AutoCAD 2005 For Dummies (2004)

200 Part II: Let There Be Lines

Modify Objects Change Existing Objects Modify 3D Solids for a description of the other options on the Modify Solids Editing menu.

Figure 8-11:

Specialized solids editing commands.

Ending with Rendering

To my mother, who grew up on a farm in Iowa, rendering was what you did to fat to make it into lard. But in CAD, rendering is the process of illuminating a set of 3D objects with one or more imaginary lights and then creating a more- or-less realistic picture of the results. (No, computer programmers didn’t have lard on their minds when they borrowed the word rendering. Handdrawn pictures of building facades were called renderings long before computers got into the act.)

A single example of this technique is called a still rendering. Multiple frames strung together produce computer animation. The objects that you see in movies such as Toy Story or A Bug’s Life are first created as 3D models and then rendered frame by frame — a process that can take immense amounts of time even on ultrafast graphics workstations — to produce the beautifully, well-rendered images you see.

AutoCAD creates still renderings only. If you want to create animations, you need to use other software programs such as Discreet’s 3DS Max. Even if you use animation programs, AutoCAD can be useful for developing the initial 3D models.

Chapter 8: On a 3D Spree 201

Rendering has steadily improved in speed and usability as PCs have become faster, and programmers have improved their rendering algorithms. Rendering of simple scenes is now practical on a mainstream PC, and a fast personal computer can create some impressive images in a reasonable amount of time. Rendered images are useful for previewing how your models will work in real life and also can be powerful tools for sales and marketing communications for your company. A (rendered) picture can be worth quite a bit more than a thousand words.

To see how rendering works with the default options in AutoCAD, use the steps that follow. When you’re ready to get fancy, choose User’s Guide Create Realistic Images and Graphics Render 3D Objects for Realism in the AutoCAD online help system.

1. Create one or more 3D objects.

Use the steps in the previous section or use one of the sample 3D drawings in \Program Files\AutoCAD 2005\Sample.

Unless you want a monochromatic rendering, create the objects on several different layers that you’ve assigned different colors.

2.Choose View Render Render.

The Render dialog box appears, as shown in Figure 8-12.

Figure 8-12:

The Render dialog box and a rendered object.

202 Part II: Let There Be Lines

3.Ignore all the options and click the Render button.

You can get okay results without changing the options. When you click Render, AutoCAD renders the 3D objects. See Figure 8-12 for an example.

To make rendered images look less cartoonish, you need to apply materials to 3D objects and define different light sources. For more information, navigate to the Render 3D Objects for Realism help page mentioned just before the preceding steps and then look at Create Rendered Images Use Materials in Rendering and Create Rendered Images Use Lights in Rendering.

The SHADE command offers a simpler alternative to the RENDER command, without all the lighting, surface materials, and other options. To experiment with shading, choose any of the options on the View Shade menu. (To return to an unshaded view, choose View Shade 2D Wireframe.) As I mention earlier in this chapter, the 3DOrbit command’s right-click menu includes shaded modes that you can see even while navigating around your model in real time.

In addition to viewing rendered and shaded views on the screen, you can plot them, whether they’re in a paper space layout or in model space. Use the Shaded Viewport Options area of the expanded Plot dialog box to control this feature. Chapter 12 contains more information about plotting.

If you want to plot multiple rendered views (or a rendered view plus other nonrendered views), create a paper space layout with multiple viewports, as described in Chapter 3. As I mention earlier in this chapter, tiled model space viewports are great for creating and viewing 3D models, but you can plot only one model space viewport at a time. Use paper space layouts to compose multiple viewports for plotting purposes.

People who do a lot of rendering and want higher quality, photorealistic results usually use programs other than AutoCAD to render their models. Discreet 3DS Max, Autodesk VIZ, and McNeel’s are three popular photorealistic rendering programs. Most rendering programs can import 3D models from AutoCAD DWG files, but some people use specialized 3D modeling programs to do their modeling as well.

Part III

If Drawings

Could Talk

In this part . . .

Text, dimensions, and hatching have long been important clarifying elements in drafting. In AutoCAD, these

elements are flexible almost to a fault, and you can edit and update them quickly as you change the geometry beneath them. The text, dimension, and hatching annotations that you add “speak” about the geometry so that others can understand exactly what, how big, and how far.

