Unreal Engine

Garbage Collection

• Raw pointers to UObjects get garbage collected — use UPROPERTY() to prevent
• UPROPERTY() marks for GC tracking — without it, pointer becomes dangling
• TWeakObjectPtr for optional references — doesn't prevent collection, check IsValid()
• NewObject<T>() for UObjects — never raw new, GC won't track it

UPROPERTY and UFUNCTION

• UPROPERTY() required for Blueprint access — and for GC tracking
• UFUNCTION() for Blueprint callable/events — also required for replication
• EditAnywhere vs VisibleAnywhere — edit allows changes, visible is read-only
• BlueprintReadWrite vs BlueprintReadOnly — controls Blueprint access level

Actor Lifecycle

• BeginPlay after all components initialized — safe to access components
• Constructor runs on CDO (Class Default Object) — don't spawn actors or access world
• PostInitializeComponents before BeginPlay — for component setup
• EndPlay for cleanup — called on destroy and level transition