2011

NOTE This procedure applies only to drawing objects. To perform buffer analysis
on geospatial feature data, see
To create a buffer (page 1308).
To buffer a topology
1 In Map Explorer (page 2068), under Current Drawing, right-click a topology
➤ Analysis ➤ Buffer.
2 In the
Topology Buffer - Set Buffer Distance dialog box (page 1992), enter
the buffer distance. Click Next. The buffer extends the specified distance
from the objects.
The buffer offset can be any of the following:
■ Numeric value. To decrease the size of existing polygons, enter a
negative value.
■ An expression that evaluates to a numeric value.
■ A value in an object data table or a linked external database. Click
(Expression Evaluator) to select the table and field or the link
template and column from a list.
NOTE If you are creating a buffer around a polygon and want to use a
value in an object data table or an external database, the data must be
attached to the centroid of the polygon.
3 In the Topology Buffer - New Topology dialog box, select Highlight to
highlight the resulting buffer topology onscreen. Specify a highlight color
that is different from the color of the objects.
4 Enter a name and description for the new topology and specify the layer
to place it on. Click Next.
NOTE If you specify a locked layer, AutoCAD Map 3D can create the buffer
geometry but not the buffer topology.
5 In the Topology Buffer - Create New Centroids and Nodes dialog box,
specify the blocks to use for centroids and node in the resulting buffer
topology.
■ To use a point, select ACAD_POINT.
■ To select from a list of block definitions, click the down arrow.
■ To select a block saved as a DWG file, click Browse. Select the file.
Buffering a Topology | 1347