Datasheet

22n Chapter 1: Blender Basics: Interface and Objects
Managing Datablocks
Datablocks describe most aspects of modeling and animation in Blender. Materials, tex-
tures, Ipo curves, and actions are all examples of datablocks that can be freely associated
with any number of different objects after they’re created (see Figure 1.17).
In the preceding example, the Cube mesh datablock is no longer associated with any
object. Blender discards unused datablocks when it shuts down, so if you save the file and
then shut down and restart Blender with things in that state, this mesh is gone. In fact,
there is no way to actively delete such datablocks; they remain “alive” until Blender quits.
If you want to purge unused datablocks without completely quitting Blender, you can
save and then reopen your file.
Sometimes, you want to keep a datablock on hand even though it does not have a user
object. If you want an unused datablock to persist after saving, you must create a fake
user for it. For datablocks that can be retained in this way, including the ones mentioned
previously, there is be a button next to the datablock drop-down menu with the letter F,
as shown in Figure 1.17. Selecting the datablock you want to make persistent and clicking
F creates a fake user for the datablock so that it will not be discarded at shutdown.
Outliner Window
In some cases, such as actions, Blender creates a fake user automatically when the data-
block is created. In this case, you may want to remove a fake user to delete the undesired
datablock. To do this, you use the Outliner window in Datablocks view. Datablocks are
organized by type. You can navigate to the datablock you want to toggle and choose
whether it should have a fake user using the appropriate check box. Figure 1.18 shows the
check box for the Cube mesh in the Datablocks view of the Outliner. In many cases, an F
icon is shown beside mentions of a datablock. In these cases, you can remove fake users
by clicking the F icon.
The Outliner window also provides several other organized views of the data in your
.blend file. By default, it opens with the All Scenes view selected, as shown in Figure 1.19,
but you can select from different types of information to
view using the drop-down menu.
To the right of each 3D object in the scene view are
three icons: an eye, an arrow, and a camera. The eye icon
toggles visibility of the object in the 3D viewport. The
arrow icon toggles selectability in the 3D viewport. The
camera icon toggles whether the object will be rendered.
Figure 1.17
(a) The default Cube
mesh has one user,
the Cube object. If it
is unlinked from this
object, it is not per-
sisted after the file
is closed because it
has no users. (b) By
toggling the F but-
ton, a fake user is
added (the 2 refers
to the number of
users for that data-
block). Now, even
if there are no real
users of the data-
block, it persists
because its user
count is not zero.
ab
Figure 1.18
Datablocks view
in the Outliner
window
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