The height of the node relative to its parent.
- iOS 7.0+
- macOS 10.9+
- tvOS 9.0+
- watchOS 3.0+
The default value is
0. The positive z axis is projected toward the viewer so that nodes with larger z-position values are closer to the viewer. When a node tree is rendered, the height of each node (in absolute coordinates) is calculated and then all nodes in the tree are rendered from smallest z-position value to largest z-position value. If multiple nodes share the same z-position, those nodes are sorted so that parent nodes are drawn before their children, and siblings are rendered in the order that they appear in their parent’s
children array. Hit-testing is processed in the opposite order.