24
AutoCAD and Its Applications—Advanced
Once you select a view, the viewpoint in the current viewport is automatically
changed to display an appropriate isometric or orthographic view. Since these presets
are based on the WCS, selecting a preset produces the same view of the object regard-
less of the current user coordinate system (UCS).
A view that looks straight down on the current drawing plane is called a plan
view. An important aspect of the orthographic presets is that selecting one not only
changes the viewpoint, but, by default, it also changes the UCS to be plan to the ortho-
graphic view. All new objects are created on that UCS instead of the WCS (or previous
UCS). Working with UCSs is explained in detail in Chapter 4. However, in order to
change the UCS to the WCS, type
UCS
to access the
UCS
command and then type
W
for the
World
option.
When an isometric or other 3D view is displayed, you can easily switch to a plan
view of the current UCS by typing the
PLAN
command and selecting the
Current
option. The
PLAN
command is discussed in more detail in Chapter 3.
NOTET T OT TE
You can also change the viewpoint to one of the orthographic or
isometric presets by using the
VIEW
command to access the
View
Manager
dialog box.
NOTTE OT
Selecting an orthographic view of a model using one of the methods
described previously produces a plan view, but it may not achieve
the results you desire. Three-dimensional models can be displayed in
AutoCAD using either parallel or perspective projection. Displaying
a plan view in either projection is possible. However, a true plan view,
as used in 2D orthographic projections, can only be created when the
model is displayed as a parallel projection. You can quickly change
the display from perspective to parallel, or vice versa, by picking
either
Parallel
or
Perspective
in the
View Controls
fl yout in the view- fl
port controls. The current projection is checked in the flyout. fl
Figure 1-12.
Selecting preset
views using the
View
panel in the
Home
tab of the ribbon.
Pick to
display the
View Manager
dialog box
Orthographic
preset views
Isometric
preset views