Bob Mason | Applications Expert
There have been comments which bring up some very good questions concerning coordinate transformation. A 2D transformation works pretty smoothly when utilizing Autodesk Map as the coordinates are being moved to the desired coordinate system with little effort. There are however a few extra steps that come into play when working with the 3D element. Largely this depends on what type of file you currently have and from what program it was created (i.e. Microstation or ESRI). Typically, if you just have an ACAD drawing that contains polylines with elevations, both the 2D and 3D elements of the geometry need to be transformed.
Once we know the type of file we’re working with, there are different scenarios that may be used to perform the transformation.
In this example, let’s assume a situation in which you have an ACAD DWG that includes polylines with elevations. First, export the data to an ESRI SHP file which can then be imported into a new drawing. The ESRI SHP file can include other information such as Meta Data which can also be very useful. Since the ribbon changes a bit from version to version, I will suggest using the MAPEXPORT command...
- A dialog box appears prompting for the location; ensure you select ESRI Shapefile for the file of type.

- The Export dialog box includes 3 tabs (Selection, Data, Options)

- Selection Tab
- Define the Object type
- Select the objects
- Filtering the selection gives the ability to specify layers or classes
- Options Tab
- Coordinate conversion
- This should be populated with the current coordinate system of the file.
- Check “Convert coordinates to:”
- Select the coordinate system you would like to apply to the file.


You now have a SHP file which includes the geometry you exported. Now you can Import the SHP file back into a new drawing using the MAPIMPORT command.
- In the Import Location dialog box select the file you just created.

- In the Import dialog box you will define the import properties to be imported.

- The Drawing Layer column can be selected to define which layer you want to put the geometry on. Leaving the default layer creates a layer with the drawing name.
- Ensure the Input Coordinates column displays the desired coordinate system.
- Select the option to Import polygons as closed polylines.
- Select OK

You will need to Zoom Extents to see you drawing. Depending on the layer you selected could give you varying results on the colors and linetype, but, the geometry should be in the new coordinate system as well as at the proper location.
Again, there are other scenarios which can be used to import the 3D data after knowing specifically what type of file you are starting with.
Hope this helps moving you in the right direction.