The
view panel appears when you enter camera move mode (by holding
+
) in the Perspective window.
This window lets you quickly switch the Perspective window to common
default or user-defined views of the model.
Hold
+
to show the view panel,
then click any of the controls in the view panel:

Of special interest are the following tools:
Clicking on the Look at icon centers the view and zooms in on the selected objects (or all objects if nothing is picked). See also Center the view on specific objects.
Checking Plane view lets you tumble about the currently active construction plane (i.e. the construction plane will be used as the ground plane).
As you work on the model, you will probably find yourself changing the camera view back and forth between two or more areas of interest. The view panel lets you “bookmark” views of the model and return to those views by clicking the name of the bookmark.
Additionally, shading attributes (from the Diagnostic
Shading panel or WindowDisplay > Hardware Shade
), and annotations (created
using tools in the Paint tab) are stored in bookmarks.
When switching from one bookmark (or view) to the next, the camera is animated to take you smoothly from one view to another without getting disoriented.
The time (in seconds) taken to transition from
one view to the next is controlled by the View transition time option
in Preferences > General Preferences
(Model Windows section).

The default is 0.5 seconds. When this value is set to 0.0, the smooth animation is turned off.
Bookmark an annotated modelor more details on annotating bookmarks.
Add bookmark for the current view
+
.
+
.
This opens the Bookmark Lister.

+
and do any
of the following in the Bookmark Lister:
and double-click the bookmark
icon. Type a new name in the dialog box, then click OK.
You can also use the Page Up and Page Down keys as a quick way to show the previous or next bookmark without the need to open the Bookmark Lister.
Save one or all bookmarks as image files
A green border appears around the selected (current) bookmark.
A file browser window is displayed.

.
The saved images are called <object name>_<bookmark name>.<file type>.
The view panel does not appear when I hold
+
?