GML Translators

Q) What is GML and why might I want to translate it?

A) GML is short for Geography Markup Language. It is an open (i.e. not proprietary) format for storing geographic type data. You might want to translate it if you receive some GML data and want to use it. Alternatively, you might have geographic data in your system that you want to share with some else. Translating your data into GML would be one way to do this.

The dhp11 Translators

We're MicroStation focused so our translators convert MicroStation design files (DGN's) to GML text files and vice versa. If you don't use MicroStation or the MicroStation DGN format then you probably don't need our translators.

DGN and GML Import/Export Translators

image/right external:http://www.dhp11.com/site04/product/gmltranslator/images/gml09.png? The DGN and GML Import/Export Translators are the latest products from dhp11 Ltd. These translators have been written for Microstation SE/J and allow the translation of:

1. Design File (DGN) elements to GML/OS MasterMap features
2. GML/OS MasterMap features to Design file (DGN) elements

What is OS MasterMap?

The OS MasterMap file format is an implementation of XML called GML. OS MasterMap is the new digital format from Ordnance Survey GB. It is derived from the Digital National Framework and is will eventually replace the existing Land-Line family of products. The OS MasterMap format has improved on other land-line formats in various ways. The data is clean: all polygons are closed, there are no crossing lines or gaps, and the accuracy has improved. The data contains complete polygons of builds, fields, etc, and can be filled and be represented more clearly.

GML2DGN? Import Module

The GML2DGN? Import module translates GML/OS MasterMap information into Microstation design files (DGN). The Importer allows complete flexibility in how individual features are translated. This means that the operator can choose to translate GML to DGN features using the supplied 'default' settings, or, if required 'customise' the 'translation' settings to create features within a DGN file that are specific to an individual operator/organisation.

The GML2DGN? dialog allowing import of GML features to their DGN file equivalent

Importing features/settings

The GML2DGN? Import module comes - as standard - with a default feature settings/symbology file. This allows GML/OS MasterMap data to be imported without any user intervention being required.

If the operator does require non default settings to be used - the 'Importer' does allow the display/settings of individual features.

This allows the operator to have complete control over how the GML/OS MasterMap data appears within the DGN file. When importing data - the symbology (colour, style, weight, level etc..) of an individual features can be set, or if required, the translation of specific GML/OS Mastermap feature(s) can be prevented.

Importing spatial (attribute/database) information

Aswell as allowing 'geographic' information to be Imported (creation of feature/elements within a DGN file) the Importer also allows spatial (attribute) information to be used to populate existing database tables.

For any information that is imported into an existing database table a 'link' is automatically created within the DGN file between the 'new' database table row and the 'new' feature/element created in the DGN file.

DGN2GML? Export Module

The DGN2GML? Export module allows existing DGN feature/elements (linear, shape, text and points/cells) to be exported to a GML file. Using the DGN2GML? Export module to generate GML files means that an existing application able to read GML data, can have direct access to geographic/attribute information previously held in a DGN format file.

The DGN2GML? dialog allowing export of Design File elements to their GML file equivalent

Exporting features/settings

The DGN2GML? Export module allows the operator to identify/select specific features to be 'exported' to GML. This allows the operator to select: The types of features to export The type of information to be exported for a specific feature Specific features can be identified for export using feature/element symbology (element type, colour, style, weight, font etc..), and attribute/database information (if available). The feature types that can be exported include: Linear, Point/Cell, Shape, Text The type of information that can be exported for a specific features includes: Spatial (attribute/database) information from associated database tables Specific feature codes/names XY coordinate information Point/Text orientaion, scale, text/string name Text height, font, justification Shape features (including holes)

Exporting spatial (attribute/database) information

Aswell as exporting 'geographic' information (i.e. X,Y coordinates, orientation, height etc..) from an existing DGN file - the DGN2GML? Export module also allows attribute/database information (associated to a specific feature) to be exported to GML.

This means that, a GML record (created from an existing DGN feature) can contain not only 'geographic' (X/Y coordinate) information, but - if required - spatial (database/attribute table/column) information for a specific feature aswell. The Exporter allows the operator to specify specific database fields to be exported as 'attribute' data to a GML file. For example - an individual feature within a DGN file may have an associated record in an existing database table. e.g. A database table may contain the fields FeatureCode?, Text, X, Y.

The DGN2GML? module allows the operator to export, for a specific feature, information for either, a single field/column (i.e Text) from an existing database table, or export information from ALL fields/columns of an existing database table.

GML - An open format

The dhp11 Ltd 'DGN and GML Import/Export Translators' allows data to be easily exchanged between the DGN and GML file formats. The DGN2GML? Export module means data, originally held in the DGN format - and therefore inaccessible to other systems, can now be exported to GML and accessed freely by other applications.

The GML2DGN? Import module not only allows Ordnance Survey OS MasterMap data be imported, but means information held by any other systems can now (if the applications allows) be exported from these systems to a GML format, and be imported/accessed from within Microstation. This means that all files created by the dhp11 Ltd 'DGN and GML Import/Export Translators' can be used directly by any other system/application that recognises the GML/OS MasterMap file format.

NOTE: The GML files created by the DGN2GML? 'Export' module conform to the standard supplied by Ordnance Survey with their own OS MasterMap data. As from March 2003 OS MasterMap data was supplied in GML 2.1.2.

See also

UTG0 Export Module Related Documentation

UTG0 Export Config File
UTG0 FeatureCollection File

GTU0 Import Module Related Documentation

GTU0 Import Config File
GTU0 Template File