Widget data binding: update UI automatically when variable changes

METHOD 1 - Function Binding (auto-updates every frame, easy but has perf cost): In Widget BP: select TextBlock → Details → Content → Text → click 'Bind' → Create Binding → connect your data (e.g. GetPlayerHealth as Text). METHOD 2 - Event-driven (recommended, update only when needed): In owning actor: when data changes → CastTo<WBP_HUD>(HUDWidget) → call custom function 'UpdateHealth(NewHealth)' on widget. In Widget BP: UpdateHealth function → SetText(HealthText, Conv_FloatToString(NewHealth)). KEY: Function bindings run every frame. For frequently-changing data (Tick-speed), use Event-driven approach instead to avoid perf issues.

AddImpulse — apply an instant velocity change to a physics body

bVelChange=true treats Impulse as direct velocity change (ignores mass). bVelChange=false treats it as a force impulse (mass-dependent).

SetMaterial — change material on mesh component at index

SetSkeletalMesh — change skeletal mesh on mesh component

UE5 uses SetSkeletalMeshAsset, not SetSkeletalMesh.

SetStaticMesh — change static mesh on mesh component

SetColorAndOpacity — change widget color and transparency

SetScalarParameterValue on dynamic material — change float material parameter

UMaterialInstanceDynamic method. Parameter name must match material graph.

Level transition: save data then open new level

Pattern: custom trigger or UI button → [save player data to SaveSlot] → OpenLevel(LevelName='Level_02', bAbsolute=true, Options=''). For loading screen: SetGlobalTimeDilation(0.001) briefly while level loads (freeze world), or use AsyncLoadLevel with progress callback. Key: OpenLevel is in GameplayStatics. 'LevelName' is the map asset name (not full path). bAbsolute=true discards current level completely. Options string can pass params like '?GameMode=BP_GM'.

Replace string — replace occurrences in string

Power — raise base to exponent power

Internal function name is MultiplyMultiply_FloatFloat (operator **).