AutoCAD 2005 for Dummies

moving your viewpoint back to get a more expansive view is called zooming out.

Zooming in and out of your drawing is one of the big advantages that AutoCAD offers over manual drawing. You can do detailed work on tiny objects and then zoom out and move around rooms, houses, or neighborhoods from an Olympian perspective.

Panning is closely related to zooming. If you zoom in enough that some of your drawing no longer shows up on-screen, you’re going to want to pan around — move left, right, up, and down in your drawing — without zooming in and out. AutoCAD makes panning easy with scroll bars and real-time panning.

Both panning and zooming change what is known as the view. The view is the current location and magnification of the AutoCAD depiction of your drawing. Each time you zoom or pan, you establish a new view. You can give a name to a specific view to make returning to that view easy, as I demonstrate later in this chapter.

Fortunately, zooming and panning in AutoCAD is as simple as it is necessary. The following steps describe how to use AutoCAD’s Zoom and Pan Realtime feature, which is easy to operate and provides a lot of flexibility:

1. Click the Zoom Realtime button (the one that looks a magnifying glass with a plus/minus sign next to it) on the Standard toolbar.

The Realtime option of the Zoom command starts. The cursor changes to a magnifying glass, and AutoCAD prompts you at the command line:

Press ESC or ENTER to exit, or right-click to display shortcut menu.

2. Move the cursor near the middle of the screen, press and hold down the left mouse button, and drag the cursor up and down until the table almost fills the screen.

Dragging up increases the zoom magnification and dragging down decreases it. 

3. Right-click in the drawing area to display the Zoom/Pan Realtime cursor menu, shown in Figure 7-1, and choose Pan from the menu that appears.

Figure 7-1: The Zoom/Pan Realtime cursor menu.

The cursor changes to a hand. 

4. Click and drag to pan the drawing in any direction.

  You can use the right-click menu to toggle back and forth between Zoom and Pan as many times as you like. If you get lost, choose Zoom Original or Zoom Extents to return to a recognizable view.

5. Right-click in the drawing area and choose Exit.

The cursor returns to the normal AutoCAD crosshairs.

In the preceding example, you started with zooming and ended with panning. You also have the option of doing the reverse: Click the Pan Realtime button (the one showing a hand), and after you’ve panned, use the right- click menu to switch to zooming. However you start it, the important thing to realize is that Zoom and Pan Realtime is a single AutoCAD function. At any time, you can switch between panning and zooming (or switch to a related function, such as Zoom Window) by using the right-click menu.

  You also can pan and zoom by using your mouse’s scroll wheel (if it has one) or the middle button of a three-button mouse:

? To zoom in and out, roll the scroll wheel forward (in) or backward (out).

? To zoom to the extents of your drawing, double-click the scroll wheel or the middle button.

? To pan, hold down the scroll wheel or the middle button as you move the mouse.

  The scroll wheel or middle mouse button zoom and pan operations described in the preceding paragraph depend on an obscure AutoCAD system variable named MBUTTONPAN. (See Chapter 2 for a description of what system variables are and how to change them.) When MBUTTONPAN is set to 1 — the default value — you can use the middle button to pan and zoom, as I describe in the preceding tip. If you change MBUTTONPAN to 0, clicking the middle mouse button displays a cursor object snap menu, as it did in older AutoCAD versions. If you’re not able to zoom or pan with your middle mouse button, set MBUTTONPAN back to 1. (With MBUTTONPAN set to 1, you use Shift+rightclick to display the cursor object snap menu.)

Realtime zooming and panning is the easiest, most interactive way to get around in your drawings. In some situations, though, this method is less efficient or precise than the old-fashioned methods, the most important of which are described in the next section.

Out of the frying pan…

Another way to pan in AutoCAD should be familiar from other Windows programs — the scroll bars in the drawing area. Scrolling is the same in AutoCAD as in any other Windows program; click the arrows in the right and bottom borders of the drawing window to scroll, or pan, a step at a time; or click and drag the little square “thumbs” in those borders to pan as little or as much as you want to.

  Believe it or not, the realtime and scrollbar panning methods are relatively recent enhancements in AutoCAD’s long history. These methods have pretty much replaced the less-intuitive two- point method of panning in older versions of AutoCAD. If you want to see how Grandpa used to pan, enter –Pan (with the leading dash) at the command line and then follow the prompts. This older method remains useful in special situations where you need to pan orthogonally by a specific distance — that is, move the display precisely horizontally without wavering up and down or precisely vertically without wavering side to side. This situation sometimes occurs in advanced paper space viewport setup, which I don’t cover in this book.

Time to zoom

Because zooming is such a frequent necessity in AutoCAD, it’s worth knowing some alternative ways of doing it.

The Zoom command has different options, the most important of which are the following:

? All and Extents: Zoom Extents zooms out just far enough to show all the objects in the current drawing. Zoom All does the same thing, unless the drawings limits are larger than the extents, in which case Zoom All zooms to show the entire rectangular area defined by the limits. If you’ve defined your limits properly (see Chapter 3), Zoom All is a good way to see your whole drawing area. These two options are especially useful when you zoom in too small or pan off into empty space and want to see your entire drawing again.

  It’s a good idea to Zoom All or Zoom Extents and then save before you close a drawing. By performing these steps, you ensure the following:

 • The next person who opens the drawing — whether it’s you or someone else — can see the full drawing from the very beginning.

 • The drawing preview that displays in the Select File dialog box displays the full drawing, instead of just a tiny, unidentifiable corner of it.

? Window: This option is great for zooming in quickly and precisely. It zooms to a section of your drawing that you specify by clicking two points. The two points define the diagonal of a window around the area you want to look at. (Note that the Zoom command’s Window option is not a click-and-drag operation — unlike in some other Windows programs and, confusingly, unlike in the Zoom/Pan realtime Zoom Window option. With the Zoom command’s Window option, you click one corner, release the mouse button, and then click the other corner.)

? Scale (X/XP): The X option zooms by a percentage of the current display; values less than 1 cause you to zoom in, values greater than 1 cause you to zoom out. You can also think of the value as a scaling factor: 0.5X causes the screen image to shrink to half its apparent size, and 2X causes the screen image to double its apparent size. (The XP option after a number is for zooming model space objects in a viewport relative to paper space; see Chapter 3 for information about paper space.)

? Realtime: Realtime zooming, the technique described previously, enables you to zoom in and out by starting a realtime zoom and then moving the cursor up to zoom in or down to zoom out.

? Previous: This option undoes the last zoom and/or pan sequence. It’s like going back in time but without the funny costumes!