To Create a Polygon Topology

Polygon topology is an extension of network topology and focuses on area-based relationships. Every area forms a polygon; and each polygon in a topology consists of a set of links. A polygon in a topology has a centroid, which is a point or block element within the polygon, and contains information about the area it encloses.

To create a polygon topology

1. Do one of the following to bring linework into the current drawing:
   • Attach the drawings containing the linework. Query the linework into the current drawing.
   • Open the drawing containing the linework.
   • Import the linework from another file format.
2. Click Create tabTopology panelNew. Find
3. In the Create Topology - Select Topology Type dialog box:
   • Under Topology Type, click Polygon to indicate that you want to create a polygon topology.
   • Enter a Topology Name and Topology Description for your new topology.
   • Click Next.
4. Follow the on-screen instructions to specify the objects to use to create the topology. You can also have AutoCAD Map 3D create any missing nodes and centroids.
   • Use the Create Polygon Topology - Select Links dialog box to select the linear objects to use to generate polygons for the topology. To use a closed polyline to create polygon topology, you must first explode the closed polyline.
   • Use the Create Polygon Topology - Select Nodes dialog box to select the node objects to include in the topology.
   • Use the Create Polygon Topology - Create New Nodes dialog box to have AutoCAD Map 3D create node objects where needed. Specify the layer and block to use for the new node objects.
   • Use the Create Polygon Topology - Select Centroids dialog box to select the centroids to use.
   • Use the Create Polygon Topology - Create New Centroids dialog box to create centroids where needed. Specify the layer and block to use for the new centroids.
5. In the Create Polygon Topology - Set Error Markers dialog box, indicate whether to highlight and/or mark detected errors with blocks. AutoCAD Map 3D automatically checks for Missing Centroids and Intersections. Additionally, you can choose to have AutoCAD Map 3D check for Duplicate Centroids, Incomplete Areas, and Sliver Polygons.
   • To highlight errors with red Xs, select Highlight Errors.
   • To mark errors with blocks of the shape and color you specify, select Mark Errors With Blocks.
   • In the Marker Size box, specify the marker size as a percent of the screen size. A value between 3% and 7% is usually suitable.
   • If you chose the Mark Errors With Blocks option, specify the shape and color of the block to use to mark each error.
6. Click Finish to create the polygon topology.

   To remove highlighting, use the REDRAW, REGEN, or SAVE command. To remove an error marker, select it and press Delete.

7. If appropriate, save the topology information back to source drawings.