Unity Engine Basics - Game Character Creation with Blender and Unity - page 235

Figure 9.20
An Empty added
to the whiteblock
level and positioned
above the level
geometry. Its name
in the Hierarchy
view is GameObject.
3. In the Hierarchy view, rename the Empty from GameObject to LevelContainer by
either clicking the object name or by RMB-clicking the object and selecting Rename
from the context menu. This will be where you place all your level geometry.
4. Select the bottom cube on the Hierarchy list by LMB-clicking. Scroll up and press
Shift+LMB to select the topmost cube on the list; this will select these two cubes and
all cubes in between.
5. LMB-click and drag these cubes onto the LevelContainer object so there is a blue
field around the word LevelContainer. Release the LMB and the cubes will disappear
from the list.
There should now be an arrow next to LevelContainer that when clicked will
show you all of the cubes in the scene. The cubes are now child objects of the
LevelContainer Empty and can therefore be hidden on the Hierarchy list.
6. Create another Empty named LightContainer and make all the point lights in the
scene child objects of the new Empty.
7. Save your scene.
While this seems like an extraneous technique, it can come in handy in situations
where you are placing lots of prefabs such as enemies, power-ups, environmental objects,
or even other Empties.