IFC to Rhino - Extract Geometric Representation for Volume Calculation

I’m hoping to get some volumetric takeoffs from an IFC model for some LCA calculations, but have hit a wall in terms of extracting the geometric information from the model in order to calculate the volumes. While I can see the elements in the viewer, I can’t find the fields within the Speckle import to get the volumes of the meshes (though it looks like this is currently an open issue)

To try and get around this, I instead loaded the stream data into grasshopper, hoping I’d be able to convert the objects into native Rhino meshes and get the volumes and attach the volumes to the objects to push back up the stream. However, after exploding the speckle objects, I still can’t isolate the geometric data (though I can see the objects in Rhino).

IFCVolumes.gh (14.3 KB)

Is there a way to expose the geometric information for each object which is appearing in Rhino?

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Hey @m-clare!

Thanks for bringing this up! I guess this is due some documentation or blog post to clarify a bit how our IFC import works, and what assumptions do we make.

When importing an IFC file, we try to keep the data structures as close to the original as possible, but there is one big difference in Speckle that I think is what’s causing you confusion:

For every item that has some geometric information, a mesh representation of that element will be attached to the displayValue property. This is the same behaviour that the Brep class, and all of the BIMand Structural elements work.

So basically, I think you’re looking for this :point_down:

Let me know if this is not exactly what you were looking for, we’d be happy to poke around at your use-case :slight_smile:

On a side note, the IFC import service still has quite some room for improvement, so we’d love to hear your thoughts on what works, what doesn’t and what you’d wish to see in it in the future!


Great post and use-case! @m-clare :grinning:!! I was wondering @AlanRynne if it is possible to give IFC parameters to the geometry in Rhino?

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