Detect when the node is visible on screen. The VisibilityNotifier2D is used to notify when its bounding rectangle enters the screen, is visible on the screen, or when it exits the screen. Return the visibility bounding rectangle of the VisibilityNotifier2D. Return true if any part of the bounding rectangle is on the screen. Set the visibility bounding rectangle of the VisibilityNotifier2D. Emitted when the VisibilityNotifier2D enters the screen. Emitted when the VisibilityNotifier2D exits the screen. Emitted when the VisibilityNotifier2D enters a [Viewport]'s view. Emitted when the VisibilityNotifier2D exits a [Viewport]'s view.