Autodesk 00128-051462-9310 - AUTOCAD 2008 COMM UPG FRM 2005 DVD, User Manual

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Construction Lines
Construction lines (also known as xlines) are temporary linework entities that can be used as references when creating
and positioning other objects or linework. For example, you can use construction lines to prepare multiple views of
the same item, or create temporary intersections to serve as object snaps.
Construction lines are either circles or straight lines that extend to infinity in both directions. In either case, they do
not change the total area of the drawing and have no effect on zooming or viewports. You can move, rotate, copy, or
delete construction lines just like other objects.
The regular AutoCAD construction line functionality is still available via the XLINE command. However, the AutoCAD
Architecture construction line feature is designed to give you a more intuitive way of drawing construction lines based
on the geometry of existing objects or linework. No command line entry is required. You access the Construction Line
command by clicking the button on the Shapes toolbar. The XLINE layer key is used by default for all construction
lines created with this command.
In most cases, you would probably want to draw construction lines based on segments of existing objects, but you can
also draw them by specifying any two points in the drawing area, without regard to existing objects or linework.
Creating Construction Lines From Existing Objects/Linework
Use this procedure to create a construction line based on the geometry of any straight, arced, or circular segment of
any object or linework, except hatches, splines, and ellipses. If based on a straight segment, the resulting construction
line is a straight line that extends to infinity in both directions; if based on an arced or circular segment, the construction
line is a circle.
1 On the Shapes toolbar, click .
2 In the drawing area, move the cursor over the segment on which you want to base your construction line
(the “construction line base”).
A preview of the construction line is displayed.
3 Click to display an offset indicator, which dynamically shows the distance between the preview line and
the construction line base.
4 Either drag the preview line to the desired distance, and click to position the construction line, or enter
the desired distance and press
ENTER
.
Drawing a construction line at a zero offset based on a straight wall segment
1526 | Chapter 33 Detail Drafting Tools