Another way to create symbols is by creating shapes. Shapesare special objects made up of lines, arcs, and circles. They can regenerate faster than blocks and they take up tes, He space. Unfortunately, shapes are considerably more difficult to create and less flexible to use than blocks.
You create shapes by using a coding system developed by Autodesk. The codes define the sizes and orientations of lines, arcs, and circles. You first sketch your shape, convert it nto the code, and then copy that code into a DOS text file. You can also use the Make type Expresstool described in Chapter 19 to create a shape from an AutoCAD draWing book doesn’t go into detail on this subject, so if yOLjwant to know more about srapes, seeyourAutoCAD Customaetion Manual.
Another way of using symbols is to use AutoCAD’s external reference capabilities. External referenced files, known as Xrefs, are files inserted into a drawing in a.way similar to blocks. The difference is that Xrefs do not actually become part of the drawing’s database. Instead, they are loaded along with the current file at startup time. It is as if AutoCAD opens several drawings at once: the
main file you specify when you start AtitoCAD, and the Xrefs associated with the main file.
Blocks are an extremely useful tool, but for some situations, they Ciretoo restricting. At times, you lwill want to group objects together so they are connected, yet can still be edited individually. For example, consider a space planner who has to place workstations in a floor pIC!? Though each workstation is basically the same, there may be some slight variationsin each station that would make the use of blocks unwieldy. For instance, one workstation may need a different configuration to accommodate special equipment while another workstation may need to be slightly larger than the standard size. A better way is to draw a ; rototvpe workstation and then turn it into a group. The group can be copied in, then edited for each individual situation, without the group losing its identity group. The following exercises demonstrate how this works
1. Open the drawing named off; eel. dwg from the companion CD-ROM
2. Use the Zoom command to enlarge just the view of the workstatio, as shown in the top image
3. Choose Tools Object Group, or use the keyboard shortcut G.J. The Object Grouping dialog box appears
4. Type Stationl. As you type, your entry appears in the Group Name input box.
5. Click New in the Create Group button group, about midway in the dialog box. The dialog box temporarily disappears to allow you to select objects for your new group.
6. At the Se1ect obj ects: prompt, window tl1e entire workstation and press .J. The Object Grouping dialog box returns, Notice that the name Stat; on appears in the Croup Name list box at the top of the dialog box.
7. Click OK. You have just created a group.
Now, whenever YOll want to select the workstation, you can click any part of it and the entire group is selected, At the same time, you can still modify individual parts of the group-the desk, partition, and so on-without losing the grouping of objects.
Modifying Members of a Group
Next, you will make co, lies of the original group and modify the copies. Figure 4.9 is a sketch of the proposed l.iyout that uses the new workstations. Look carefully and you’ll see that some of the workstations in the sketch are missin&a few of the standard components that exist in the Stationl group. One pair of stations has a” partition removed: another station has no desk.
This next exercise shows you how to complete your drawing to reflect the design requirements of the sketch.
1. Click Copy on the Modify toolbar or type Co.J, and click the Stationl group you just created. Notice that you can click any part of the station to select the entire station.
2. Press .J to finish your selection.
3. At the Base poi nt: prompt, enter @.J. Then enter @8’2″<90to copy the workstation 8 feet, 2 inches vertically. Metric users should enter @249<90Cory command again, but this time click the copy of the workstation you just created. Notice that it, too, is a group.
5. Copy this workstation 8’2″ (249cm) vertically, just as you did the orvinal workstation.
6. Need U use grips to mirror the first workstation copy. Click the rniclle workstati it, and notice that grips appear for all the entities in
7. Click the grip iri the middle-left side, as shown in Figure 4.10.
8. Right-click the mouse and select Mirror from the popup list. notice that a ternpory mirror image of the workstation follows the movement of your cursor.
9. Turn on the Ortho mode and pick a point directly to the right of the hot grip . you picked in step 7. The workstation is mirrored to a new orientation.
10. Press the Ese key twice to clear the grip selection.
Now that you’ve got the workstations laid out, you need to remove some of the partitions between the new workstations. If you had used blocks for the workstations, you would have to first explode the workstations whose partitions you wish to edit. Groups, however, let you make changes without undoing their grouping.,
1. Press Ctrl+A, This temporarily turns off groupings. You’ll see the mesage<Group off> in the Command window
Using a window, erase the short partition that divides the two copies of the workstations, as shown in Figure 4.11.
Press Ctrl+A again to turn groupings back on. You’ll see the message <Group on> in the Command window.
To check your workstations, click one of them to see if all of its components are highlighted together.