- Creating a New Drawing
- Model Space and Layout Space
- Communicating with AutoCAD
- Object Snaps, Ortho Mode, and Polar Tracking
- Grid and Snap
- Draw a Circle
- Navigating Around the Drawing
- Object Properties
- Dimension Styles
- Modifying Drawing Objects
- Grip Editing
- Introduction to Advanced Editing Techniques
- Cleaning Up Layout Space
- Plotting and Page Setups
- Chapter Summary
- Chapter Test Questions
As you saw in the previous exercise, some properties are common to all objects. These include color, linetype, lineweight, layer, and transparency. Color is fairly obvious; it is the display color of the object on the screen. Linetype refers to how the line is displayed—for example, a dashed line, dotted line, or continuous line. Lineweight is the plotted width of the object (think of it as pen width). Transparency controls the visibility of objects so you can see through them.
You can assign a color, linetype, lineweight, and transparency level to each object individually; however, when your drawing grows in complexity, you can quickly find it difficult to manage each object individually. This is where layers come to the rescue.
Layers give you a way to group objects together logically. The objects are still separate but share common properties and can be manipulated as a group.
Each layer consists of a name, color, linetype, lineweight, transparency level, and a number of on/off settings. When you draw an object, the properties of the current layer are applied to that object. The quickest and easiest way to manage layers is via the Layers panel on the Home tab of the ribbon shown in Figure 2-20. The Layer drop-down list allows you to set the current drawing layer (see Figure 2-20). The Layer Properties Manager palette allows you to create and manage drawing layers.
FIGURE 2-20 The Layers panel on the Home tab of the ribbon
So far, the appearance of your drawing hasn’t changed. All you have done at this point is to define some new layers.
The new lines have the color and linetype of the Center layer. The rest of the drawing was created on Layer 0. In the next exercise, you’ll move those objects from Layer 0 to the Object layer.
Of course, the objects didn’t actually move. Their layer property was simply changed from 0 to Object. However, you can think of this as the objects “floating” from one layer to another or (in the pin-board drafting world) moving the objects from one overlay sheet to another.
Freeze and Thaw a Layer
Your drawing objects are now organized into a few logical layers. Next we’ll look at some methods of manipulating layers in your drawing.
When layers are frozen, AutoCAD acts as though the objects on those layers don’t exist. Objects on frozen layers are hidden from view and cannot be changed while the layer is frozen. The current drawing layer cannot be frozen.
AutoCAD also has an On/Off setting for layers (represented by the lightbulb in the Layer drop-down list). While turning layers off will hide them from view, objects on those layers can still be modified (i.e., erased). For this reason, freezing and thawing layers is generally preferred to turning layers on and off.
Lock and Unlock a Layer
Although the Freeze option will prevent objects from being modified, it also hides them from view. The Lock/Unlock setting allows you to prevent objects from being modified while still keeping them displayed on screen.
This section has touched on only a few key elements of layering and AutoCAD’s layer management tools. Layer management is a crucial element of using AutoCAD effectively.