AutoCAD For Dummies. Ralph Grabowski

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СКАЧАТЬ 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.

      

In both AutoCAD and AutoCAD LT, you can set named views to be current without having to open the View Manager dialog box. From the Views panel on the View tab, simply choose a named view to restore from the drop-down list.

      

You also can plot the area defined by a named view. See Chapter 16 for instructions on plotting views.

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.

      

The REgenAll command, available only from the command line, regenerates all viewports in a paper space layout. If you run the REgenAll command in model space, it has the same effect as the ordinary REgen command.

      

If you zoom in a long way in a large drawing that has small circles and arcs and you find them converted into hexagons, simply run the REgen command. You can also minimize this effect in the future by running the VIEWRES command and increasing the value from the default of 1,000 to as high as 20,000 although doing so can also slow down a complex drawing. This value is stored in the current drawing, so you can set up the template file (covered in Chapter 4) to cover most of your work.

      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 Tecmar Graphics Master adapter, which I started with in the 1980s.

Part 2

      Let There Be Lines

IN THIS PART …

      Draw lines and other mostly linear objects, as well as the curvy bits.

      Find out how to draw objects with precision.

      Manage object properties.

      Select and edit objects.

      Set up a paper space layout in anticipation of printing.

Chapter 6

      Along the Straight and Narrow

      IN THIS CHAPTER

      

Drawing linear things with the AutoCAD drawing commands

      

Lining up for lines and polylines

      

Closing up with rectangles and polygons

      As you may recall from your crayon-and-coloring-book days, drawing is fun. Computer-aided drafting (CAD) imposes СКАЧАТЬ