Chapter One
Starting to Draw IN THIS CHAPTER
Getting acquainted with AutoCAD and AutoCAD LT
Starting AutoCAD and AutoCAD LT
Creating a new drawing
Using the AutoCAD and AutoCAD LT interface
Saving your drawing
Closing a drawing and exiting AutoCAD and AutoCAD LT
In this chapter, I explain the essentials that you need to start drawings. After a little background, I discuss the basics of the screen that you see when you open AutoCAD or AutoCAD LT, and how to use it. If you''ve never used AutoCAD before, do the "Quick Start: Drawing a Window" chapter first.
AutoCAD and its younger brother, AutoCAD LT, are both created by Autodesk. Together they are the most widely used technical drawing programs anywhere. AutoCAD alone has more than 6,000,000 registered users. According to Autodesk, CAD stands for computer-aided design, but it can also stand for computer-aided drafting or drawing.
The first version of AutoCAD, running under DOS, came out in 1982. AutoCAD was the first significant CAD program to run on a desktop computer. At the time, most other technical drawing programs ran on high-end workstations or even mainframes. AutoCAD LT was introduced in 1993, as a less expensive alternative to AutoCAD, for people who don''t need all of AutoCAD''s advanced features.
AutoCAD''s Advantages
AutoCAD''s success has been attributed to its famous open architecture - the flexibility that the end user has to customize the program by using source code files in plain text (ASCII) format - and programming languages (such as AutoLISP, VB.NET and C#).
As a result, AutoCAD is an extremely flexible drafting program, applicable to all fields. AutoCAD''s support for languages other than English, including those using other alphabets, is unparalleled, making AutoCAD highly popular abroad. As a result, AutoCAD is used in all disciplines and in more than 150 countries.
Through a high level of technical innovation and expertise, Autodesk has created a program with advanced features and capabilities, including 3D surface and solid modeling and visualization, access to external databases, intelligent dimensioning, importing and exporting of other file formats, Internet support, and much more.
Part I AutoCAD and AutoCAD LT Basics
The major disciplines that use AutoCAD are:
* Architectural, Engineering, and Construction (AEC)
* Mechanical
* Geographic Information Systems (GIS)
* Surveying and Civil Engineering
* Facilities Management
* Electrical/electronic
* Multimedia
However, AutoCAD has many other lesser-known uses, such as pattern making in the garment industry, sign making, and so on. In this book, I provide examples from several fields. The world of AutoCAD is very broad, and you can learn from seeing the many approaches that AutoCAD makes possible.
Comparing AutoCAD and AutoCAD LT
AutoCAD LT''s advantages are its lower cost and its compatibility with AutoCAD. The programming code that is used to create AutoCAD LT is a subset of the code used in AutoCAD. Here are the major differences between AutoCAD and AutoCAD LT:
* AutoCAD includes features that enable CAD managers to hold drawings to certain standards, such as for layer names and text styles. AutoCAD LT doesn''t contain these features.
* AutoCAD LT is not as customizable as AutoCAD, which is both programmable and fully customizable. It also doesn''t include the Action Recorder.
* AutoCAD LT includes minimal options for 3D; AutoCAD includes a full-featured 3D capability. * AutoCAD LT has fewer presentation features than AutoCAD, which includes gradient fills and 3D rendering.
* AutoCAD LT is deployable on a network but does not have AutoCAD''s network license management feature that includes reporting and flexible licensing.
* AutoCAD LT does not offer the database connectivity feature, but you can use tables to connect to data in a Microsoft Office Excel file; AutoCAD offers the flexibility to connect to other types of databases, create labels from the data, and so on.
* AutoCAD LT does not include AutoCAD''s quick-dimensioning feature, which allows you to quickly insert a number of dimensions, one after the other.
* AutoCAD LT does not come with Express Tools, a set of additional routines that ship with AutoCAD.
* AutoCAD LT does not include parametric constraints, which allow you to constrain the relationships among objects but you can use the parametric constraints that are in a drawing that was created with AutoCAD.
* AutoCAD LT does not include the sheet set feature, which was introduced in AutoCAD 2005.
AutoCAD and AutoCAD LT have a few other minor differences, as well. Some of these differences are only in the user interface, so you can accomplish the same task but the procedure is slightly different.
Starting AutoCAD and AutoCAD LT
This section starts a quick tour of AutoCAD and AutoCAD LT. The first step is to start the program.
ON the DVD-ROMON the DVD-ROM
The DVD contains a 30-day trial version of AutoCAD 2010 and AutoCAD LT 2010.
This book covers AutoCAD 2010 and AutoCAD LT 2010 running on Windows XP Home/Professional, or Windows Vista. (The figures were taken in Windows Vista.) Every computer is set up somewhat differently, so you may need to adjust the following steps slightly. If you didn''t install the software yourself and are unfamiliar with the folders (also called directories) on your computer, get help from someone who is familiar with your computer system.
