3. Click the Select Objects button, and then select one or more objects. Press Enter to end object selection and return to the Array dialog box.
4. Make sure that the Rectangular Array radio button is selected.
If rectangular arrays seem too square, choose the cool Polar Array radio button instead and experiment with the other array option.
5. Fill in the five edit boxes: Rows, Columns, Row Offset, Column Offset, and Angle of Array.
The Rows and Columns numbers include the row and column of the original objects themselves. In other words, entries of 1 don’t create any new objects in that direction. The Row Offset and Column Offset measurements are the distances between adjacent rows and columns.
6. Click Preview.
AutoCAD shows what the array will look like by using your current settings and displays a dialog box with Accept, Modify, and Cancel buttons.
7. Click the Accept button if you’re satisfied with the array, or the Modify button if you want to change the array parameters.
You use Offset to create parallel copies of lines, polylines, circles, arcs, or splines. Follow these steps to use OFfset:
1. Click the Offset button on the Modify toolbar.
AutoCAD prompts you for the
Specify offset distance or [Through] <Through>:
2. Type an offset distance and press Enter.
Alternatively, you can indicate an offset distance by picking two points on the screen. If you choose this method, you normally should use object snaps to specify a precise distance from one existing object to another.
AutoCAD prompts you to select the object from which you want to create an offset copy:
Select object to offset or <exit>:
3. Select a single object, such as a line, polyline, or arc.
Note that you can select only one object at a time with the OFfset command. AutoCAD asks where you want the offset object:
Specify point on side to offset:
4. Point to one side or the other of the object and then click.
It doesn’t matter how far away from the object the cursor is when you click. You’re simply indicating a direction.
AutoCAD repeats the Select object prompt, in case you want to offset other objects by the same distance:
Select object to offset or <exit>:
5. Go back to Step 3 if you want to offset another object, or press Enter if you’re finished offsetting objects for now.
Figure 6-11 shows the OFfset command in progress.
Figure 6-11: Offsetting a line.
If you want to offset a series of connected lines (for example, a rectangular house plan outline or one side of a pathway on a map), make sure that you either draw it as a polyline or convert the individual line and/or arc segments into a polyline with the PEdit command. If you draw a series of line segments with the Line command and then try to offset it, you have to pick each segment and offset it individually. Even worse, the corners usually aren’t finished off in the way that you’d expect, because AutoCAD doesn’t treat the segments as connected. You avoid all these problems by offsetting a polyline, which AutoCAD does treat as a single object. See Chapter 5 for more information about the differences between lines and polylines.
The commands in this section — TRim, EXtend, BReak, Fillet, and CHamfer — are useful for shortening and lengthening objects and for breaking them in two.
TRim and EXtend are the twin commands for making lines, polylines, and arcs shorter and longer. They’re the yin and yang, the Laurel and Hardy, the Jack Sprat and his wife of the AutoCAD editing world. The two commands and their prompts are almost identical, so the following steps cover both. I show the prompts for the TRim command; the EXtend prompts are similar:
1. Click the Trim or Extend button on the Modify toolbar.
AutoCAD prompts you to select cutting edges that will do the trimming (or, if you chose the EXtend command, boundary edges for extending to):
Current settings: Projection=UCS, Edge=None
Select cutting edges ...
Select objects:
2. Select one or more objects that will act as the knife for trimming objects or the wall to which objects will be extended. Press Enter to end object selection.
Figure 6-12 shows a cutting edge (for TRim) and a boundary edge (for EXtend).
Figure 6-12: Anatomy of the TRim and EXtend operations.
AutoCAD prompts you to select objects that you want to trim or extend:
Select object to trim or shift-select to extend or
[Project/Edge/Undo]:
3. Select a single object to trim or extend. Choose the portion of the object that you want AutoCAD to trim away or the end of the object that’s closer to the extend-to boundary.
AutoCAD trims or extends the object to one of the objects that you selected in Step 2. If AutoCAD can’t trim or extend the object — for example, if the trimming object and the object to be trimmed are parallel — the command line displays an error message such as Object does not intersect an edge.
TRim and EXtend normally allow you to select only one object at a time for trimming or extending. The one exception is that you can type F and press Enter to use the Fence object selection mode (refer to Table 6-1). Fence is useful for trimming or extending a large group of objects in one fell swoop.
The command line continues to prompt you to select other objects to trim or extend:
Select object to trim or shift-select to extend or
[Project/Edge/Undo]:
4. Choose additional objects, or press Enter when you’re finished trimming or extending.
If you accidentally trim or extend the wrong object and you’re still in the TRim or EXtend command, type U and press Enter to undo the most recent trim or extend.
The example in Figure 6-12 shows trimming to a single cutting edge, in which the end of the trimmed lines gets lopped off. Another common use of the TRim command is for trimming out a piece of a line between two cutting edges. In the two-cutting-edges scenario, TRim cuts a piece out of the middle of the trimmed line.
The LENgthen command provides other useful ways to make lines, arcs, and polylines longer (or shorter). You can specify an absolute distance (or “delta”) to lengthen or shorten by, a percentage to lengthen or shorten by, or a new total length. Look up “LENGTHEN command” in AutoCAD’s help system for more information.
The BReak command isn’t what you use before heading out for coffee. It’s for breaking pieces out of — that
