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