2011

Exporting
DWG files can contain multiple geometry types, while SHP files contain only
one. Each ESRI SHP file stores a single type of spatial data: point, line, text, or
polygon. The text SHP files contain attribute text associated with points.
When you create a multi-polygon in AutoCAD Map 3D and then export it to
SHP format, it will appear in its native SHP file as a multi-polygon (a polygon
with multiple exterior rings).
When you export, AutoCAD Map 3D automatically filters the selected objects
and exports the correct type of object to the corresponding SHP file. The
filenames produced by the export operation use the name of the feature class
followed by the geometry type, for example, PARCELS_POLYGON.SHP.
NOTE You cannot name a SHP feature class FeatId. This is a reserved name.
Export Options
You can export a single object to a single file, or you can export multiple
objects to a set of files. There are two methods for multi-file export.
■ The single-file option
Unless you have modified the MapExport.ini file, choosing ESRI Shapefile
from the drop-down list in the Export dialog box exports a single geometry
type to a single SHP file. You specify the geometry type on the Selection
tab of the Export dialog box.
■ The MapExport.ini folder export option.
You can
modify the initialization file (page 269) to include all object types
when exporting drawing objects to ESRI SHP format. This will remove the
object type options and display File Name Prefix field on the Options tab
of the Export dialog box, which lets you create a folder of SHP files using
this prefix, appended by each object type name.
This method is effective when you export all the geometry from a DWG
file and visual fidelity is more important than the preservation of classes
and attributes.
All objects of the same geometry type will be grouped in a single SHP. For
example, if pipes, roads, and streams are all represented by lines, you will
export one SHP containing the geometry and attributes for all three object
types. If streams have attributes that are not shared by pipes, those
attributes will have null values for pipes.
To create polygons in the SHP files using the folder option, you must select
the Treat Closed Polylines As Polygons option. To export closed polylines
as lines, select the Line object type. To export closed polylines as polygons,
Exporting to ESRI SHP | 1425