- Defining a custom coordinate system (V8i)

NOTE:  This article is specific to V8i.

MicroStation includes the ability to define a geographic coordinate system, and Bentley Map provides the tools to create and edit a new geographic coordinate system (GCS), ellipsoid or datum in a user defined library.  This new library can be shared with with all users. 

Create a custom geographic library:

Since the delivered library can't be edited, the following steps are needed to create a custom GCS libary.

• Copy the delivered seed library from c:\Program Files\Bentley\Map CONNECT Edition\BentleyMap\coordinate\seed.dty    to a location of your choice, for example c:\GCS_Libraries\MyCity.dty. 
• [Optional] A good location would be to place your DTY file in a sub-folder of your project Base Source Directory.
• [Optional] In the Geospatial Administrator, create a new file category in the Files node to include the DTY file. In the following example, Data was added for d:\Daily Work\Map Source Files\data\MyCity.dty

• Define MS_GEOCOORDINATE_USERLIBRARIES to point to your_location\your_file. Use the form Library[Name] where Library specifies the filename and the [Name] is the name of the root node for that library in the user interface. Multiple libraries can be specified by separating with a semi-colon. You can use a full file specification. If a directory is not specified, MS_GEOCOORDINATE_DATA is used.

Examples:

MS_GEOCOORDINATE_USERLIBRARIES = d:\data\ProjectABC.dty[Project ABC]

MS_GEOCOORDINATE_USERLIBRARIES = d:\data\ProjectABC.dty[Project ABC];d:\data\ProjectXYZ.dty[Project XYZ]

MS_GEOCOORDINATE_USERLIBRARIES = $(MS_GEOWSHOME)\data\ProjectABC[Project ABC]

• [Optional] If preferred, you can define this variable in the MACROS node of your user workset in the Geospatial Administrator.

• Start Bentley Map, select Geographic Coordinate System from the Utilities tab.
• From the Geographic Coordinate System tool palette, select From Library. Your user library will be displayed in the Library tab of the Select Geographic Coordinate System dialog.

To Create and Edit a User Coordinate System

Bentley Map does not let you edit any of the coordinate systems in the delivered library; rather, you copy an existing coordinate system, paste it in the user library and edit the copy.

• Start Bentley map with a configured workspace that points to a custom GCS.
• Locate the coordinate system to edit, or one that is similar to the one to add.
• Right-click the coordinate system entry and select Copy.

• Select the User library in the Geographic Coordinate System dialog and select Paste.  A copy of the selected coordinate system is pasted into the user library. Note:  Coordinate system names must be unique and cannot exceed 23 characters. It must contain at least one letter A to Z. It can contain any uppercase or lowercase letters, any digit from 0 to 9 or one of the following characters: _-$:.;~/ or spaces. Characters with accents or diacritic remarks are not permitted. Cases sensitive names are allowed but names must be unique when compared as uppercase. 
• To rename, select the coordinate system, right-click and select Edit Coordinate Systems Properties.

• A dialog displays allowing you to edit the name or other properties. Click OK when finished.

• Custom coordinate systems can be deleted by right-clicking and selecting Delete from Library.

• It is also possible to right-click on a coordinate system to Copy or to Add To Favorites.
• Edits to the coordinate systems libraries occur immediately. If a coordinate system is selected and you click OK in the Select Geographic Coordinate System dialog, it will be interpreted as wanting to assign that coordinate system to the DGN file.

Notes:

• Custom GCS, datum and ellipsoids can only be created with Bentley Map
• The resulting custom GCS library can be shared with any MicroStation user by defining the variable to point to the location of the custom library
• All names must be unique across the delivered and custom libraries
• A DGN with a custom GCS will behave correctly even if the library from which the GCS was defined is not available

• If you are using Bentley Map V8i through one of the Civil Engineering products, you must first Activate Map in order for the Edit menu item to be available.

• NOTE:  OpenCities Map CONNECT Edition is not delivered with the CONNECT Edition Civil products.