Looping
);

// Clearing a timer
GetWorld()->GetTimerManager().ClearTimer(TimerHandle);

These examples provide the foundation for implementing all the milestone features. Each example includes proper UE5 patterns, memory safety, and Blueprint integration points.

This page provides minimal C++ code snippets for key concepts.

Enhanced Input Setup

Input Action Asset setup (in editor):

Create Input Action IA_Move (Value Type: Axis2D)
Create Input Action IA_Jump (Value Type: Digital Bool)
Create Input Mapping Context IMC_Player

Character header snippet:

cpp

UCLASS()
class PLATFORMER_API APlatformCharacter : public ACharacter
{
    GENERATED_BODY()

public:
    APlatformCharacter();

protected:
    UPROPERTY(VisibleAnywhere, BlueprintReadOnly, Category = Camera)
    class USpringArmComponent* CameraBoom;

    UPROPERTY(VisibleAnywhere, BlueprintReadOnly, Category = Camera)
    class UCameraComponent* FollowCamera;

    UPROPERTY(EditDefaultsOnly, Category = Input)
    class UInputMappingContext* DefaultMappingContext;

    UPROPERTY(EditDefaultsOnly, Category = Input)
    class UInputAction* MoveAction;

    UPROPERTY(EditDefaultsOnly, Category = Input)
    class UInputAction* JumpAction;

protected:
    virtual void BeginPlay() override;
    virtual void SetupPlayerInputComponent(UInputComponent* PlayerInputComponent) override;

    void Move(const FInputActionValue& Value);
    void StartJump();
    void StopJump();
};

Interface Example

IInteractable interface:

cpp

UINTERFACE(MinimalAPI, BlueprintType)
class UInteractable : public UInterface
{
    GENERATED_BODY()
};

class PLATFORMER_API IInteractable
{
    GENERATED_BODY()

public:
    virtual FText GetInteractionVerb() const = 0;
    virtual bool CanInteract(AActor* Instigator) const = 0;
    virtual void Interact(AActor* Instigator) = 0;
};

Data Asset Example

Character tuning data asset:

cpp

UCLASS()
class PLATFORMER_API UCharacterTuningData : public UPrimaryDataAsset
{
    GENERATED_BODY()

public:
    UPROPERTY(EditDefaultsOnly, Category = "Movement")
    float WalkSpeed = 600.0f;

    UPROPERTY(EditDefaultsOnly, Category = "Movement")
    float SprintSpeed = 900.0f;

    UPROPERTY(EditDefaultsOnly, Category = "Movement")
    float AirControl = 0.5f;

    UPROPERTY(EditDefaultsOnly, Category = "Movement")
    int32 JumpMaxCount = 2;

    virtual FPrimaryAssetId GetPrimaryAssetId() const override;
};

Component Example

Stats component header:

cpp

UCLASS(ClassGroup=(Custom), meta=(BlueprintSpawnableComponent))
class PLATFORMER_API UStatsComponent : public UActorComponent
{
    GENERATED_BODY()

public:
    UStatsComponent();

    DECLARE_DYNAMIC_MULTICAST_DELEGATE_TwoParams(FOnDeath, AActor*, Victim, AActor*, Killer);

    UPROPERTY(BlueprintAssignable)
    FOnDeath OnDeath;

protected:
    UPROPERTY(EditDefaultsOnly, Category = "Stats")
    float HealthMax = 100.0f;

    UPROPERTY(BlueprintReadOnly, Category = "Stats")
    float Health = 100.0f;

public:
    UFUNCTION(BlueprintCallable, Category = "Stats")
    float ApplyDamage(float DamageAmount, AActor* DamageCauser);

    UFUNCTION(BlueprintPure, Category = "Stats")
    float GetHealthPercent() const { return Health / HealthMax; }
};

Code Examples ​

Character Class (APlatformCharacter) ​

Header Declaration ​

Constructor Implementation ​

Interaction System ​

IInteractable Interface ​

UInteractionComponent ​

Interaction Component Implementation ​

Stats Component ​

UStatsComponent Header ​

Data Assets ​

Character Tuning Data ​

Enhanced Input Setup ​

Input Action Creation (Blueprint) ​

Common Patterns ​

Safe Casting Pattern ​

Component Access Pattern ​

Interface Implementation Check ​

Timer Usage Pattern ​

Enhanced Input Setup ​

Interface Example ​

Data Asset Example ​

Component Example ​

Code Examples

Character Class (APlatformCharacter)

Header Declaration

Constructor Implementation

Interaction System

IInteractable Interface

UInteractionComponent

Interaction Component Implementation

Stats Component

UStatsComponent Header

Data Assets

Character Tuning Data

Enhanced Input Setup

Input Action Creation (Blueprint)

Common Patterns

Safe Casting Pattern

Component Access Pattern

Interface Implementation Check

Timer Usage Pattern

Enhanced Input Setup

Interface Example

Data Asset Example

Component Example