Working with Drawings Productively
In previous releases of AutoCAD, to edit a drawing you simply opened it. Although this technique works fine in many editing situations, it can be a slow, tedious process if you’re working with large drawing files. As a consequence, many technicians have developed procedures that help limit a drawing file’s size, thereby increasing AutoCAD’s response time when opening drawings and executing commands. One of these techniques included separating a large drawing into a group of smaller drawings. In some situations, a drawing was divided into a tiled grid, and each grid exported as its own drawing file. In other situations, a drawing was isolated by different layers, with each layer and all its objects saved as a single drawing file. Whichever method was used, the intent was the same: to decrease the drawing’s file size and thereby increase productivity through faster response by AutoCAD.
The Partial Open and Partial Load features provide the ability to simulate the advantages achieved when separating a drawing into smaller files without the need to divide the original drawing into groups of smaller drawings. These new features allow you to open only a portion of a drawing, thereby loading only the elements you need to edit. Objects can be loaded based on selected layers by choosing a predefined view, or by windowing in on an area. When you’ve finished, simply save the drawing normally. This feature enables you to maintain a high level of productivity even while working on large drawings, and it avoids the management problems encountered by separating a single drawing into many smaller drawings.
AutoCAD 2002’s Partial Open Feature
The Partial Open feature allows you to open a portion of a drawing by either selecting the drawing’s extents or the last view when the drawing was saved, or by selecting a predefined view if one exists. After you select the desired view option, you identify the object geometry you wish to load by selecting the layer(s) on which they reside.
The following exercise demonstrates how to use AutoCAD’s Partial Open feature.
Exercise 14.1 Using the Partial Open Feature
1. |
From the File menu, choose Open. The Select File dialog box appears. |
2. |
From the accompanying CD, select the 14DWG01.DWG drawing file. The drawing appears in the Preview window as shown in Figure 14.1. Next, you load only a portion of the object geometry from the drawing. Figure 14.1. The Partial Open feature is accessed from the Select File dialog box.
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3. |
Click the down arrow next to the Open button then choose the Partial Open option. AutoCAD then displays the Partial Open dialog box. |
4. |
In the View Geometry to Load area, choose Area 1. This instructs AutoCAD to load objects that lie within or pass through the predefined view named Area 1. |
5. |
In the Layer Geometry to Load area, select the check boxes next to layer names BUILDINGS, CONTOURS-INDEX, and CONTOURS-NORMAL, as shown in Figure 14.2. This instructs AutoCAD to load objects on the selected layers. Figure 14.2. The Partial Open dialog box allows you to identify the object geometry to load by selecting the view and the layers in which the objects reside.
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6. |
Close the drawing; do not save your changes. |
AutoCAD opens the drawing, loading only the objects that lie within or pass through the view, and that reside on the selected layers, as shown in Figure 14.3. At this point, you can edit the loaded geometry, create new objects, and zoom or pan the drawing. You can also create and modify data outside the area you opened. You are not limited by the initial view when working with partially opened drawings.
Figure 14.3. The Partial Open feature loads only the objects that lie within or pass through the selected view, and that reside on the selected layers.
When you used the Partial Open feature in the previous exercise, you selected a view and three layers. However, it is not necessary to select layers. You can select a view, but leave all the check boxes next to the layer names cleared. If you do, when you click Open, AutoCAD issues a warning that no objects will be loaded. However, AutoCAD does load all the layer names, and also loads all the other named objects such as blocks, text styles, dimension styles, and linetypes. Once the drawing is partially opened, it is possible to use these named objects to create new object geometry in the drawing without actually loading any existing geometry.
Another behavior unique to the new Partial Open feature occurs when you save and then reopen a drawing that was partially opened. When you reopen the drawing, AutoCAD displays a warning noting that the drawing was partially opened when last saved. This warning, and the options it presents, is described in the next section.
AutoCAD 2002’s Partial Load Feature
The Partial Load feature allows you to load additional geometry into a drawing that is already partially opened. By using this feature, you can further refine the selection set of objects you load into the current editing session.
The following exercise demonstrates how to use AutoCAD’s new Partial Load feature.
Exercise 14.2 Using the Partial Load Feature
1. |
From the File menu, choose Open. The Select File dialog box appears. |
2. |
From the accompanying CD, select the 14DWG02.DWG drawing file. The drawing was created at the end of the previous exercise by saving the partially opened 14DWG01.DWG drawing file. Notice that the drawing’s image does not appear in the Preview window. This is because the drawing was saved while only partially opened. |
3. |
Click the Open button. AutoCAD displays a warning noting that the drawing was partially opened when last saved, as shown in Figure 14.4. Figure 14.4. AutoCAD displays a warning when you select a file that was partially opened when last saved.
AutoCAD presents three options for handling the file. By clicking the Fully Open button, you load all the drawing’s object geometry. This is how AutoCAD normally opens a drawing. By clicking the Restore button, you partially open the drawing using the previous Partial Open settings. By clicking the Cancel button, you stop AutoCAD from loading the drawing and create a new drawing instead. |
4. |
Click the Restore button. AutoCAD partially opens the drawing using the previous Partial Open settings that were saved with the drawing. |
5. |
From the File menu, choose Partial Load. AutoCAD displays the Partial Load dialog box. This dialog box is almost identical to the Partial Open dialog box. The main difference is the Partial Load dialog box includes the Pick a Window button, which allows you to drag a selection window around the area from which to load objects. |
6. |
In the Layer Geometry to Load area, select the check box next to the CENTERLINE layer name. This instructs AutoCAD to load objects on the selected layer. |
7. |
Click the Pick a Window button, as shown in Figure 14.5. When AutoCAD temporarily removes the dialog box, create a window selection around the circle, after which AutoCAD redisplays the Partial Load dialog box. Figure 14.5. The Partial Load dialog box allows you to pick an area from which to load windowed objects.
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8. |
Click OK. AutoCAD loads the objects within the defined area and on the CENTERLINE layer, as shown in Figure 14.6. Figure 14.6. The objects within the defined area and on the CENTERLINE layer are partially loaded.
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9. |
Close the drawing and do not save changes. |
AutoCAD’s Partial Open and Partial Load features allow you to load specific objects into the current editing session. By using these features, you can reduce the time it takes to open a drawing and to execute AutoCAD’s commands, and thereby increase productivity.