Autodesk 00128-051462-9310 - AUTOCAD 2008 COMM UPG FRM 2005 DVD, User Manual

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Anchors
An anchor links an AEC object to another object or to a layout curve or grid. You can create anchors between objects
and also remove anchors from objects. AEC objects can be anchored to each other, to AutoCAD objects like lines and
circles, or to layout curves or grids.
Automatic and user-defined anchors enable you to use anchors for many different purposes.
Automatic and User-Defined Anchors
Automatic anchors are set by the program. Certain objects are by default anchored to other objects. For example, doors
and windows are usually anchored to walls. Curtain wall units or window assemblies might be anchored to curtain
walls. Although these anchors are inserted automatically, when you place the objects their behavior can differ slightly.
For example, a door that is anchored to a wall can be moved to an unconnected wall. The door cannot, however, be
moved outside a wall and stand alone. To do this, you must remove the anchor between door and wall. The anchor of
a column to a column grid behaves differently: you can move the column inside the grid, but you cannot move the
column to another grid without first removing the anchor.
User-defined anchors are manual links that you can create between two objects. Most anchors are used with layout curves,
layout grids, or volumes. You can also attach anchors to other AEC objects or AutoCAD objects.
Anchoring objects to a layout curve can be useful for positioning washbasins along a wall or rafters along a roof.
Anchoring objects to layout grids can help you to position columns on a column grid, planters on a sidewalk grid, or
tile accents on a floor tile grid. For information about layout curves or grids, see “
Using Layout Curves ” on page 1474
and “ Using Layout Grids ” on page 1482.
Types of User-Defined Anchors
There are six different types of anchors that you can use to attach objects:
Then… If you want to…
use object anchors. attach AEC objects to other AEC objects
use curve anchors. attach AEC objects to the base curve of other objects, such as lines,
arcs, circles, mass elements, polylines, roofs, or walls
use leader anchors. attach objects to nodes on layout curves or grids with leaders
use node anchors. attach objects to nodes on layout curves or grids
use cell anchors. attach objects to cell positions on 2D layout grids and 3D volume
grids
use volume anchors. attach objects to volumes on 3D grids
Working with Object Anchors
You can use object anchors to attach an AEC object to the base curve of another AEC object. When an AEC object is
anchored to another AEC object, it will be moved together with the anchoring object. When the anchoring object is
deleted, the anchored object will be deleted, too. Changes that are made to the anchored object, however, will not be
replicated in the anchoring object.
When the anchored object is selected, a temporary graphic displays the anchor. The temporary anchor graphic contains
a trigger grip to release the object anchor.
Mass element anchored to a wall
1454 | Chapter 30 Anchors