Lesson 8: More Complex Lines - Polylines

Overview

Following this lesson, you will:

• Know how to draw Polylines: The PLine command

• Know how to edit Polylines: The PEdit command

• Know how to convert Lines to Polylines

• Know how to convert Polylines to Lines: The Explode command

• Be familiar with AutoCAD's Inquiry Commands

  • List

  • Dist

  • Area

  • ID

Back in Lesson 6, we discussed ways of differentiating among the various parts of a drawing using colors, linetypes, and layers . We also used lineweights to add width, but we had problems with them because lineweight isn't a true WYSIWYG property. In that lesson, I promised to show you how to create lines with true WYSIWYG width. Once you've conquered width “ through polylines “ you can combine wide lines with linetypes and layers for more complex drawings.

You can draw lines with width using the PLine command. We call these lines polylines, not for their ability to show width, but for their ability to be drawn as multi-segmented lines. That is, polylines can contain many lines and still be treated as a single unit (much as you've already seen with polyline rectangles and polygons).

Prior to R14, polylines often confused the AutoCAD user because of the massive amounts of information they contained. They also dramatically increased the size of a drawing with stored information that was often never used or needed. For this reason, AutoCAD created the light weight polyline or lwpolyline. Capable of containing most of the information available to the polyline, the lwpolyline is much more condensed, presents its information via the List command (Section 8.2.1) in a much more logical and understandable manner, and takes up much less drawing memory. The PLine command will actually draw an lwpolyline (pronounced "L-W- polyline") and convert automatically to a polyline if the need arises to function as the older polylines did.

Note  

Additionally, polylines can carry information. These are known as smart polylines but are beyond the scope of this text. For more information on smart polylines, see an AutoCAD customization text.