Zooming and panning
Naming and restoring views
Zooming and panning in paper space layouts
Regenerating the display
One of the advantages that has over manual drawing is AutoCAD's capability to give you different ways to view your drawing. You can zoom in close, zoom out to a great distance, and pan around. In fact, not only can you zoom and pan in your drawing, but in most kinds of drawings, you must do it frequently to be able to draw, edit, and view effectively.
Technical drawings are jam-packed with lines, text, and dimensions. Zooming and panning frequently enables you to see the details better, draw more confidently (because you can see what you're doing), and edit more quickly (because object selection is easier when there aren't a zillion objects on the screen). This chapter covers AutoCAD's most useful display control features.
Moving your viewpoint in to get a closer view of your drawing data is called zooming in; moving your viewpoint back to get a more expansive view is called zooming out. Moving your viewpoint to another part of your drawing without zooming in or out is called panning.
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. Early versions of AutoCAD included a sample drawing of our solar system, drawn to scale with kilometers as units, that proved this. If you zoomed all the way out, you could see Pluto's orbit, and you could zoom in close enough to Earth's moon to read the inscription on the plaque left by the Apollo 11 astronauts!
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 realtime panning. And in case you're wondering what realtime panning might be (as opposed to pretendtime panning, maybe?), it simply means you can see the objects moving around the screen as you drag the mouse up and down or back and forth. (Of course, it's your viewpoint that's moving, not the objects!)
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.
You'll get a better sense of panning and zooming around a drawing if you actually have a drawing to look at. Draw some objects on the screen, open one of your own existing drawings, or open one of AutoCAD's sample drawings located in the C:Program FilesAutoCAD 2009Sample folder. (If you're using AutoCAD LT, the sample drawings are located in the C:Program FilesAutoCAD LT 2009Sample folder.)
Note
Command access has shifted around quite a bit in AutoCAD 2009, and the impact naturally shows up most in the most frequently used commands — like PAN and ZOOM. Both PAN and the standard ZOOM command now have status bar buttons in both the 2D Drafting & Annotation and AutoCAD Classic workspaces. In addition, the Utilities panel in the Ribbon contains a Pan button and a flyout set of Zoom tool buttons. (AutoCAD Classic users will find these tool buttons on the Standard toolbar.)
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:
The command line version of the ZOOM command starts, and AutoCAD prompts:
Specify corner of window, enter a scale factor (nX or nXP), or [All/Center/Dynamic/Extents/Previous/Scale/Win dow/Object] <real time>:Press Enter to accept Realtime, the default option.
The Realtime option of the ZOOM command starts. The crosshairs change 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.Move the magnifying glass cursor near the middle of the screen, press and hold down the left mouse button, and drag the cursor up and down until the objects you want to see almost fill the screen.
Dragging up increases the zoom magnification, and dragging down decreases it.
Right-click in the drawing area and choose Pan from the menu that appears (shown in Figure 12-1).
Since AutoCAD LT doesn't do 3D, there's no 3D Orbit choice on LT's right-click menu. The magnifying glass cursor changes to a hand.
Click and drag to pan the drawing in any direction.
Tip
You can use the right-click menu to toggle between Zoom and Pan as many times as you like. If you get lost in your drawing, choose Zoom Original or Zoom Extents to return to a more familiar view.
Right-click in the drawing area and choose Exit.
The Zoom or Pan Realtime cursor returns to the normal AutoCAD crosshairs.
Tip
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 and backward.
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.
Note
The scroll wheel or middle mouse button zoom and pan operations described in the preceding list depend on an obscure AutoCAD system variable named MBUTTONPAN. 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 list. Unless your system has been customized by someone, if you change MBUTTONPAN to 0, clicking the middle mouse button displays an object snap menu at the crosshairs, 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+right-click to display the object snap menu at the crosshairs.)
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.
