Thursday, May 22, 2008

The Holy Grail of IFC export / imports

Prodded by a comment on the IFC export / import capabilities of ACA 2009 and RAC 2009, I exported the out of the box "c_condo_complex.rvt" file to IFC and imported it in ACA.

This is how it looks in RAC. (Three floor plans and iso view)


This is how it looks in ACA. (Three floor plans as iso views and a View dwg that has all these levels xrefed into them.)


I used the "create new project" option.


The results are NOT at all satisfactory. However, when I used the split walls and columns in Revit, I got this. I guess, this should work, if I want to give this IFC to my MEP consultants who are working with AutoCAD for MEP. It brought walls, windows, doors as ACA objects. (style names are IFCStyle1, IFCSTyle2, etc.)


If anybody has done this or use this function often, please enlighten me. Some issues:

  1. Some walls are missing.
  2. Roof and wall interaction is not handled properly.

Surprisingly, when I imported the same IFC file into RAC 2008, it looked like:


This result had similar issues like ACA. (same exterior walls missing, roof/wall bad improper interaction) It brought back same wall styles (as in RAC2009), etc. Which is great, but it seemed to happen only on the first floor level. Upper floor windows and doors have become in-place familes!!!


Tomislav Zigo said...

It is not ACA inability to bring in IFC, but Revit's is not translating its geometry in the way it should with the default settings. In order to verify IFC file integrity get yourself a true IFC viewer, or bring the file into Navis Works!


Nicholas said... are here!
Yes. Navisworks might show it correctly. However, we are trying to translate RVT project into Autocad using IFC.

Tomislav Zigo said...

Bad idea, whether you got from RAC to ACA or vice versa those object are quite useless as both applications lose most of the parametric object qualities. In my experience you will have a better luck bringing ACA ifs into RAC as ACA allows you to map the IFC entity types and the associated properties via classifications.
Just one more RAC tip. When building within RAC environment start thinking as an estimator, it will help you with the IFC translation.

Cheers, and sorry for not replying sooner as I was on the road the entire last week.


Rob said...

Is there a list of how Revit translates out as IFC content? I am trying to outline conversion from BIM to GIS and breaking down the class types for specific focus.


Nicholas Iyadurai said...

Sorry. I am not aware of any such list.
I am sure translating from rvt to gis must be a daunting task!