CROSS-REF
If you need information on installing AutoCAD or AutoCAD LT, see Appendix A. Appendix A also covers configuring the software and printers or plotters.
By default, installing AutoCAD or AutoCAD LT places a shortcut on your desktop. You can double-click one of the shortcuts to launch the program that is installed on your machine, or use the Start menu to choose one of the following:
* For AutoCAD: Start-> (All) Programs-> Autodesk-> AutoCAD 2010-> AutoCAD 2010
* For AutoCAD LT: Start-> (All) Programs-> Autodesk-> AutoCAD LT 2010-> AutoCAD LT 2010
Creating a New Drawing
After you launch AutoCAD or AutoCAD LT, it automatically opens a new drawing named Drawing1.dwg. You can see the drawing name on the title bar. You can start drawing immediately. In Chapter 2, I explain how to start a drawing based on a template and how to open an existing drawing.
STEPS: Starting AutoCAD or AutoCAD LT
1. Click Start on the Windows task bar at the bottom of your screen.
2. Choose one of the following: * For AutoCAD. Start-> (All) Programs-> Autodesk-> AutoCAD 2010-> AutoCAD 2010
* For AutoCAD LT. Start-> (All) Programs-> Autodesk-> AutoCAD LT 2010-> AutoCAD LT 2010
You see a blank drawing named Drawing1.dwg.
If you are continuing with this chapter, keep this drawing open. I cover exiting from AutoCAD and AutoCAD LT later in this chapter.
Using the AutoCAD and AutoCAD LT Interface
AutoCAD offers three quite different preset workspaces, depending on how you want to work. For example, these workspaces determine the ribbon components, toolbars, and other interface items that you see. AutoCAD offers both 2D and 3D environments. AutoCAD LT has only 2D environments, and the AutoCAD 2D and the AutoCAD LT environments are similar. In this section, I discuss the 2D environment. Both AutoCAD and AutoCAD LT offer two 2D workspaces: 2D Drafting & Annotation and AutoCAD (or
AutoCAD LT) Classic. The 2D Drafting & Annotation workspace is the default workspace and displays the ribbon for executing commands. The AutoCAD Classic and AutoCAD LT Classic workspaces display toolbars and a menu instead.
NOTE
AutoCAD''s 3D Modeling workspace creates a 3D environment including the drawing templates acad3D.dwt and acadiso3D.dwt. (I cover templates in Chapter 2.) I cover this 3D environment in Part IV, "Drawing in Three Dimensions."
Figure 1.1 shows the default screen that appears when you first open AutoCAD or AutoCAD LT. Your screen may look somewhat different - remember that AutoCAD and AutoCAD LT can be customized in many ways - but the general features will be the same. If you see other items open on your screen, you can close all these items by clicking their Close (X) button.
NOTE
The default screen color is off-white. You can leave it that way or change the drawing area color, as I explain in Appendix A.
If you find yourself in a 3D environment in AutoCAD, you''ll see a gray background and a perspective view. To work in 2D in AutoCAD, switch to a 2D environment, following these steps in AutoCAD:
1. From the Workspace Switching pop-up menu, choose 2D Drafting & Annotation. This displays the ribbon with 2D commands.
2. Choose Application Button-> New. From the Select Template dialog box, choose acad.dwt and click Open. This places you in a 2D view and turns off the grid.
The AutoCAD and AutoCAD LT screens consist of four important areas. These are discussed in the following sections.
The drawing area
The blank area in the middle of the screen, called the graphics window or drawing area, is where you draw. You can think of this as a sheet of drafting paper, except that this piece of paper can be any size - even the size of a huge factory or an entire county!
By default, you draw in model space, so called because that''s where you draw your models. When you create a new drawing, by default, you are in model space, so you can just start drawing. You can lay out your drawings for plotting in paper space, also called a layout. To switch from model space to a layout, you use the Layout tab at the bottom of the drawing area. You click the Model tab to switch back to model space. (See Chapter 17 for details.)
NOTE
Rather than the model and layout tabs, you may see Model and Layout1 buttons on the status bar. You can switch between the buttons and tabs by right-clicking either feature and choosing from the shortcut menu.
When you start to draw, you need to specify where to start drawing. One way is to use coordinates. To specify a coordinate, the universally accepted convention is to put the X coordinate first, followed by a comma, and then the Y coordinate. Examples are -3,5, 3,2, 6,-2, and -1,-1. These coordinates specify points in the drawing area.
CROSS-REF
Chapter 4 is devoted to explaining how to specify coordinates. To create three-dimensional models, you need to add a Z coordinate when specifying a point. Chapter 21 discusses three-dimensional coordinates.
TIP
If you want the maximum amount of free space for drawing, click the Clean Screen button at the right side of the status bar to remove the ribbon. Click the same button to get it back. You can also press Ctrl+0 to toggle between the two displays. You can double-click the active tab to cycle through three display states of the ribbon that collapse and expand the ribbon.
