The Hierarchy Window

The Hierarchy contains every GameObject in the current Scene. Some of these are direct instances of asset files like 3D models, and others are instances of Prefabs, custom objects that will make up much of your game. You can select objects in the Hierarchy and drag one object onto another to make use of Parenting (see below). As objects are added and removed in the scene, they will appear and disappear from the Hierarchy as well. By default the GameObjects will be listed in the Hierarchy window in the order they are made. It is possible to re-order the GameObjects by dragging them up or down, or making them children or parents.

Parenting

Unity uses a concept called Parenting. To make any GameObject the child of another, drag the desired child onto the desired parent in the Hierarchy. A child will inherit the movement and rotation of its parent. You can use a parent object’s foldout arrow to show or hide its children as necessary. Alt-clicking the parent’s foldout arrow will show or hide all descendent GameObjects of the parent, in addition to the immediate children.

To learn more about parenting, see the Transform Component page.

Alphanumeric Sorting

The order of GameObjects in the Hierarchy window can be changed into alphanumeric order. This mode can be enabled using the Edit->Preferences menu (Windows) or Unity->Preferences menu (Mac) which launches the Unity Preferences window. The “Enable Alpha Numeric Sorting” can be ticked. Once this is made the order of the GameObjects in the Hierarchy can be made into alphanumberic sorting. A new icon appears at the top right-hand side of the Hierarchy window. A drop-down appears which lets you choose Alphabetic or Transform sort.

Multi-Scene Editing

It is possible to have more than one Scene open in the Hierarchy at the same time. To find out more about this, see the Multi Scene Editing page.