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You aren’t likely to need any of these three commands very often, but if you do, look up the command name in the online help system.

DIMREASSOCIATE: If you have dimensions that aren’t currently geometrydriven (probably because they were created in older versions of AutoCAD) or are associated with the wrong objects, you can use the DIMREASSOCIATE command (Dimensions Reassociate Dimensions) to associate them with points on the objects of your choice.

DIMDISASSOCIATE: You can use the DIMDISASSOCIATE command to sever the connection between a dimension and its associated object.

DIMREGEN: In a few special circumstances, AutoCAD doesn’t automatically update geometry-driven associative dimensions (maybe Autodesk should call them “usually geometry-driven but occasionally asleep at the wheel associative dimensions”). In those cases, the DIMREGEN command will fix things.

Pointy-Headed Leaders

No, I’m not talking about your boss (or about you, if you happen to be the boss). I’m talking about arrows that point from your comment to the object or area about which you’re commenting. AutoCAD treats leaders as a special kind of dimension object (no jokes about dimwitted leaders, now). You can draw leaders and text at the same time easily by using the qLEader (Quick Leader) command, as described in the following steps.

qLEader is an improved version of the old LEADER command, which remains in AutoCAD 2005 for compatibility reasons. I recommend that you use qLEader instead of LEADER. Fortunately, the AutoCAD 2005 Dimension menu and toolbar choices run the qLEader command.

qLEader is another one of those annoying AutoCAD commands that prompts you for some information on the command line and some in a dialog box. Pay close attention to the command line prompts throughout this example:

1.Set a layer that’s appropriate for dimensions current.

See Chapter 4 for details.

2.Set a dimension style that’s appropriate for your needs current.

Choose an existing dimension style from the drop-down list on the Styles toolbar, or create a new style by using the procedure in the section, “Creating and managing dimension styles,” earlier in this chapter.

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3.Choose Dimension Leader or click the Quick Leader button on the

Dimension toolbar.

The command line prompts you to select the first leader point — that is, the arrowhead point — and gives you the option of changing leader settings first:

Specify first leader point, or [Settings] <Settings>:

If you want to draw curved rather than straight leader lines or choose a different leader arrowhead style, press Enter now to open the Leader Settings dialog box.

4.Pick a point that you want to point to.

If you use an object snap mode, such as Nearest or Midpoint, to pick a point on an object, AutoCAD associates the leader with the object. If you later move the object, AutoCAD updates the leader so that it points to the new location.

The command line prompts you for the next point — AutoCAD draws a shaft from the arrowhead to this point:

Specify next point:

5.Pick a second point.

If you pick a second point that’s too close to the arrowhead point, AutoCAD doesn’t have enough room to draw the arrowhead, and thus omits it.

AutoCAD repeats the next point prompt so that you can draw a multisegment shaft if you want to:

Specify next point:

6.Pick one more point if you want to, or press Enter if you want a leader with a single shaft.

Pressing Enter tells the qLEader command that you’re finished selecting the points that define the leader shaft. By default, the qLEader command lets you pick up to three points (the arrowhead point and two more points). You can change this behavior in the Leader Settings dialog box (refer to Step 3).

The command line prompts you to specify the width for word-wrapping the text that you’ll attach to the leader:

Specify text width <0.0>:

The default text width, 0.0, turns off word-wrapping and displays your text on a single line. You can type a width or point and click with the mouse.

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Turning off word-wrapping works fine for short notes that fit on one line. If you think your note may be longer, specify a width instead of accepting the default value of 0.0.

7.Press Enter to suppress word-wrapping, or move the cursor to the right or left to specify a width for word-wrapping; then click.

The command line prompts you to type a short note directly at the command line, or press Enter to type your note in the Multiline Text Editor window:

Enter first line of annotation text <Mtext>:

8.Press Enter to open the Multiline Text Editor window.

9.Enter your comment.

10.Click OK.

The Multiline Text Editor window closes and adds your comment to the drawing, next to the leader.

Figure 10-11 shows several different leaders with notes.

Figure 10-11:

All leaders and no followers.

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If both the leader arrowhead and the text are the wrong size or appear to be missing entirely, the dimension scale isn’t set correctly in the drawing. (As I warn you earlier, AutoCAD treats leaders as a special kind of dimension object.) See Chapter 3 for detailed instructions on how to set the dimension scale. After you set the dimension scale properly, erase and re-create the leader and text.

If you add a comment to a drawing and later decide that the comment merits a leader, you can use the qLEader command to draw the leader so that the end of the shaft ends up in the vicinity of the existing text object. Then, when the Multiline Text Editor window appears (Step 8 in the previous steps), click OK without entering any new text.

A leader and the text that you draw with it are partially associated with each other. When you move the text, the leader’s shaft follows. Unfortunately, the converse isn’t true — moving the leader or one of its vertices doesn’t cause the text to follow.

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Chapter 11

Down the Hatch

In This Chapter

Adding hatching to your drawings

Copying existing hatches

Using predefined and user-defined hatch patterns

Making solid and gradient fills

Scaling hatches properly

Choosing hatching boundaries

Editing hatches

If you were hoping to hatch a plot (or plot a hatch), see Chapter 12 instead. If you want to hatch an egg, buy my companion book, Raising Chickens For Dummies. If you need to fill in closed areas of your drawings with special pat-

terns of lines, this is your chapter.

