The Intergraph Standard File Formats ISFF are the file formats
common to MicroStation and Intergraph’s Interactive Graphics
Design System IGDS ISFF is now available to the public This
enables Intergraph customers and third party developers to create
custom applications for MicroStation that read and write ISFF
format without a license from Intergaph
reading and writing DGN files It is based in the OpenDGN initiative developed by Bentley Systems which is known as a leading supplier of CAD software Consequently DGNdirect provides compatibility with Bentley MicroStation V7 ">The Intergraph Standard File Formats ISFF are the file formats
common to MicroStation and Intergraph’s Interactive Graphics
Design System IGDS ISFF is now available to the public This
enables Intergraph customers and third party developers to create
custom applications for MicroStation that [更多]
DGNLib is a small C/C++ library for reading and writing DGN files.
Where can I get the source code?
dgnlib-1.11.zip: Current standalone source with dgndump example mainline.
Does DGNLib support all DGN elements?
No, but it does support most 2D and 3D elements. Some of the more esoteric elements are read in "raw data mode", but not interpreted. It does support lines, line strings, curves, bsplines, ellipses, arcs, and text elements, as well as extracting color tables, and master coordinate information.
Does DGNLib support Microstation V8 DGN Files?
No, they are a substantially different format, and are not recognised at all. The DGNdirect library from the OpenDWG Alliance does support DGN v8.
Is it portable?
Yes, fairly, though as distributed it may be necessary to tweak the cpl_port.h and cpl_config.h files for different platforms. It was developed on Linux for a client deploying on MacOS, and Windows.
Does it require alot of memory?
Generally speaking no. Only one element at a time is kept in memory. If the file is "indexed" an additional 12 bytes per element is kept in memory after a pre-scan, but this isn't required.
Does DGNLib include code to draw DGN elements?
No, but there is a document that tries to indicate how to properly draw DGN elements given the structures returned by DGNLib. The OGR layer re-interprets the drawing information into OGR Feature Style format which is understood by some applications such as UMN MapServer.
What is the license?
DGNLib is under my usual MIT/X style open source license. Thus is can be easily used in commercial, and free products with no concern about licensing issues. See the header of any source file for the full license text.
Is there support for writing DGN files?
Yes, there is preliminary support for writing 2D and 3D DGN files in recent releases.
Is there documentation?
There is a detailed DGN Library API Reference available. There is currently no tutorial style information on how to use the library, but the dgndump.c utility can serve as a limited example.
Is further work going on to improve the library?
The initial project is complete, but I am interested in fixing bugs and adding minor features. Improvements are welcome.
1 Introduction Introduction Introduction Introduction
Originating in the late 1970s, drawing files created with microcomputer-based computer-aided design software were saved with the .dwg extension. In the early 1980s, Autodesk® released AutoCAD® which eventually became the most used CAD software in the world and which used Autodesk’s undocumented and proprietary DWG™ file format (using the .dwg extension).
The Open Design Specification for .dwg files serves AutoCAD’s undocumented and proprietary DWG file format. This specification includes DWG file format versions 13 up to and including version 2013. Further, the Open Design Specification for .dwg files serves the Teigha® software development platform of the Open Design Alliance.
While our Open Design Specification for .dwg files is able to read and write .dwg files with excellent AutoCAD compatibility, we continue to work to improve our understanding of all the data in a .dwg file. If you find information which will help us to understand any unknown values, please contact us at http://www.opendesign.com/contact.