After you’ve made some drawings that talk, you’ll probably send the message around by printing — or as CAD users call it, plotting — them. AutoCAD 2005 introduces a redesigned, streamlined Plot dialog box, which makes the often-complex task of plotting a little less daunting. Chapter 12 in this section is your passport to navigating the revised plot process, understanding how the legacy of AutoCAD plotting influences current practice, and most of all getting a good-looking, properly scaled plot onto paper.

Chapter 9

Text with Character

In This Chapter

Using text styles to control text appearance

Creating single-line and multiline text

Using fields and background masks with text

Making hanging indents

Editing text contents and properties

Creating tables

Checking spelling

Although it’s often true that “A picture is worth a thousand words,” it’s also true that adding a few words to your drawing can save you from having to draw a thousand lines and arcs. It’s a lot easier to write “Simpson

A35 framing clip” next to a simple, schematic representation of a clip than to draw one in photorealistic detail and hope that the contractor can figure out what it is!

Most CAD drawings include some text in the form of explanatory notes, objects labels, and titles. This chapter demonstrates how to add text to drawings and shows you how to take advantage of AutoCAD text styles and the spelling checker. Chapter 10 covers text that’s connected with dimensions and leaders.

In most cases, adding text, dimensions, and other descriptive symbols is something that you should do later in the drafting process, after you’ve drawn at least some of the geometry. In CAD drawings, text and other annotations usually are intended to complement the geometry, not to stand alone. Thus, you generally need to have the geometry in place before you annotate it. Many drafters find that it’s most efficient to draw as much geometry as possible first, and then add text labels and dimensions to all the geometry at the same time. In this way, you develop a rhythm with the text and dimensioning commands, instead of bouncing back and forth between drawing geometry and adding annotations. (It helps if you hum “I’ve got rhythm . . .” while sliding the mouse back and forth in time.)

206 Part III: If Drawings Could Talk

Getting Ready to Write

In AutoCAD, adding text to a drawing is only slightly more complicated than adding it to a word processing document. Here are the steps:

1.Create a new AutoCAD text style, or select an existing style, that includes the font and other text characteristics you want to use.

2.Make an appropriate text layer current.

3.Run one of these commands to draw text:

•mText draws paragraph (also called multiline) text.

•TEXT draws single-line text.

4.Specify the text alignment points, justification, and height.

5.Type the text.

You’re probably familiar with most of these steps already — especially if you’ve ever used a word processor. In the next few sections of this chapter, I review the particularities of AutoCAD text styles, the two kinds of AutoCAD text, and ways of controlling height and justification.

Simply stylish text

AutoCAD assigns text properties to individual lines or paragraphs of text based on text styles. These text styles are similar to the paragraph styles in Microsoft Word: They contain font and other settings that determine the look and feel of text. An AutoCAD text style includes

The font

A font height, which you can set or leave at 0 for later flexibility

Special effects such as italic

Really special effects such as vertical and upside down, which almost nobody uses

Before you add text to a drawing, use the Text Style dialog box to select an existing style or create a new one with settings that are appropriate to your purpose. Your AutoCAD notes may generate strange responses (or no response at all) if they appear in Old Persian Cuneiform or the Cyrillic alphabet.

Most drawings require very few text styles. You can create one style for all notes, object labels, and annotations, and another one for special titles. A title block may require one or two additional fonts, especially if you want to mimic the font used in a company logo or project logo.

Chapter 9: Text with Character 207

As with layers, your office may have its own text style standards. If so, you’ll make everyone happy by following those standards. One of the best ways to make your use of text styles efficient and consistent is to create them in a template drawing that you use to start new drawings. (If your office is well organized, it may already have a template drawing with the companyapproved styles defined in it.) See Chapter 3 for information about creating

and using templates. Another handy technique is to copy existing text styles from one drawing to another by using the DesignCenter palette. See Chapter 4 for instructions.

Font follies

When you create a text style in AutoCAD, you have a choice of a huge number of fonts. AutoCAD can use two different kinds of fonts: native AutoCAD SHX (compiled SHape) fonts and Windows TTF (TrueType) fonts:

SHX: In the Text Style dialog box, SHX font names appear with a drafting compass to the left of the name. SHX fonts usually provide better performance because they’re optimized for AutoCAD’s use.

TTF: In the Text Style dialog box, TrueType font names appear with a TT symbol to the left of name. TTF fonts give you more and fancier font options, but they slow down AutoCAD when you zoom, pan, and select and snap to objects. TrueType fonts also can cause greater complications when you exchange drawings with other AutoCAD users. Chapter 16 describes the special procedure that you need to use in order to install custom TrueType fonts.