Drafters often use hatching to represent the type of material that makes up an object, such as insulation, metal, concrete, and so on. In other cases, hatching helps emphasize or clarify the extent of a particular element in the drawing — for example, showing the location of walls in a building plan, or highlighting a swampy area on a map so you know where to avoid building a road. Figure 11-1 shows an example of hatching in a structural detail.

An AutoCAD hatch is a separate object that fills a space, that has an appearance dictated by the hatch pattern assigned to it, and that is associated with the objects that bound the space, such as lines, polylines, or arcs. If you move or stretch the boundaries, AutoCAD normally updates the hatching to fill the resized area.

Don’t go overboard with hatching. The purpose of hatching is to clarify, not overwhelm, the other geometry in the drawing. If your plots look like a patchwork quilt of hatch patterns, it’s time to simplify.

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Figure 11-1:

A big batch o’hatch.

Hatching is another kind of annotation of your geometry, similar in purpose to text and dimensions. As I describe at the beginning of Chapter 9, you’ll usually be more efficient if you save annotation for later in the drafting process. Draw as much geometry as possible first, and then hatch the parts that require it. In other words, batch your hatch.

Hatch . . . Hatch . . . Hatchoo

This section outlines the steps you use to add hatching to a drawing with the Boundary Hatch and Fill dialog box, shown in Figure 11-2. You can use this information to get started quickly with hatching. When you need more information about any part of the process, jump to the relevant sections of “Pushing the Boundary (of) Hatch,” later in this chapter.

The following steps show you how to hatch an enclosed area by using the “pick points” method of selecting the hatch area:

1.Open a drawing containing geometry that forms fully closed boundaries, or draw some boundaries by using the drawing commands I describe in Chapter 5.

The areas you want to hatch must be completely enclosed. The Circle, POLygon, and RECtang commands, and the Line and PLine commands with the Close option, make great hatch boundaries (see Chapter 5 for details).

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Figure 11-2:

The Hatch tab of the Boundary Hatch and Fill

dialog box.

2. Set an appropriate layer current, as described in Chapter 4.

It’s usually best to put hatching on its own layer.

3.Start the bHatch command by clicking the Hatch button on the Draw toolbar.

The Boundary Hatch and Fill dialog box appears.

For historical reasons, AutoCAD 2005 also has a HATCH command, which prompts you at the command line instead of opening a dialog box. Trust me — you want the bHatch command’s dialog box.

4.Choose Predefined, User Defined, or Custom from the Type drop-down list.

Predefined or User Defined works best for most purposes. See the next section for details.

5.If you chose Predefined or Custom in the previous step, select any predefined or custom hatch pattern from the Pattern drop-down list or the Pattern button just to the right of it. If you chose User Defined, you don’t need to choose a pattern.

6.Specify an Angle and Scale for the hatch pattern (or, if you chose User Defined in Step 4, specify Angle and Spacing).

See “Getting it right: Hatch angle and scale,” later in this chapter, for more information.

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7. Click the Pick Points button.

The Boundary Hatch and Fill dialog box (temporarily) disappears, and your drawing reappears with the following prompt at the command line:

Select internal point:

8.Select a point inside the boundary within which you want to hatch by clicking it with the mouse.

AutoCAD analyzes the drawing and decides which boundaries to use. In a complex drawing, this analysis can take several seconds. AutoCAD highlights the boundary that it finds.

If AutoCAD highlights the wrong boundary, right-click, choose Clear All from the cursor menu, and try again.

9.Right-click anywhere in the drawing area and choose Enter from the cursor menu to indicate that you’re finished selecting points.

The Boundary Hatch and Fill dialog box reappears.

10.Click the Preview button to preview the hatch.

The Boundary Hatch and Fill dialog box (temporarily) disappears again, and AutoCAD shows you what the hatch will look like.

Pick or press Esc to return to dialog or <Right-click to

accept hatch>:

11.Click anywhere in the drawing area to return to the Boundary Hatch and Fill dialog box.

12.Adjust any settings and preview again until you’re satisfied with the hatch.

13.Click OK.

AutoCAD hatches the area inside the boundary. If you modify the boundary, the hatch automatically resizes to fill the resized area.

Occasionally, AutoCAD gets confused and doesn’t resize a hatch after you resize the boundary. If that happens, erase and then re-create the hatch in the resized area.

Pushing the Boundary (of) Hatch

The remainder of this chapter shows you how to refine the techniques presented in the preceding section. I describe how to copy existing hatching, take advantage of the various options in the Boundary Hatch and Fill dialog box, and choose more complicated hatching boundaries.

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Catch a hatch: Copying hatch properties

One slick way to hatch is by using the Inherit Properties button in the Boundary Hatch and Fill dialog box to copy hatch properties from an existing hatch object. Think of it as point and shoot hatching. If someone — such as you — added some hatching in the past that’s just like what you want to use now, click the Inherit Properties button and pick the existing hatching.

Inherit Properties updates the hatch pattern settings in the Boundary Hatch and Fill dialog box to make them the same as the existing hatch pattern object that you picked. You can

use the cloned hatch pattern specifications as is or modify them by making changes in the Boundary Hatch and Fill dialog box.

Consistency is a good thing in drafting, especially in computer-aided drafting, in which some or all your drawing may be used for a long time. Thus it’s good to use the same hatch patterns, scales, and angles for the same purposes in all your drawings. Find out whether your project, office, company, or profession has hatching standards that apply to your work.

Hatch from scratch

You can use predefined, user-defined, or custom hatch patterns. Most of the time, you’ll choose either predefined or user-defined hatch patterns, unless some generous soul gives you a custom pattern. The next four sections describe the hatch pattern type choices.