2004

Table Of Contents
724 | Chapter 25 Work with Data in Other Formats
Edit Nonrectangular Layout Viewports
In AutoCAD, you can create a layout viewport with irregular boundaries by
converting an object drawn in paper space into a viewport. When you open
a drawing that contains these nonrectangular viewports in AutoCAD LT, you
can edit the viewports. For example, you can move, copy, or rotate a nonrect-
angular viewport. You can also dimension, pan, or scale the model shown in
a viewport. However, you cannot create nonrectangular viewports in
AutoCAD LT.
Work with Multiple User Coordinate Systems
In AutoCAD, you can choose to use a different user coordinate system (UCS)
in each viewport in a single drawing file. In AutoCAD LT, you can use only
one UCS in each drawing file. The AutoCAD LT behavior is the same as it was
in previous releases.
When you open an AutoCAD drawing file in AutoCAD LT, AutoCAD LT uses
only the UCS from the current viewport. If you edit the drawing in AutoCAD
LT, and then save it and reopen it in AutoCAD, you may notice some discrep-
ancies in UCS usage. User coordinate systems that were set individually in
AutoCAD will probably change if the viewports that use them were activated
in the AutoCAD LT session.
Work with AutoCAD 2D and 3D Solid Object Shading
In AutoCAD, the
SHADEMODE command provides shading and wireframe
options for objects in the current viewport. Of the seven options available in
AutoCAD, only two are available in AutoCAD LT: 2D Wireframe and Hidden.
You can use the
SHADEMODE command in AutoCAD LT to turn rendering off
on viewports that were created in AutoCAD using the remaining five options.
This exposes the underlying geometry so you can easily edit drawings and
use the geometry with precision drawing tools such as object snaps.
Work with Custom and Proxy Objects
A custom object is a type of object created by an ObjectARX (AutoCAD run-
time Extension) application, which typically has more specialized capabili-
ties than standard AutoCAD objects. Custom objects include parametric sol-
ids (Autodesk Mechanical Desktop), intelligently interactive door symbols
(Autodesk Architectural Desktop), polygon objects (Autodesk Map), and asso-
ciative dimension objects (AutoCAD and AutoCAD LT).
In addition to Autodesk, many software vendors use ObjectARX to write pro-
grams that create graphical and nongraphical custom objects that are useful
in their AutoCAD applications.