It’s okay to use a TrueType font sparingly for something like a title block logo, but in general, you should stick with standard AutoCAD SHX fonts whenever possible.

The most popular AutoCAD font is ROMANS.SHX (Roman Simplex). (You may also run into SIMPLEX.SHX, an older version of Roman Simplex.) ROMANS.SHX is a good, general-purpose font for drafting in AutoCAD. Avoid complicated, thick fonts. They can slow down AutoCAD, and they’re usually more difficult to read than the simpler fonts. Remember, you’re doing CAD here — not fancy graphic design or reproduction of medieval manuscripts!

Whenever possible, avoid custom fonts, which are font files that don’t come with AutoCAD or AutoCAD LT (both programs come with the same fonts). AutoCAD installs its standard SHX fonts into the C:\Program Files\AutoCAD 2005\Fonts folder — as long as you haven’t added any custom fonts to that folder, you can refer to it for a list of standard fonts. If you use a custom font, exchanging your drawings with other people will be more complicated. If you’re compelled to use a custom font, make a note of it and remember either to send it whenever you send the DWG file (assuming that the font isn’t copyrighted, which many custom fonts are) or to warn the recipients that the text

208 Part III: If Drawings Could Talk

will appear different on their systems. It’s far less hassle to eschew custom fonts altogether. See Chapter 16 for additional information about how to deal with fonts when you send and receive drawings.

Get in style

The following steps describe how to select an existing text style or create a new one before you enter text into a drawing. (If you want to experiment with an existing drawing that contains a variety of text styles, you can use \Program Files\AutoCAD 2005\Sample\Hummer Elevation.dwg.)

1.Choose Format Text Style.

The Text Style dialog box appears, as shown in Figure 9-1.

2.In the Style Name drop-down list, select each style in turn to see what text styles have been created in this drawing.

Note the font name and look at the Preview panel to get a feel for what the different fonts look like.

3.If you find a suitable text style, select it in the Style Name drop-down list and then skip to Step 9.

What constitutes a suitable text style depends on industry practices, office standards, and personal preferences about how the text should look. The information in preceding sections may help you decide. If not, ask an experienced drafter in your office or look at some printed drawings and try to match the text on those.

The selected text style name becomes the current style.

4.If you don’t find a suitable text style, or if you prefer to create your own text style, click New.

The New Text Style dialog box appears, with an edit box for you to type a name.

Figure 9-1:

Text with style.

Chapter 9: Text with Character 209

5.Type a name for your new text style and then click OK.

Your new text style is added to the Style Name list and becomes the current style.

6.Choose a font from the Font Name list.

ROMANS.SHX is the best all-purpose font for most drafting work. If you’d like to use a different font, review the font suggestions and warnings in the previous section.

The font that you choose becomes the font that’s assigned to your new text style.

7.Set the remaining text style settings as shown in Figure 9-1: Height = 0.0, Width Factor = 1.0, Oblique Angle = 0.0, and all four check boxes unchecked.

A text style height of 0.0 makes the style variable height, which means that you can specify the height separately for each single-line text object. Assigning a fixed (that is, nonzero) height to a text style forces all singleline text using the style to be the same height. Variable height styles are more flexible, but fixed height styles usually make it easier to draw text of consistent height. The decision to use variable height versus fixed height styles is another aspect of text that depends on office practice, so if you work with other AutoCAD users, ask around.

8.Click Apply.

9.Click Close.

The Text Style dialog box closes, and the text style that you selected or created is now the current style for new text objects.

Taking your text to new heights

In Chapter 3, I describe the importance of choosing an appropriate drawing scale when you set up a drawing. I warn you that you need to know the drawing scale factor for tasks described in other chapters of this book. This is one of those chapters, and I’m about to explain one of those tasks!

Drawing scale is the traditional way of describing a scale with an equal sign or colon — for example 1⁄4” = 1’–0”, 1:20, or 2:1. The drawing scale factor represents the same relationship with a single number such as 48, 20, or 0.5. The drawing scale factor is the multiplier that converts the first number in the drawing scale into the second number.

One of the things that distinguishes knowledgeable CAD users is that they always know the drawing scale factor of any drawing they’re working on. Make it a point to determine the drawing scale factor of a drawing before you add text to it.