Expert Training

As with all computer documents that you work on, get in the habit of saving your current AutoCAD drawing regularly. I recommend every 10 minutes or so. Although AutoCAD’s automatic drawing save feature is useful as a secondary backup save, you shouldn’t rely on it exclusively. (AutoCAD creates automatic save files with inscrutable names like Drawing1_1_1_1478.bak and puts them in the folder specified by the Automatic Save File Location setting on the File tab of the Options dialog box.) Save your drawing and save yourself the pain of lost work and the hassle of trying to locate the right automatic save file.
Backing up your data is prudent advice for any important work that you do on a computer, but it’s doubly prudent for CAD drawings. A set of CAD drawings is a lot harder and more time-consuming to re-create than most other computer documents. Unless you’re willing to lose more than a day’s worth of work, develop a plan of daily backups onto tape, CD-RW (CD ReWritable) discs, or another high-capacity medium.
Warning Don’t be lulled into complacency by the increasing reliability of hard disks. Although hard disk failure is increasingly rare, it still happens, and if it happens to you sans backup, you’ll quickly understand the full force of the phrase “catastrophic failure.” Also, backups aren’t just protection against disk failure. Most of the time, backups help you recover from “pilot error” — accidentally erasing a file, messing up a drawing with ill-advised editing, and so on. Even if you’re conscientious and never make mistakes, there’s a good chance that someone else in your office who has access to your DWG files hasn’t quite achieved your exalted level of perfection. Protect your work and minimize recriminations with regular backups.

Overview
At various times, you probably need to transfer information from one kind of document to another. You even may have taken the CAD plunge because you want to import AutoCAD drawing data into your word processing or other documents. If so, this chapter is for you. It covers exchanging AutoCAD drawing data with other programs — what works, what doesn’t, and how to do it. I also tell you when to give up and reach for the scissors and glue.
Remember This chapter frequently mentions vector and raster graphics file formats:
A vector format stores graphics as collections of geometrical objects (such as lines, polygons, and text). Vector graphics are good for high geometrical precision and for stretching or squeezing images to different sizes. These two characteristics make vector formats good for CAD.
A raster format stores graphics as a series of little dots, or pixels. Raster graphics are good for depicting photographic detail and lots of colors.
Warning Exchanging AutoCAD drawing data with other programs sometimes works great the first time you try it. Sometimes, you have to try a bunch of techniques or exchange formats to get all the data to transfer in an acceptable way. Occasionally, no practical exchange method exists for preserving formatting or other properties that are important to you. Where your exchange efforts fall in this spectrum depends on the kind of drawings you make, the other programs you work with, and the output devices or formats that you use. I provide recommendations in this chapter, but be prepared to experiment.

DWG, AutoCAD’s native file format, is the best format for exchanging drawings with other AutoCAD or LT users. Use the SAVE and SAVEAS commands to create DWG files and the OPEN command to open them.
AutoCAD LT AutoCAD LT can’t create every kind of object that AutoCAD can — raster attachments and most 3D objects, for example — but it can successfully read and save DWG files that contain these objects.
Warning AutoCAD 2004 can’t save to the AutoCAD Release 14 DWG format. Apparently, the Autodesk bigwigs figure that the best way to persuade R14 users to upgrade is to make their lives as inconvenient and isolated as possible! If you need to send AutoCAD 2004 drawings to AutoCAD R14 users, save them in R12 DXF format instead of a DWG format. (See the “DXF” section for instructions.)

