Using Base Nodes to Lay Out SpriteKit Content
Use nonvisual nodes to define the layout of a scene.
Each onscreen element in SpriteKit is referred to as a node. Nodes are either visual elements or containers of other nodes. You set up the appearance of a SpriteKit scene by adding nodes alongside and on top of each other in a hierarchical form. Collectively, this structure is referred to as the node tree or the node hierarchy.
These are the basic nonvisual nodes in SpriteKit:
SKNodeis a container node. It doesn’t render any content of its own, but works as a layout tool for its child nodes.
SKReferenceNodedoesn’t define content of its own, but refers to another node or archived file that does.
SKCameraNodedefines point of view within a scene. Its inverse scale is applied to all nodes in the hierarchy except for its children. Use the children of SKCameraNode for UI elements that should be unaffected by zoom level.