Tip
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 scroll bars on the borders of the drawing window to scroll, or pan, a step at a time; or click and drag the little scroll boxes to pan as little or as much as you want to. By default, scroll bars are turned on in both AutoCAD and AutoCAD LT. To turn them off or on, choose Tools
Realtime zooming is good as far as it goes, but you get much more control over the display if you use some of ZOOM's alternative methods. Because zooming is such a frequent activity in AutoCAD, it's worth knowing some of those alternative ways of doing it.
Note
In the new Ribbon-based workspaces, you'll find tool buttons for all the following ZOOM options on the Home tab's Utilities panel. The magnifying-glass button has a menu — click the down arrow beside the magnifying glass, and a menu with the other options opens (see Figure 12-2). There is also a ZOOM button on the status bar; it doesn't present options but instead runs the command-line version of ZOOM.
In the AutoCAD Classic workspace, Zoom Realtime and Zoom Previous have full-time tool buttons on the Standard toolbar. The middle of the three magnifying-glass buttons is a flyout button. Click and hold on it, and buttons for the other Zoom options fly out. Keep holding the mouse button and drag down the tool buttons; then release the mouse button over the Zoom option you want.
In both Ribbon-based and classic workspaces, the most recently used ZOOM option floats to the top of the pile, because, theoretically, you may want to use that option again soon.
The ZOOM command has several different options, the most important of which are the following:
Tip
It's a good idea to Zoom All or Zoom Extents and then save the drawing before you close it. 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 as soon as they start working.
If you've accidentally copied some objects way beyond where they should be, Zoom All or Extents will make them show up so you can delete them.
The drawing preview that appears in the Select File dialog box displays the full drawing, instead of just a tiny, unidentifiable corner of it.
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.
Tip
AutoCAD provides smooth view transitions whenever you use the non-realtime pan and zoom commands. Sometimes you can get lost if you do a ZOOM All from a small, highly magnified area. It's a bad idea to leave a trail of breadcrumbs across your screen, so these slow-motion pans and zooms may be fine, at least until you do know your way out of the forest ...or your drawing. If, like me, you find that this feature gets old fast, there's a View Transitions dialog box (type VTOPTIONS to open it) in which you can turn it off. Just uncheck the Enable Animation for Pan & Zoom option.
Tip
Some of the zoom options take some getting used to. I recommend that you use realtime zoom and pan for most of your zooming and panning. Supplement it with Zoom Window to move quickly into a precise area, Zoom Previous to back up in zoom/pan time, and Zoom All or Zoom Extents to view your whole drawing.
AutoCAD's ZOOM and PAN partnership have been around since the get-go, and little has changed — apart from the addition of realtime panning and zooming several releases back — in the basics of navigating around in the drawing. Until now, that is!
Note
AutoCAD 2009 adds a couple of new viewing devices. (They're much too sophisticated to refer to as simple commands!) One of them (the Navigation Cube) works exclusively in 3D, and the other (the SteeringWheel) has a 2D configuration that's much less useful than the regular PAN and ZOOM commands. The limited space I have precludes my covering AutoCAD's 3D features. If you want to learn about 3D in general, or the new viewing commands in particular, the best place to start is the User Guide in the online help system. For modeling, check out Work with 3D Models, and for viewing AutoCAD 3D models, see Control the Drawing Views
If you find yourself repeatedly zooming and panning to the same area, you can probably get there faster with a named view. After you name and save a view of a particular area of your drawing, you can return to that area quickly by restoring the view. You use the VIEW command, which displays the View Manager dialog box, to create and restore named views.
Note
The View Manager's tasks have increased in AutoCAD 2009. (Managers never do enough work anyway, right?) The View Manager now manages shots as well as views. Views have been a part of AutoCAD from very early days, but shots are new in this version. Where views are static, shots are motion based. (You may have noticed the ShowMotion button on the status bar.) And not only can you create animated scenes, you can even add fancy transitions like jump cuts and fades. However, because this kind of production is associated with 3D, and because I don't cover 3D in this book, you should visit the online help — especially the New Features Workshop — for more on shots and showing motion. Follow these steps to create a named view:
Zoom and pan until you find the area of the drawing that you want to assign a name to.
