(by hiron_rgkr)
HoaryFox read Japanese structure BIM file named ST-Bridge file(.stb) and display its model. It also convert to karamba for structural analys.
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Grasshopper Component which read ST-Bridge file(.stb) and display its model information.
You can easily check frames and present structure frame!!
If you need stand-alone ST-Bridge file viewer, Please see STEVIA
As a test function, it creates an analytical model of Karamba from st-bridge data.


  1. In Grasshopper, choose File > Special Folders > Components folder. Save the gha file  there.  If you want to use Karamba convert, it is super recommended to save the file in the same directory as Karamba.gha
  2. Right-click the file > Properties > make sure there is no "blocked" text
  3. Restart Rhino and Grasshopper 

How to use

  • Input st-bridge file path, output some its tag data(StbColumn, StbGirder, StbPost, StbBeam, StbBrace, StbSlab, etc).
  • Support for ST-bridge ver2.0 is now available from HoaryFox ver1.1.  
  • Please refer to Samples files.

Convert to karamba

Conversion of data into Karamba supports only beam elements. Mesh elements such as floor and wall are not supported.
L-type and C-type cross-sections are replaced by rectangular cross-sections with equivalent axial cross-sections because Karamba does not support them.

What is ST-Bridge

Quote from building SMART Japan Structural Design Subcommittee doing making specifications of ST-Bridge.

ST Bridge is the standardized format for data sharing in Japan’s structural engineering industry.

  • Simpler to use than IFC due to the clearly defined the range of use
  • Integrate Japanese original methods of drawing methodology (Grids, part placement and section annotations, reinforcement information)
  • Aim for coordination between domestic structural applications, building skeleton surveying applications, 3D Object CAD