New Commands in AutoCAD 2010: Part 7
Reversing Direction
by Ralph Grabowski
Introduction
Sometimes the most useful new commands are the simplest. For instance, the new
Reverse command reverses the direction of lines, polylines, splines, and helixes. Most
of the time, the direction of these objects makes no difference. Where it does have an
impact is in these areas:
− Upside down linetype text.
− Reverse the order of vertices in polylines and splines.
− Change the direction in which 3D entities are made from polylines, helixes,
and so on.
In this tutorial, you draw two lines in opposite directions, apply linetypes, and then reverse their
directions to see the effect of the Reverse command.
Tutorial: Reversing Linetypes
1.
2.
Start AutoCAD 2010 with a new drawing.
Draw two lines with the Line command, but in opposite directions.
TIP The direction of a line is determined by the start and end pick points, as
illustrated by the figure.
Figure 1: Two lines drawn in opposite directions.
3.
Use the Linetypes command to apply the gas line linetype, as follows:
a. From the ribbon's Home tab, click the Linetype control, and then choose
Other.
b. In the Linetype Manager dialog box, click Load.
c. In the Load or Reload Linetypes dialog box, select GAS_LINE, and then click
OK. (Press "g" to get to "gas_line" in this long list of linetype names quickly.)
Figure 2: Linetype dialog boxes.
d. Back in the Linetype Manager dialog box, click OK to exit the dialog box.
e. Select the two linetypes. (Press Ctrl+A to select them both quickly.)
f. From the Linetype control, select "GAS_LINE".
Notice that the two lines take on the GAS_LINE linetype, but that the text is upside
down for one of them. (If the text is too small, change the value of LtScale to 5.)
Figure 3: Linetype text is upside down on one line.
4.
Use the Reverse command to make the text rightside up. (Technically, this
command reverses the endpoint of the line segment, causing the linetype to display in
the opposite direction, making the text look rightside up.)
Start the Reverse command in one of these ways:
− At the command prompt, enter Reverse, or...
− Click the ribbon's Home tab, and then choose Reverse button in the Modify
panel.
Figure 4: Selecting the Reverse command from the ribbon.
5.
At the command line (or dynamic input), AutoCAD prompts you to select reversible
objects:
Command: _reverse
Select line, polyline, spline or helix to reverse direction:
Select objects: (Select the line with upside down text.)
6.
Press Enter to exit the command:
Select objects: (Press Enter.)
Object direction has been reversed.
Notice that the linetype text is now rightside up.
Figure 5: One line is reversed in direction.
7. This ends the tutorial; there is no need to save the drawing.
Test Yourself
1.
What is the purpose of the Reverse command?
a. There is no such command in AutoCAD.
b. It toggles the background color of the drawing area between white and black.
c. It reverses the effect of the last command entered into AutoCAD.
d. It reverses the direction of specific open objects.
2.
Why would you want to use the Reverse command?
a. Never; the command does not exist.
b. To reverse the display order of layers in drawings.
c. To reverse the plot direction of drawings.
d. To reverse the direction of linetype text.
3.
The Reverse command reverses arcs, dimensions, and revolved surfaces.
True/False.
4.
The Reverse command reverses helixes, polyline arcs, and splines.
True/False
5.
What determines the direction of line segments?
a. The clockwise and counter clockwise settings in the Units command.
b. The order in which the start and end points are drawn.
c. Whether you live in the Northern or Southern hemisphere.
d. Whether they are drawn in months containing the letter R.
Answers:
1.
2.
3.
4.
5.
d. It reverses the direction of specific open objects.
d. To reverse the direction of linetype text.
False
True
b. The order in which the start and end points are drawn.