Choose View
The View Manager dialog box appears.
Click the New button.
The New View / Shot Properties dialog box appears, as shown in Figure 12-3.
Type a name in the View Name text box.
(Optional) Type a new category in the View Category box or select an existing one from the drop-down list.
You create your own View Categories to organize views and certain display characteristics of views. This is mainly used in sheet sets. If you aren't using the sheet sets feature, you can leave this box blank.
Make sure the View Type drop-down is set to Still.
Visit the New Features Workshop and the online help if you'd like to know more about the Cinematic and Recorded Walk options.
Note
AutoCAD LT doesn't support view categories. The New View dialog box in LT is missing the View Category list box and the Background area shown in Figure 12-3.
In the Boundary area, select the Current Display radio button, if it's not selected already.
Tip
If you want to save a different view boundary, select the Define Window radio button instead, click the Define View Window button to the right of it, and pick two corners of the region's boundary (as if you were zooming windows).
Confirm or change the choices in the Settings area.
If you select the Save Layer Snapshot with View check box, when you later restore the view, AutoCAD also will restore the layer visibility settings (on/off and freeze/thaw) that were in effect when you created the view. (Chapter 6 describes the layer visibility settings.) The UCS, Live Section, and Visual Style settings are primarily for 3D drawings; the latter two settings are not included in AutoCAD LT.
Click OK.
The New View dialog box disappears, and you see your new named view in the list in the View Manager dialog box.
Click OK.
The View Manager dialog box disappears.
To restore a named view, choose View
Tip
You also can plot the area defined by a named view. See Chapter 16 for instructions on plotting views.
All the zoom, pan, and view operations I describe in this chapter work in paper space layouts as well as in model space. (Chapters 4 and 5 describe the differences between model space and paper space and how to navigate between the two.) One little complication exists, though: In a paper space layout — that is, any drawing area tab except for the Model tab — it's possible for the crosshairs to be in either paper space or in model space inside a viewport. Zooming and panning have a different effect depending on which space your crosshairs are in at the moment. You switch between the two spaces using the MSPACE (alias MS) and PSPACE (PS) commands.
Experiment with the different effects by following these steps:
Open a drawing that contains at least one paper space layout with a title block and one or more viewports.
If you don't have any such drawings handy, try using the AutoCAD sample drawing located at
C:Program FilesAutoCAD 2009SampleSheet SetsArchitecturalA-05.dwg. AutoCAD LT users can tryC:Program FilesAutoCAD LT 2009SampleTallship.dwg.Click Quick View Layouts on the status bar, then click one of the layout preview images — that is, any image other than the Model preview image.
AutoCAD displays the paper space layout, including any title block and viewports. Click somewhere away from an image to dismiss the Quick View image bar.
Type PSPACE (or its alias PS ) and press Enter.
AutoCAD will either switch to paper space or tell you that you're already there.
Tip
Alternatively, you can double-click in the gray part of the drawing area outside the layout.
You should see the triangular paper space UCS icon at the lower-left corner of the display. If you don't see an icon, click the View tab on the Ribbon, then open the UCS panel's slideout and click Display UCS Icon. (On the classic menu bar, choose View
Type Z, press Enter, then type A, then press Enter.
AutoCAD displays the entire layout, as shown in Figure 12-4.
Zoom and pan by using any of the techniques described in this chapter.
Zooming and panning change the appearance of the title block, as shown in Figure 12-5. The effect is similar to moving a plotted sheet in and out and all around in front of your face.
Return to a zoomed-all view using any of these techniques, or type Z and press Enter, then type A and press Enter.
AutoCAD displays the entire layout again.
Type MSPACE (or MS ) and press Enter.
Alternatively, you can double-click with the crosshairs over a viewport.
