[UFUNCTION](Programming/UnrealArchitecture/Reference/Functions)(BlueprintNativeEvent, Category="ClickDrag Events") void OnDragBegin ( [FInputDeviceRay](API\Runtime\InteractiveToolsFramework\FInputDeviceRay) StartPosition, const [FScriptableToolModifierStates](API\Plugins\ScriptableToolsFramework\FScriptableToolModifierStates) & Modifiers )