Question about pyiges features

[antonioneto223]

Hello,

I would like to ask if it is possible to extract the NURBS information (such as knot vectors, control points positions and weights, ...) from the IGES file using the pyiges? In my program, I need that information to generate a mechanical model.

Regards,
Antonio.

[akaszynski]

... if it is possible to extract the NURBS information (such as knot vectors...

Yes, and I'm sorry the docs were lacking and nearly non-existent. You can grab all that information from the RationalBSplineSurface objects resulting from Iges.bspline_surfaces().

I've updated the docs here https://pyvista.github.io/pyiges/, and you can find the B-REP surface definition here at RationalBSplineSurface

Let me know if that makes sense, or if the docs need more work.

[antonioneto223]

Hi,

Thanks very much. I was able to fully understand the functions and get the information I needed.

However, I had some problems when reading an IGES file exported by the Rhino software, which I use to generate my models. There were no problems at all with IGES generated by SolidWorks, for instance (like the impeller.igs used as an example). Do you have any guess about the difference between those IGES files that could have led to the problem?

[akaszynski]

I'm not sure why there's a difference, but if you upload the file here I can take a look at it and see what the issue is.

[antonioneto223]

Sure, there is the IGES file generated from Rhino, named ex.iges.

And I really appreciate your attention to help me, thank you very much

ex.zip