Another tool for organization is the layer. Layers are like overlays on which you keep various types of information (see Figure 4.12). In a floor plan of a building, for example, you want to keep the walls, ceiling, plumbing fixtures, wiring, and furniture separate, so you can display or plot them individually or combine them in different ways. It’s also a good idea to keep notes and reference symbols about each element of the drawing, as well as the drawing’s dimensions, on their own layers. As your drawing becomes more complex, the various layers can be turned on and off to allow easier display” nd modification.
For example, one of your consultants may need a plot of just the dimensions and walls, without all the other information; another consultant may need only a furniture layout. Using manual drafting, you would have to redraw your plan for each consultant. Wit~1AutoCAD, you can turn off the layers you don’t need and plot a drawing containing only the required information. A carefully planned layeringscheme helps you produce a document that combines the different types of information needed in each case.
Using layers also enables you to modify your drawings more easily. For example, suppose you have an architectural drawing with separate layers for the walls, the ceiling plan, and the floor plan. If any change occurs in the wall locations, you can turn on the ceiling plan layer to see where the new wall locations will affect the ceiling,
and then make the proper adjustments. AutoCAD allows an unlimited number of layers, and you can name each layer anything you want.
Creating and Assigning Layers
To continue with your bathroom, you will create some new layers.
1. Open the Bath file you created earlier in this chapter. If you didn’t create one, use the file 04b-bath. dwgfrom the companion C.D.ROM.
2. To display the Layer Properties Manager dialog box, click the Layers tool in the Properties toolbar, or choose Format > Layers from the pull-down menu. You can also type LA.J to use the keyboard shortcut
Layering allows you to use a single AutoC.AO drawing for multiple purposes, A singl(‘drawing may serve to show both the qenorat layou] of the plan, and more detailed informillion sudr as equipment layout or fl()(“.fp,h:ng’layout. These two reproductions of the 10wN level show how one floor. pl~n file was used for two difrr~renll)ur~)osf’s, The top view shows the layout of nisbinqs and the bottom view logout. In each case, the same floor plan file was used, but in the upper panel, the pavmq inforrnation is on a layer that is turned off, layprs also’ facilitate the use of differing scales in the same drawing, Frequently, it smallscale drawing of an overall plan Will «mtam the same data for an enlarged view of other portions of the plan; such as astairwell or elevalor Lore, The detailed Information, such as notes.and dimensions, mlI.WN that is turned off for the overall plan.
3. Click the New button in the upper-right comer of the dialog box. A new layer named Layer 1 appears in the list box. Notice that the name is highlighted. This tells you that by typing, you can change the default name to something better suited to your needs.
4. Type Wall. As YQ1.} type, your entry replaces the Layer 1name in the list box.
5. Click the Show Details button, also locatedin the upper-right corner of the dialog box. Additional layer opti~s appear.
6. With the Wall layer name highlighted, click the downward-pointing arrow to the right of the Color drop-down list. You see a listing of colors that you can assign to the Wall layer.