Anomaly/Error Extracting Part Geometry

Hi All,

I’m using this post to extract the geometry of individual layers from a wall instance (converting to parts, extracting geometry, rolling back transaction), but the geometry this returns (for one of the parts) doesn’t match what’s modelled.

In the below image the selected layer is the internal face of the wall, but the retrieved geometry of this part (blue outline) is different.

The geometry on the left is the part in Revit, on the right is what is being extracted in Dynamo.

I’m trying to get accurate areas and volumes for these layers for 800+ wall instances so I need to be confident the geometry I’m interrogating is accurate.

Any help massively appreciated.



First thing that comes to my mind is changing the geometry working range:

And check if it makes any difference.

Hi Viktor,

Thanks for the reply, changing the working range made no difference though.

I’m beginning to think this might be a Revit problem.

Hi Alex!
Thanks for posting this thread. I’m actually struggling the same problem right now and I’m curious if you were able to solve this issue? In my case the geometry extraction works occasionally, but in most cases I get similar result, that is, some parts are imported to Dynamo correctly, and others ignore the window opening.

Hi Karolina, unfortunately not :frowning:

Ok, so I’ve got some clues on this topic:

  1. Dynamo interprets parts correctly if the sampled geometry is disconnected,
  2. If the sampled walls are joined together Dynamo will mess up the actual parts geometry. (see images below)

Which is kind of weird, but maybe someone can come up with the reasonable explanation and eventually overcome to this?