AutoCAD For Dummies. Ralph Grabowski
Читать онлайн книгу.
Window options, respectively. These three command sequences, in combination with the wheel mouse, typically account for more than 99 percent of your panning and zooming needs. (I almost never use any Ribbon or navigation bar options.)
I cover another important Zoom option when discussing paper space viewports in Chapter 12.
A View by Any Other Name
If you repeatedly have to zoom or pan to the same area, you can quickly see what you want to see by using a named view. After you name and save a view of a particular area of a drawing, you can return to that area quickly by restoring the view with its name. You use the View command, which displays the View Manager dialog box, to create and restore named views.
Follow these steps to create a named view:
1 Zoom and Pan until you find the area of the drawing to which you want to assign a name.
2 Start the View command from the keyboard. Or on the View tab on the Ribbon, click View Manager in the Named Views panel.If the Named Views panel is not visible, right-click anywhere in the View tab, click Show Panels, and then click Views.The View Manager dialog box opens.
3 Click New.The New View/Shot Properties (New View in AutoCAD LT) dialog box appears, as shown in Figure 5-3.FIGURE 5-3: Save a view in the drawing.
4 Type a name in the View Name text box.
5 (Optional) Type a new category in the View Category text 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 feature is used mainly in sheet sets. If you aren’t using them, you can leave the default value, <None>, in the View Category box or clear the current value. (A discussion of sheet sets is beyond the scope of this book.)
6 Make sure that the View Type drop-down list is set to Still.The Still option creates a static thumbnail image of the objects in the area that is defined by the named view for use in ShowMotion. Visit the online Help system if you want to know more about the Cinematic and Recorded Walk options that you can choose from this drop-down menu, which are used mainly in 3D work.AutoCAD LT doesn’t support view types, so if you’re working with AutoCAD LT, skip Step 6. The New View dialog box in AutoCAD LT omits the View Type list box, most of the Settings drop-down options, and the Background area.
7 In the Boundary area, select the Current Display radio button, if it isn’t selected already. If instead you want to save a different view boundary, select the Define Window radio button, click the Define View Window button that appears to the right of it, and pick two corners of the region’s boundary (as though you’re zooming windows).
8 If you really want to get fancy, click the down arrow in the lower-left corner.A detailed description of all the options is beyond the scope of this book.
9 Confirm or change the choices.If you select the Save Layer Snapshot with View check box, when you later restore the view, AutoCAD also restores the layer visibility settings (On/Off and Freeze/Thaw) that were in effect when you created the view. I discuss layer visibility settings in Chapter 9. The Live Section and Visual Style settings are intended primarily for 3D drawings; these two settings aren't included in AutoCAD LT.
10 Click OK.The New View/Shot Properties (New View in AutoCAD LT) dialog box closes, and you see the new named view in the list in the View Manager dialog box.
11 Click OK.The View Manager dialog box closes.
To restore a named view, follow these steps:
1 From the View tab on the Ribbon, click View Manager from the View panel.Alternatively, type View and press Enter. The View Manager dialog box appears.
2 In the Views list, expand either Model Views or Layout Views (depending on where you saved the view).
3 Double-click the name of the view you want to restore, and then click OK to close the dialog box.
Degenerating and Regenerating
As you zoom and pan around the drawing, you may wonder how the image you see onscreen is related to the DWG file that AutoCAD saves on the hard drive. Well, maybe you don’t wonder about it, but I tell you in this section 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 this precision when you save the DWG file. For reasons of computer performance, however, AutoCAD does not use that high-precision form of the data to display the drawing onscreen. Instead, AutoCAD converts the highly precise numbers in the DWG file into slightly less precise integers in order to create the view you see onscreen.
The happy consequence of this conversion is that zooming, panning, and other display changes happen a lot faster than they would otherwise. The unhappy consequence is that the conversion can make circles and arcs look like polygons. AutoCAD solves this problem by regenerating the drawing (also known as performing a REgen operation).
In most cases, AutoCAD regenerates drawings automatically whenever it needs to. You sometimes see command-line messages such as Regenerating model or Regenerating layout, indicating that AutoCAD is handling the regenerating 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. In addition, you might see the warning message About to regen -- proceed?. AutoCAD is saying, “What the drawing looks like onscreen now may not exactly match the real version of the drawing database that’s stored when you save the drawing. I’ll update the display version at the next regeneration.”
You can control whether regenerations happen automatically by using the REGENMODE system variable. See the online Help system for more information on this variable, and see Chapter 23 for general information on system variables.
Almost every new release of AutoCAD has improved graphics performance. The program has come a long way from the so-called high-resolution 640 x 480 16-color