2004

Work with Layers | 175
Use Layers to Manage Complexity
You can reduce the visual complexity of a drawing and improve display
performance by controlling the number of objects that are displayed or
concealed. For example, you can use layers to control the visibility of similar
objects, such as electrical parts or dimensions. Also, you can lock a layer to
prevent objects on that layer from being accidentally selected and modified.
Control the Visibility of Objects on a Layer
You can make drawing layers invisible either by turning them off or by freez-
ing them. Turning off or freezing layers is useful if you need an unobstructed
view when working in detail on a particular layer or set of layers or if you
don't want to plot details such as reference lines. Whether you choose to
freeze layers or turn them off depends on how you work and on the size of
your drawing.
Turn off, rather than freeze, the layer if you frequently need to switch the
layer's visibility. When you turn on a layer again, the objects on the layer are
redisplayed automatically.
Freeze a layer if you do not need to see the objects on that layer for a long
time. You redisplay frozen layers by thawing them, and thawing one or more
layers causes the drawing to be regenerated. Freezing and thawing layers
takes more time than turning layers on and off.
Objects on turned-off layers are invisible, but they still hide objects when you
use
HIDE. Objects on frozen layers do not hide other objects.
In a layout (paper space), you can make some layers invisible only in certain
viewports.
Assign Default Color and Linetypes to a Layer
Each layer has associated properties such as color and linetype that are
assumed by all objects on that layer. For example, if the Color control on the
Properties toolbar is set to
BYLAYER, the color of new objects is determined by
the color setting for the layer in the Layer Properties Manager.
If you set a specific color in the Color control, that color is used for all new
objects, overriding the default color for the current layer. The same is true for
the Linetype, Lineweight, and Plot Style controls on the Properties toolbar.
The
BYBLOCK setting should be used only for creating blocks. For more
information, see “Control the Color and Linetype Properties in Blocks” on
page 323.