Graphics Programs Reference
In-Depth Information
The RAY and XLINE commands are used to draw
construction lines
that guide
the construction of additional geometry. Drawing construction lines is less com-
mon in AutoCAD than in some other CAD programs. AutoCAD's many precision
techniques often provide more efficient methods for creating new geometry than
adding construction lines to your drawing does.
Toeing the line
The LINE command in AutoCAD draws a series of one or more visually connected line
segments. Although the lines appear to be physically connected, in fact, each
segment,
or piece of a line with endpoints, is a separate object. This construction doesn't seem
like a big deal until you try to move (or otherwise edit) a series of segments that you
drew with the LINE command; you must select every piece separately. To avoid such a
hassle, use polylines (described in the following section), not lines (or lines and arcs),
when you want the connected segments to act as a single object.
If you're used to drawing lines in other programs, you may find it confusing at first that
AutoCAD's LINE command doesn't stop after you draw a single segment. AutoCAD keeps
prompting you to specify additional points so that you can draw a series of (apparently)
connected segments. When you're finished drawing segments, just press Enter to finish
the LINE command.
Unlike a lot of the AutoCAD drawing commands, LINE doesn't offer a bunch of poten-
tially confusing options. It has a Close option to create a closed polygonal shape and an
Undo option to remove the most recent segment that you drew.
Like all drawing commands, LINE puts the line segments that it draws on the
current layer and uses the current color, linetype, lineweight, transparency, and
plot-style properties. When you're doing real drafting, as opposed to just experi-
menting, make sure of the following:
Think about setting these properties before you start drawing. Although you can
easily change an object's layer or other object properties, it's often more efficient
to set properties first. (I recommend that you set color, linetype, lineweight, trans-
parency, and, if you're using named plot styles, plot style to ByLayer.) See Chapter