AutoCAD LT Round-trip DWG fare
The most demanding — and elusive — kind of data exchange is called round-trip transfer. Round-trip means that you create and save a file in one program, edit and save it in another program, and then edit and save it in the first program again. A perfect round-trip is one in which all the data survives and the users of both programs can happily edit whatever they want to. Unfortunately, the perfect round-trip, like the perfect visit to your cousins, rarely happens.
In CAD, round-trip transfer becomes an issue when two people want to work on the same drawings with different CAD programs. AutoCAD and AutoCAD LT have excellent round-trip compatibility, as Chapter 1 explains. Expect a bumpier road if you’re exchanging drawings with users of other CAD programs. Perform some test transfers before you assume that your drawings can get from here to there and back again unscathed.
Autodesk does not document the native AutoCAD DWG file format, and recommends that all file exchanges between AutoCAD and other CAD programs take place via DXF files (see the next section). But several companies have reverse-engineered the DWG format, and it’s now common for other CAD programs to read and sometimes write DWG files directly, with greater or lesser accuracy. Because the DWG format is complicated, isn’t documented, and gets changed every couple of years, no one ever figures it out perfectly. Thus, exchanging DWG files with non-Autodesk programs always involves some compatibility risks.
Warning When you send DWG files to other people — whether they use AutoCAD or a different CAD program — you need to make sure that their software can read the DWG file version that you’re sending. See Chapter 1 for information about AutoCAD DWG file versions.
Remember When you send DWG files to other people, remember to use the ETRANSMIT command to ensure that you send all of the dependent files (fonts, xrefs, and raster images). See Chapter 15 for details.

DXF (Drawing eXchange Format) is the Autodesk-approved format for exchanging between different CAD programs. (Some other vector graphics applications, such as drawing and illustration programs, read and write DXF files, too.) DXF is a documented version of the DWG format. Because DXF more-or-less exactly mimics the DWG file’s contents, it’s (usually) a faithful representation of AutoCAD drawings.
How well DXF works for exchanging data depends largely on the other program that you’re exchanging with. Some CAD and vector graphics programs do a good job of reading and writing DXF files, while others don’t. In practice, geometry usually comes through well, but properties, formatting, and other nongeometrical information can be tricky. Test before you commit to a large-scale exchange, and always check the results.
To create DXF files, use the SAVEAS command (FileðSave As) and choose one of the three DXF versions in the Files of Type drop-down list. To open a DXF file, do the same with the OPEN command (FileðOpen).

As Chapter 15 describes, DWF is Autodesk’s special “lightweight” drawing format for posting drawings on the Web or sharing them with people who don’t have AutoCAD. Those people can use Autodesk’s free Express Viewer program to view and print DWF files (as well as DWG files) describes how to create and use DWF files.

There are lots of different vector and raster graphics file formats, but Microsoft has been pretty successful at making its WMF and BMP formats the lingua franca — or should that be lingua bill-a? — for exchanging graphical information in Windows.
WMF (Windows MetaFile) is a vector format, so it does a decent job of representing AutoCAD objects such as lines, arcs, and text.
To create a WMF file showing some or all of the objects in a drawing, use the EXPORT command (FileðExport) and choose Metafile (*.wmf) in the Files of Type drop-down list. After you create a WMF file in AutoCAD, use the other program’s file insertion command to place the image in a document.
Tip AutoCAD puts objects in the WMF file with the colors and display lineweights that you see on the AutoCAD screen. To create a WMF file that looks like a monochrome plot — that is, with varying lineweights and all objects black — you need to set layer and object properties in AutoCAD so the objects look that way on-screen before you create the WMF file.
You can go the other direction, from a WMF file into AutoCAD, by using the WMFIN command (InsertðWindows Metafile).

BMP (BitMaP) is the standard Windows raster format. AutoCAD can create BMP files from drawing objects (via the EXPORT command) and place BMP files in drawings (via the IMage command). When you export AutoCAD drawing objects to a BMP file, all the objects get converted to dots. Turning a line into a bunch of dots isn’t a swell idea if you want to change the line again. But it is useful if you need to copy a drawing into a company brochure.
Warning
One problem with BMP files is their big file size. Unlike some other raster formats, BMP doesn’t offer compression. Because CAD drawings usually are fairly large in area, they can turn into monstrously large BMP files.
Creating a BMP file showing some or all of the objects in a drawing is just like creating a WMF file: Use the EXPORT command (FileðExport) but choose Bitmap (*.bmp) in the Files of Type drop-down list. After you create a BMP file in AutoCAD, you use the other program’s FileðOpen to open it or the graphics file insertion command to place it in an existing document.
If you want to go the other direction, a BMP file into an AutoCAD drawing, use the IMage command, as described in Chapter 13.

