The VisibleOnScreenEnabler3D will disable [RigidDynamicBody3D] and [AnimationPlayer] nodes when they are not visible. It will only affect other nodes within the same scene as the VisibleOnScreenEnabler3D itself.
If you just want to receive notifications, use [VisibleOnScreenNotifier3D] instead.
[b]Note:[/b] VisibleOnScreenEnabler3D uses an approximate heuristic for performance reasons. It doesn't take walls and other occlusion into account. The heuristic is an implementation detail and may change in future versions. If you need precise visibility checking, use another method such as adding an [Area3D] node as a child of a [Camera3D] node and/or [method Vector3.dot].
[b]Note:[/b] VisibleOnScreenEnabler3D will not affect nodes added after scene initialization.