Assigning Layers to Objects

Assigning Layers to Objects
When you create an object, that object is assigned to the current layer. Until now, only one layer has
existed—layer 0—which contains all the objects you’ve drawn so far. Now that you’ve created
some new layers, you can reassign objects to them by using the Properties palette:
1.
Select the four lines that represent the bathroom walls. If you have trouble singling out the
wall to the left, use a window to select the wall line.
2.
With the cursor in the drawing area, right-click, and choose Properties from the shortcut
menu to open the Properties palette. This palette lets you modify the properties of an object
or a set of objects. (See the upcoming “Understanding Object Properties” sidebar for more on
the properties of objects.)
3.
Click the Layer option on the list in the Properties palette. Notice that an arrow appears in
the layer name to the right of the Layer option.


4.
Click the downward-pointing arrow to the far right of the Layer option to display a list of all
the available layers.
5.
Select the Wall layer from the list. Notice that the wall lines you selected change to a green
color. This tells you that the objects have been assigned to the Wall layer. (Remember that
you assigned a green color to the Wall layer.)
6.
Close the Properties palette by clicking the X button in the upper-left corner.
The bathroom walls are now on the new layer called Wall, and the walls are changed to green.
Layers are more easily distinguished from one another when you use colors to set them apart.
Next, you’ll practice the commands you learned in this section and try some new ones by creating
new layers and changing the layer assignments of the rest of the objects in your bathroom:
1.
Open the Layer Properties Manager dialog box (choose Format 
Layer, or click the Layer
Properties Manager button in the Layers control panel). Create a new layer called Fixture,
and give it the color blue.
TIP
You can change the name of a layer by clicking it in the Layer Properties Manager dialog box.
After it’s highlighted, click it again so that a box surrounds the name, or press the F2 function key.
You can then rename the layer. This works in the same way as renaming a file or folder in Windows.
2.
Click the Tub and Toilet blocks, and then right-click and choose Properties from the shortcut
menu to open the Properties palette.
3.
Click Layer in the list of properties, and then select Fixture from the drop-down list to the
right of the layer listing.
4.
Click the X in the upper-left corner of the Properties palette to dismiss it, and then press the
Esc key to clear your selection.
5.
Create a new layer for the door, name the layer Door, and make it red.
TIP
In a block, you can change the color assignment and linetype of only those objects that are on
layer 0. See the sidebar “Controlling Colors and Linetypes of Blocked Objects,” later in this chapter.
6.
Just as you’ve done with the walls and fixtures, use the Properties palette to assign the door
to the Door layer.
7.
Use the Layer Properties Manager dialog box to create three more layers for the ceiling, door
jambs, and floor, as shown in Table 5.1. Remember that you can open the Select Color dialog
box by clicking the color swatch of the layer listing.


Understanding Object Properties
It helps to think of the components of an AutoCAD drawing as having properties. For example, a line has
geometric properties, such as its length, and coordinates that define its endpoints. An arc has a radius,
a center, and beginning and ending coordinates. And even though a layer isn’t an object you can grasp
and manipulate, it can have properties such as color, linetypes, and lineweights.
By default, objects take on the color, linetype, and lineweight of the layer to which they’re assigned, but
you can also assign these properties directly to individual objects. These general properties can be
manipulated through both the Properties palette and the Properties toolbar.
Although many of the options in the Properties palette may seem cryptic, don’t worry about them at
this point. As you work with AutoCAD, these properties will become more familiar. You’ll find that you
won’t be too concerned with the geometric properties, because you’ll be manipulating them with the
standard editing tools in the Modify toolbar. The other properties will be explained in the rest of this
chapter and in other chapters.
In step 3 of the previous exercise, you used the Properties palette, which offered several options for
modifying the block. The options displayed in the Properties palette depend on the objects you’ve
selected. With only one object selected, AutoCAD displays options that apply specifically to that
object. With several objects selected, you’ll see a more limited set of options because AutoCAD can
change only those properties that are common to all the objects selected.
Controlling Colors and Linetypes of Blocked Objects
Layer 0 has special importance to blocks. When objects assigned to layer 0 are used as parts of a block,
and that block is inserted on another layer, those objects take on the characteristics of their new layer.
On the other hand, if those objects are on a layer other than layer 0, they maintain their original layer
characteristics even if you insert or change that block to another layer. For example, suppose the tub is
drawn on the Door layer, instead of on layer 0. If you turn the tub into a block and insert it on the Fixture
layer, the objects the tub is composed of will maintain their assignment to the Door layer, although the
Tub block is assigned to the Fixture layer.
It may help to think of the block function as a clear plastic bag that holds together the objects that make
up the tub. The objects inside the bag maintain their assignment to the Door layer even while the bag
itself is assigned to the Fixture layer. This may be a bit confusing at first, but it should become clearer
after you use blocks for a while.
AutoCAD also enables you to have more than one color or linetype on a layer. For example, you can use
the Color and Linetype buttons in the Properties palette (the Properties button on the Standard toolbar)
to alter the color or linetype of an object on layer 0. That object then maintains its assigned color and
linetype—no matter what its layer assignment. Likewise, objects specifically assigned a color or linetype
aren’t affected by their inclusion in blocks.