Importing Surface as landXML issue

Hi,

When I import a surface triangulation from Autocad as a landXML file, the triangulation in Kubla seems to ignore the boundaries I set in Autocad. 

For example an "S" shaped driveway would join the extents so it would look like a rectangle. 

Is their a way I can import with the boundaries set so I just have the driveway shape?

Screenshot link 
https://drive.google.com/drive/folders/1...drive_link

Hi Martin,

Thanks for bringing this issue to our attention—the screenshots you provided were very helpful.

I took a deep dive into this, as I’ve seen similar cases before, and it didn’t seem credible that either Autodesk or Kubla would “invent” triangles like this. While I was confident Kubla isn’t adding triangles, I couldn’t initially understand why Autodesk would either. However, I believe I’ve found the explanation, detailed at the end of this post: Correctly export LandXML surface (without additional triangulation).

It turns out there’s an attribute in LandXML surfaces used to mark triangles as “ignored.” These triangles existed at some point, but were later deleted and marked with this attribute in case they might be needed in the future.

For your reference, the internal Kubla issue tracking this is titled:

Roadmap Item 4480 | LandXML does not support 'ignore' attribute when importing faces.

Currently, Kubla doesn’t recognize the “ignore” attribute in LandXML files. I’ll speak with our developers to see if we can add support for this in the next update. I imagine it would be a relatively simple fix—just ignoring triangles marked with this attribute during import.

Workarounds

In the meantime, here are a couple of suggestions:

Export as DWG: This format doesn’t support the “ignore” attribute, so it should resolve the issue by exporting only the active triangles.
Manually Edit the LandXML File: Open the LandXML file in a text editor (e.g., Notepad) and delete the faces marked with i="1". This will remove the ignored triangles before importing into Kubla.

Let me know if you have further questions or need assistance with these workarounds!