The UCS icon
Notice the symbol with two arrows in the drawing area in Figure 1.1. This symbol is called the User Coordinate System (UCS) icon. The arrows point to the positive directions of the X and Y axes to help you keep your bearings. (In a 3D environment, you see a Z axis as well.) You can change the look of this icon, and turn it on and off, as I explain in Chapter 8.
The crosshairs
In the drawing area of Figure 1.1, notice the intersecting lines with a small box at their intersection. The small box is called the pickbox because it helps you to select, or pick, objects. The lines are called crosshairs. They show you the location of the mouse cursor in relation to other objects in your drawing.
As you move your mouse around, the pickbox and crosshairs move with your mouse. At the bottom of your screen, at the left end of the status bar (described later), you can see the X,Y coordinates change as you move your mouse.
The ribbon and Quick Access toolbar
At the top of your screen is the title bar, and directly beneath the title bar is the ribbon. On the left side of the title bar is the Quick Access toolbar. The ribbon has tabs, and each tab is divided into control panels (usually called just panels), which are sections of related commands. I explain how to work with the ribbon and the Quick Access toolbar in Chapter 3.
NOTE
The AutoCAD Classic and AutoCAD LT Classic workspaces do not show the ribbon; instead, you see three toolbars (the Draw, Modify, and Draw Order toolbars), which are usually docked at the left and right sides of the screen. From the Workspace Switching pop-up list, try switching between the 2D Drafting & Annotation workspace and the AutoCAD or AutoCAD LT Classic workspace to see which one you prefer. In Appendix A, I explain how to customize workspaces.
On the Home tab, in the Draw panel of the ribbon, hover the mouse cursor over the leftmost button. You see a tooltip that says Line, as shown in Figure 1.2. Below the tooltip, a description tells you that this button creates straight-line segments. If you continue to hover the cursor over the Line button, the tooltip expands to provide more information about the command.
You use buttons on the ribbon to execute commands. For example, to draw a line, you click the Line button on the Draw panel of the ribbon''s Home tab. You get some practice drawing lines in the exercise that follows. (In the AutoCAD Classic or AutoCAD LT Classic workspace, you would click the Line button on the Draw toolbar to draw a line.)
NOTE
If you inadvertently start a command that you don''t want to use, press Esc.
The Quick Access toolbar contains a few often-used commands that are useful to have available all the time. Examples are commands to start a new drawing, open an existing drawing, and save a drawing.
Because you can customize the ribbon and the Quick Access toolbar to suit your needs, your screen may appear somewhat different. (See Chapter 29 for information on customizing the Quick Access toolbar, and see Chapter 33 for information on customizing the ribbon.) Remember that if the current workspace is AutoCAD Classic or AutoCAD LT Classic, you won''t see the ribbon or Quick Access toolbar; instead, you''ll see a menu bar at the top and several toolbars.
TIP
You can lock the position of ribbon panels (if they''re not docked), toolbars, and windows (palettes). On the right side of the status bar, at the bottom of the screen, is a Lock icon. Click this icon to open a menu allowing you to individually lock specific window, panel, or toolbar components. You can also choose the All option and lock or unlock everything. Locking these interface components prevents you from moving them inadvertently.
Using the Application menu
When you click the Application Button, a menu opens (the Application menu), giving you access to file-related commands, as shown in Figure 1.3.
NEW FEATURE
The Application menu is new for AutoCAD 2010 and AutoCAD LT 2010. It replaces the Menu Browser from AutoCAD 2009 and AutoCAD LT 2009. The full menu of previous releases is no longer there; instead, the menu contains commands related to files, a search box, a list of recent documents, access to other open drawings, and a link to the Options dialog box.
TIP
You can display the menu bar along with the ribbon. Type menubar on the command line, and then enter 1 . To hide the menu bar, enter 0 . Alternatively, you can click the down arrow at the right end of the Quick Access toolbar, and choose Show Menu Bar. Choose Hide Menu Bar to hide it.
When you open the Application menu, you can type a search term in the Search text box to find a command. On the right, you see a list of drawings that you opened recently. At the top of the list of drawings, you can click a drop-down arrow to choose to display them alphabetically (ordered list), by date, or by type. To the right, you can click a drop-down arrow to display the drawings as icons, or as small, medium, or large images. However, even if you display just icons, if you hover the cursor over any drawing name, an image of the drawing appears.
TIP
Click the Open Documents button to show open drawings rather than recently used drawings.
The Options button, at the bottom of the Application menu, opens the Options dialog box where you can specify many settings that affect how AutoCAD works. I explain the Options dialog box in detail in Appendix A.
The command line and dynamic input tooltip
At the bottom of the drawing area, you see a separate window showing approximately three lines of text. (You can change it to show as many lines as you like by dragging the top edge of the window up or down.) Notice the word Command:. This is the command line. You can execute any command by typing it on the command line.
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Excerpted from AutoCAD 2010 and AutoCAD LT 2010 Bibleby Ellen Finkelstein Copyright © 2009 by Ellen Finkelstein. Excerpted by permission.
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