[DevNote] Mouse Select & Hover

마우스로 인게임 오브젝트를 Hover하거나 Select 해야하는 상황

• 보통은 이 경우에 Screen 좌표상에서 InGame World로 Deprojection을 통해 Ray를 쏴서, 해당 Ray에 Hit되는 첫번째 Object를 반환하는 것 같다
• Select야 Mouse 클릭할 때만 하면 된다지만, 이 방식대로라면 Hover는 매번 Ray를 쏴야한다

PrimitiveComponent 탑재 기능

UCLASS(abstract, HideCategories=(Mobility, VirtualTexture), ShowCategories=(PhysicsVolume), MinimalAPI)
class UPrimitiveComponent : public USceneComponent, public INavRelevantInterface, public IInterface_AsyncCompilation, public IPhysicsComponent
{
  GENERATED_BODY()

  // ...

  /** Event called when the mouse cursor is moved over this component and mouse over events are enabled in the player controller */
  UPROPERTY(BlueprintAssignable, Category="Input|Mouse Input")
  FComponentBeginCursorOverSignature OnBeginCursorOver;
     
  /** Event called when the mouse cursor is moved off this component and mouse over events are enabled in the player controller */
  UPROPERTY(BlueprintAssignable, Category="Input|Mouse Input")
  FComponentEndCursorOverSignature OnEndCursorOver;

  /** Event called when the left mouse button is clicked while the mouse is over this component and click events are enabled in the player controller */
  UPROPERTY(BlueprintAssignable, Category="Input|Mouse Input")
  FComponentOnClickedSignature OnClicked;

  /** Event called when the left mouse button is released while the mouse is over this component click events are enabled in the player controller */
  UPROPERTY(BlueprintAssignable, Category="Input|Mouse Input")
  FComponentOnReleasedSignature OnReleased;

  // ...
}

• PrimitiveComponent에는 마우스 감지에 대한 이벤트를 이미 처리하고 있다
  • Generates Overlap Event 활성화 필수 및 Visibility Channel로 감지했던 걸로 기억한다
• InGame Object를 마우스로 상호작용 처리해야하는 상황이 있다면 이를 사용하는 방법도 고려할만하다