If you need to transfer lots of WMF or BMP figures, you can do it a bit more quickly with the Windows Clipboard, which bypasses the creation of WMF and BMP files on disk. Instead, Windows uses your computer’s memory to transfer the data. Choose EditðCopy in the program from which you want to copy the data and EditðPaste Special in the program to which you want to copy it. In the Paste Special dialog box, choose Picture to paste the image in WMF format or Bitmap to paste it in BMP format.

Although BMP is a standard Windows format for exchanging raster data, it’s certainly not the preferred format of many programs. Other common raster formats include PCX, JPEG, and TIFF (the latter two appears as JPG and TIF in Windows). Among their other advantages, these formats offer image compression, which can reduce the size of raster files dramatically.
If the program that you’re trying to work with works best with other formats, or you want to avoid huge BMP files, you have a couple of options:
Create an AutoCAD-friendly format (such as WMF or BMP) and translate it to another graphics format using a translation program such as HiJaak (www.imsisoft.com) or VuePrint (www.hamrick.com).
New for 2004 AutoCAD 2004 includes new JPGOUT, PNGOUT, and TIFOUT commands for creating JPG, PNG, and TIF files in the same way that you export WMF and BMP files. Type the command name, press Enter, specify a raster file name, and select the objects to be included in the image file. These commands use the current drawing area background color as the background color for the image. If you want your image background to be white, make sure that the AutoCAD drawing area color is white when you run the command. (Choose ToolsðOptionsðDisplayðColors to change display colors.)
If you need to convert drawings to a raster format other than BMP or TIF, the second option is to use the AutoCAD Raster File Format driver. This driver enables you to “plot” to a file using one of nine raster formats, including PCX, JPEG, and TIFF. Before you can use the Raster File Format driver, you must create a new plotter configuration: Choose FileðPlotter Manager and then run the Add-A-Plotter wizard. After you create the Raster File Format driver configuration, you use the Plot dialog box as described in Chapter 12 to generate “plots” to raster files.
To go the other direction, raster image file into an AutoCAD drawing, use the IMage command, as described in Chapter 13.

Microsoft Windows includes a data transfer feature, Object Linking and Embedding (OLE). Microsoft touts OLE as a total data exchange solution.
Tip Pronounce OLE like the Spanish cheer, not the Cockney way of saying hole.
If you want to share data between two OLE-aware programs (such as most Windows applications), creating an embedded or linked document shouldn’t be much more complicated than cut and paste. That’s the theory.
Here’s how it works. In OLE lingo, the program that you’re taking the data from is the source. The program that receives the data is called the container. For example, if you want to place a spreadsheet table from Excel into an AutoCAD drawing, Excel is the source, and AutoCAD is the container.

Warning Why not just shout, “OLE!”?
Unfortunately, OLE is afflicted with practical problems.
Compound OLE documents can slow performance — a lot. If you experiment with OLE, you need a fast computer with lots of memory — or lots of time on your hands.
Supporting OLE well is a difficult programming job, and many applications — including AutoCAD — suffer from OLE design limitations and bugs.
Getting consistent hard-copy output can be tricky, especially when you plot from AutoCAD. OLE objects that look fine on-screen often undergo amazingly creative but not necessarily desirable transformations when they come out on paper.
The potential benefits of using OLE with AutoCAD just aren’t worth all the pitfalls and limitations. Use the alternative methods described in this chapter, and save OLE for your next trip to Spain.
In Excel, you select the range of spreadsheet cells that you want to put in the AutoCAD drawing and choose EditðCopy to copy them to the Windows Clipboard. Then, you switch to AutoCAD and choose EditðPaste Special. The Paste Special choice displays a dialog box containing the choices Paste and Paste Link. The Paste option creates a copy of the object from the source document and embeds the copied object into the container document. The Paste Link option links the new object in the container document to its source document so any changes to the source document are automatically reflected in the container document. In other words, if you link a spreadsheet object to an AutoCAD drawing, changes that you make later in the Excel spreadsheet get propagated to the AutoCAD drawing automatically. If you embed the same spreadsheet object in an AutoCAD drawing, changes that you later make to the data in Excel aren’t reflected in the AutoCAD drawing.
That’s how it’s supposed to work. In practice, the container application sometimes doesn’t display or print all of the linked or embedded data correctly. See the “Why not just shout, ‘OLE!’?” sidebar for details.

