Friday, 31 December 2010

IFC Shape Representations

In response to the discussion on IFC Shape Representations on the IFC Linkedin group I decided to implement some further shape representations as examples and to find out other software reading and exporting models utilizing them.  From previous posts and comments, it seems like SCIA engineer might not have too many companions in recognizing and utilizing shapes other than the standard extrusions and faceted breps (which are often approximations).  I'm sure there might be some slight amendments I might make to the tags of the representations (I've implemented them as best I can interpret the informal propositions) but it's difficult to clarify them as examples of these files seem scarce.

Feel free to try and import these models into your BIM software (including viewers), and either comment or email me and we can tally which shape representations can be used with other software.

 A bounded plane surface : Grasshopper Model  IFC Export

 A revolved area solid : Grasshopper Model  IFC Export

A section spine solid : Grasshopper Model  IFC Export
Note that IFC does not explicitly define the surface geometry between the section spine profiles, I've used Rhino loft for the time being.

A swept solid : Grasshopper Model  IFC Export 
(I need to implement IFC curve parameterizations for more curves so this component is hidden for the time being)


  1. Unfortunately it is not possible to import any of these files into Scia Engineer..

  2. I tried with Solibri Model Viewer:

    bounded plane > nothing (project - site - building and then nothing)
    revolved area solid > rectangular extrusion (nothing revolved!)
    section spine > nothing
    swept solid > rectangular extrusion, but looking quite correct!

    And then with ArchiCAD 14: nothing shows up. Only the main structure (project - site - building)