2011

6 On the Options tab, select the options you want.
■ To perform a coordinate conversion, you must have a coordinate
system
assigned to the map (page 147).
■ Check Treat closed polylines as polygons (if it is available) unless you
want only polygon objects to be exported as polygons.
7 Click OK to begin the export process.
Exporting To MicroStation Design (DGN) Versions 7 and 8
You can import and export Microstation DGN version 7 and 8. Bentley Systems,
Inc., and MicroStation programs use the DGN format, which is like a DWG
file; points, lines, areas, text, and other object types can all be present in the
same file.
NOTE When you export from a map, only drawing objects are exported. Geospatial
features are ignored. To move geospatial feature data to another format, use
Migrating GIS Data (Bulk Copy) (page 617).
Exporting
There are two separate choices for Microstation DGN (version 7 and version
8) in the Export dialog box. You can map layers in the map to DGN levels
when you export. The default is to map layers to level names using the same
name as the layer.
Geometry in DGN 7 files is stored in fixed-point integers. When you export
map data with large coordinate values, you can overflow these values with
unpredictable results. The seed file you use for export has a dramatic effect
on the resulting DGN data.
Every DGN file requires a seed file to give it default information (like the
acad.dwg prototype or template file). The seed file controls working units,
global origin, the version to export, and so on. Several seed files ship with
AutoCAD Map 3D.
The default for a version 7 DGN file is lrgseed.dgn. The default for a version
8 DGN file is lrgseed3d_v8.dgn. Both of these are three-dimensional seed files.
To export to a two-dimensional DGN file, or to set a specific global origin or
specific working units, reference the file name of the desired seed file. The
global origin and units of resolution should be set in a seed file that is
appropriate to your AutoCAD Map 3D drawing coordinates.
Exporting To MicroStation Design (DGN) Versions 7 and 8 | 1435