You should see the model space UCS icon at the lower-left corner of the display (refer to Step 3 if you don't see an icon). The crosshairs are now in model space, inside the viewport, so zooming and panning change only the display of the objects that are visible in the viewport. The display of the title block doesn't change.
Zoom and pan using any of the techniques described in this chapter.
Zooming and panning don't change the appearance of the title block, as shown in Figure 12-6. The result looks as if you're moving a picture of the model space geometry in and out and all around behind a frame.
Note
In real drawings, you usually shouldn't zoom and pan inside viewports after they've been set up (see Chapter 5). Doing so changes the scale of the viewport, which messes up plotting. I'm asking you to do it here to illustrate the difference between zooming in paper space and zooming in a model space viewport.
If the title block changes when you zoom and pan, someone has locked the viewport to prevent the kind of mischief that I warn against in the previous paragraph. (You also see the command prompt
Viewport is view-locked. Switching to Paper space.) Refer to Chapter 5 for information on locking and unlocking viewports.Choose Zoom Previous from the Utilities panel's Zoom drop-down list (or choose View
Type PS and press Enter.
Always leave the crosshairs in paper space when you're ready to call a drawing finished.
Click the Close window control in the upper-right corner of the drawing area (2D Drafting & Annotation workspace) or click Close on the drawing title bar (AutoCAD Classic). Click No to close the drawing without saving changes.
In this example, I have you close the drawing without saving changes just in case you did mess up the viewport zoom scale.
In most cases, you set up a paper space layout once, as described in Chapter 5, and then just return to it to plot. You shouldn't be spending a lot of time zooming and panning in paper space layouts. You zoom and pan to get a better view of what you're drawing and editing, and that's what full-screen model space is for. But if you do want to zoom in paper space — to get a better look at part of your title block, for example — make sure that you're doing it with the triangular paper space UCS icon on display at the lower-left corner of the drawing area.
Tip
The VPMAX and VPMIN commands allow you to maximize and minimize a viewport in the current layout. These commands provide an alternative to switching between the Model and Layout buttons without the potential problems of zooming inside of paper space viewports. The easiest way to run VPMAX or VPMIN is to click the Maximize Viewport/Minimize Viewport button located on the status bar, to the right of the Model and Layout buttons.
Note
As you zoom and pan around your drawing, you may wonder how the image that you see on-screen is related to the DWG file that AutoCAD saves on the hard disk. Well, maybe you don't wonder about that, but I'm going to tell you anyway!
When you draw and edit objects, AutoCAD stores all their geometrical properties (that is, location and size) in a highly precise form — technically, double floating-point precision. The program always maintains that precision when you save the DWG file. For computer performance reasons, however, AutoCAD does not use that high-precision form of the data to display your drawing on-screen. Instead, AutoCAD converts the highly precise numbers in the DWG file into slightly less precise integers in order to create the view that you see on-screen.
The happy consequence of this conversion is that zooming, panning, and other display changes are a lot faster than they would be otherwise. The unhappy consequence is that the conversion, which is called a regeneration (or regen for short), occasionally leaves you with some artifacts to deal with.
In most cases, AutoCAD performs regenerations automatically when it needs to. You will sometimes see command line messages like Regenerating model or Regenerating layout, which indicate that AutoCAD is taking care of regens for you.
If, on the other hand, you see the command line message Regen queued, AutoCAD is warning you that it's not performing a regeneration, even though one might be advisable now. In addition, you might see a warning dialog box with the message About to regen -- proceed? These messages are AutoCAD's way of saying, "What your drawing looks like on the screen at the moment may not exactly match the real version of the drawing database that gets stored when you save the drawing. I'll update the display version at the next regeneration." You can control whether regenerations happen automatically with the REGENMODE system variable — refer to Chapter 22 for more information on this variable and system variables in general.
Warning
Don't confuse the REGEN command with the REDRAW command. REGEN (View
Tip
The REGENALL command (View