Buffering a Topology
Concept Procedure Quick Reference
NoteThis procedure applies only to drawing objects.

To buffer a topology

  1. In Map Explorer, under Current Drawing, right-click a topology Analysis Buffer.
  2. In the Topology Buffer - Set Buffer Distance dialog box, 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.
  6. Click Finish to create the buffer topology.