If your goal is to show the entire AutoCAD program window, not just the drawing contained in it, create a screen capture. Most of the figures in this book are screen captures. You might use similar figures to put together a training manual or to show your mom all the cool software you use.
Windows includes a no-frills screen capture capability that is okay for an occasional screen capture. It works like this:
Capture the whole screen or active window with one of these steps:
Press the Print Screen key to capture the entire Windows screen, including the desktop and taskbar.
Hold down the Alt key and press the Print Screen key to capture just the active program window (for example, AutoCAD).
Windows copies a bitmap image to the Windows Clipboard.
Paste the bitmap image into another program. You have two options:
Paste into a paint program (such as the Paint program in Windows). Use that program to save a raster image as a BMP file format.
Paste the bitmap image directly into a document (such as a Word document or an AutoCAD drawing) without creating another file.
If you do lots of captures, a screen capture utility program makes the job faster and gives you more options. You can control the area of the screen that gets captured, save to different raster file formats with different monochrome, grayscale, and color options, and print screen captures. One good screen capture utility program is FullShot by Inbit, Inc. (www.inbit.com).
When you create screen captures, pay attention to resolution and colors:
High screen resolutions (for example, above 1280 x 1024) can make your captures unreadable when they get compressed onto an 81⁄2-x-11-inch sheet of paper and printed on a low-resolution printer.
Some colors don’t print in monochrome, and a black AutoCAD drawing area is overwhelmingly dark. For most of the screen captures in this book I used 1024 x 768 resolution, a white AutoCAD drawing area, and dark colors — mostly black — for all the objects in the drawing.

TXT (Text, also called ASCII for American Standard Code for Information Interchange) is the simplest format for storing letters and numbers. TXT files store only basic text, without such formatting as boldface or special paragraph characteristics. RTF (Rich Text Format) is a format developed by Microsoft for exchanging word processing documents (text plus formatting).
Select Import Text from the Multiline Text Editor window’s right-click menu to import an TXT or RTF file. AutoCAD imports plain text from TXT and RTF files, if you don’t use fancy formatting and aren’t fussy about aligning words and characters. Chapter 9 covers the Multiline Text Editor window.
Because no sane person would use AutoCAD as a word processor, AutoCAD doesn’t provide any special tools for exporting text. You can select AutoCAD text, copy it to the Windows Clipboard, then paste it into another program

Overview
It’s amazing to think that AutoCAD came into being two decades ago, at a time when most people thought that personal computers weren’t capable of a lot. It’s almost as amazing that, 20 years after its birth, AutoCAD remains the king of the microcomputer CAD hill by a tall margin. Many competing CAD programs have come to challenge AutoCAD, many have fallen, and a few are still around. Rumblings are circulating that the long-term future of CAD may belong to special-purpose, 3D-based software such as the Autodesk Inventor and Revit programs. Whether or not those rumblings amplify into a roar remains to be seen, but for the present and the near future anyway, AutoCAD is where the CAD action is.
In its evolution, AutoCAD has grown more complex, in part to keep up with the increasing complexity of the design and drafting processes that AutoCAD is intended to serve. It’s not enough just to draw nice-looking lines anymore. If you want to play CAD with the big boys and girls, you need to organize the objects you draw, their properties, and the files in which they reside in appropriate ways. You need to coordinate your CAD work with other people in your office who will be working on or making use of the same drawings. You need to be savvy about shipping drawings around via the Internet.
AutoCAD 2004 provides the tools for doing all these things, but it’s not always easy to figure out which hammer to pick up or which nail to bang on first. With this book, you have an excellent chance of creating a presentable, usable, printable, and sharable drawing on your first or second try without putting a T-square through your computer screen in frustration.