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3D sketching, and concept design usecases for IFC

One of the biggest issues faced by the architecture disciplines and existing BIM packages is that the programs optimised for OpenBIM and IFC are not optimised for concept stage design. This means that often architects mock up in other software, and then re-draft / re-model in a BIM package. This rework, and loss in translation seems to me like a perfect opportunity for IFC to be of use.

Here’s a little experiment I’d like to share of a concept-stage BIM scene started in Blender, and then exported into IFC, and brought into Revit. I had to use quite a few workarounds to get it to display correctly (e.g. most BIM software will not do 3D polyline colours and styles properly, even though IFC has them in the spec), so workarounds like using IfcSweptDiskSolid were required.

Here’s the original scene, similar to how an architect might envision a funky urban form.

… another angle …

Note: I did not create the design, original credits are:


Animated grease pencil demo file.
Blender 2.82 Splash Screen 

Credits: Andry Rasoahaingo - License CC-BY-SA 3.0

It was exported to a 7.1mb IFC file (yes, very small, and @jonm tells me it can be optimised further). Revit does a very good job of bringing it in, although there are a few quirks, and I’ve undoubtedly broken a few topological rules in the process. You can see that the scene is partially 3D modeled, partially 3D sketches, and partially even mock-up planes (see that 2D building and funky cat in the left half of the screenshot)

The linework is a little faint shown in that purple colour. You can see I’ve selected a stair and it comes through correctly as an IfcStair (or Revit’s internal stair category). Here’s another shot with clearer linework:

Revit also handles creation section cuts, and doing basic tagging and annotation.

… another section cut …

Still quite a few issues in the workflow, but I hope this raises the idea of IFC usecases from early concept phase. Improved support for 2D lines and 3D polyline styling in IFC could make this a very powerful tool.