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Drawing polylines composed of straight segments is much like drawing with the Line command, as shown in the steps in this section. The PLine command has a lot more options, however, so watch the prompts. If the Dynamic Input feature is on, press the down-arrow key to see the options listed near the cursor, or right-click to display the PLine right-click menu, or simply read the command line.

To draw a polyline composed of straight segments, follow these steps:

1  Click the Polyline button on the Draw panel of the Ribbon, or type PL at the command line and press Enter.AutoCAD starts the PLine command and prompts you to specify a start point.

2 Specify the starting point by clicking a point or typing coordinates.Now you truly do need to read the command line, because the Dynamic Input tooltip at the cursor doesn’t display any of the options. You can right-click or press the down-arrow key to see a list of the options at the cursor, as shown in Figure 6-2, but it’s usually faster to use the command line.AutoCAD displays the current polyline segment line width at the command line and prompts you to specify the other endpoint of the first polyline segment:Current line-width is 0.0000Specify next point or [Arc Halfwidth Length Undo Width]:

3 If the current line width isn’t zero, you can change it to zero by typing W to select the Width option and then entering 0 as the starting and ending widths, as shown in this command-line sequence: Specify next point or [Arc Halfwidth Length Undo Width]: WSpecify starting width <0.0000>: 0Specify ending width <0.0000>: 0Specify next point or [Arc Halfwidth Length Undo Width]: Despite what you may think, a zero-width polyline segment isn’t the AutoCAD equivalent of drawing with invisible ink. Zero width means, “Display this segment using the normal, single-pixel width on the screen, and print as thin as possible.” How can you tell when your pen has run out of invisible ink? You can see the writing.

4 Specify additional points by clicking or typing.After you specify the second point, AutoCAD adds the Close option to the prompt. The command line showsSpecify next point or [Arc Close Halfwidth Length Undo Width]: What you do next can get a little weird. If you invoke the Close option after selecting only the first and second points, PLine doubles back on itself and creates the second segment back over the first, unlike the Line command, which won’t. Normal practice would be to not invoke Close until you have created at least two non-collinear segments.

5 Pick several points to create several line segments, and then enter W to start the Width option. Then set a new width, as shown in this command line sequence: Starting width <0.0000>: 5Specify ending width <5.0000>: Press Enter

6 Pick several more points and note the line width of the new segments.

7 Set the Width option again: Starting width <5.0000>: 15Specify ending width <0.0000>: 0

8 Pick another point.You just created a cool arrowhead! Any time AutoCAD prompts for a length or distance, you can either type a value or you can show it what you want by picking two points in the drawing.

9 After you finish drawing segments, press Enter to leave the figure open, or type C and press Enter to close it back to the start.AutoCAD draws the final segment and miters all the corners perfectly.

FIGURE 6-2: The optional extras.

After you create a polyline, you can adjust its segments by grip-editing any of the vertex points. See Chapter 11 for details on grip editing.

In the following steps, I spice things up by adding an arc segment to a polyline.