unreal-engine-cpp-pro

name unreal-engine-cpp-pro description Expert guide for Unreal Engine 5.x C++ development, covering UObject hygiene, performance patterns, and best practices. risk safe source self date_added 2026-02-27 Unreal Engine C++ Pro This skill provides expert-level guidelines for developing with Unreal Engine 5 using C++. It focuses on writing robust, performant, and standard-compliant code. When to Use Use this skill when: Developing C++ code for Unreal Engine 5.x projects Writing Actors, Components, or UObject-derived classes Optimizing performance-critical code in Unreal Engine Debugging memory leaks or garbage collection issues Implementing Blueprint-exposed functionality Following Epic Games' coding standards and conventions Working with Unreal's reflection system (UCLASS, USTRUCT, UFUNCTION) Managing asset loading and soft references Do not use this skill when: Working with Blueprint-only projects (no C++ code) Developing for Unreal Engine versions prior to 5.x Working on non-Unreal game engines The task is unrelated to Unreal Engine development Core Principles UObject & Garbage Collection : Always use UPROPERTY() for UObject* member variables to ensure they are tracked by the Garbage Collector (GC). Use TStrongObjectPtr<> if you need to keep a root reference outside of a UObject graph, but prefer addToRoot() generally. Understand the IsValid() check vs nullptr . IsValid() handles pending kill state safely. Unreal Reflection System : Use UCLASS() , USTRUCT() , UENUM() , UFUNCTION() to expose types to the reflection system and Blueprints. Minimize BlueprintReadWrite when possible; prefer BlueprintReadOnly for state that shouldn't be trampled by logic in UI/Level BPs. Performance First : Tick : Disable Ticking ( bCanEverTick = false ) by default. Only enable it if absolutely necessary. Prefer timers ( GetWorldTimerManager() ) or event-driven logic. Casting : Avoid Cast<T>() in hot loops. Cache references in BeginPlay . Structs vs Classes : Use F structs for data-heavy, non-UObject types to reduce overhead. Naming Conventions (Strict) Follow Epic Games' coding standard: Templates : Prefix with T (e.g., TArray , TMap ). UObject : Prefix with U (e.g., UCharacterMovementComponent ). AActor : Prefix with A (e.g., AMyGameMode ). SWidget : Prefix with S (Slate widgets). Structs : Prefix with F (e.g., FVector ). Enums : Prefix with E (e.g., EWeaponState ). Interfaces : Prefix with I (e.g., IInteractable ). Booleans : Prefix with b (e.g., bIsDead ). Common Patterns 1. Robust Component Lookup Avoid GetComponentByClass in Tick . Do it in PostInitializeComponents or BeginPlay . void AMyCharacter::PostInitializeComponents () { Super:: PostInitializeComponents (); HealthComp = FindComponentByClass <UHealthComponent>(); check (HealthComp); // Fail hard in dev if missing } 2. Interface Implementation Use interfaces to decouple systems (e.g., Interaction system). // Interface call check if (TargetActor-> Implements <UInteractable>()) { IInteractable:: Execute_OnInteract (TargetActor, this ); } 3. Async Loading (Soft References) Avoid hard references ( UPROPERTY(EditDefaultsOnly) TSubclassOf<AActor> ) for massive assets which force load orders. Use TSoftClassPtr or TSoftObjectPtr . UPROPERTY (EditAnywhere, BlueprintReadWrite) TSoftClassPtr<AWeapon> WeaponClassToLoad; void AMyCharacter::Equip () { if (WeaponClassToLoad. IsPending ()) { WeaponClassToLoad. LoadSynchronous (); // Or use StreamableManager for async } } Debugging Logging : Use UE_LOG with custom categories. DEFINE_LOG_CATEGORY_STATIC (LogMyGame, Log, All); UE_LOG (LogMyGame, Warning, TEXT ( "Health is low: %f" ), CurrentHealth); Screen Messages : if (GEngine) GEngine-> AddOnScreenDebugMessage ( -1 , 5.f , FColor::Red, TEXT ( "Died!" )); Visual Logger : extremely useful for AI debugging. Implement IVisualLoggerDebugSnapshotInterface . Checklist before PR Does this Actor need to Tick? Can it be a Timer? Are all UObject* members wrapped in UPROPERTY ? Are hard references (TSubclassOf) causing load chains? Can they be Soft Ptrs? Did you clean up verified delegates in EndPlay ? Limitations Use this skill only when the task clearly matches the scope described above. Do not treat the output as a substitute for environment-specific validation, testing, or expert review. Stop and ask for clarification if required inputs, permissions, safety boundaries, or success criteria are missing.