Missing volume metadata after STP import in solid with void

helen-brooks · October 29, 2021, 10:45am

Coreform Cubit Version: 2021.4.0
Platform: Ubuntu 20.04
Python version : 3.8.12
PythonOCC version: 7.4.1-dev

Issue
I am generating a STEP CAD file using the python OCC package, and importing that STEP file into coreform cubit. It is desirable for my workflow to have volume name metadata in that file. I have found that for ordinary solids I can achieve this without issue, however for solids with voids cubit fails to import the metadata, despite it existing in the file in the same location.

I would like to know if this is a bug on the cubit side, or if the way the metadata is interpreted for hollow solids is different in cubit, and I need to somehow export this differently.

Please find attached the a minimal working example to produce two step files, a sphere and hollow sphere where the metadata is imported correctly into cubit for the former but not for the latter.
occ-metadata.py (2.2 KB)

helen-brooks · October 29, 2021, 10:46am

Since I could only upload 2 files at a time here are some additional details.
Here are the resulting step file outputs
HollowSphereTest.step (2.5 KB) SphereTest.step (2.0 KB)

helen-brooks · October 29, 2021, 10:47am

… and finally 2x screenshots of coreform cubit showing the metadata present and missing for the two files respectively.

karl · October 29, 2021, 6:17pm

Hi Helen,

Welcome to the forum. I don’t know enough about OpenCascade to give you any direction here. I can see what you are seeing in the STEP import files. They look like they are the same and should behave the same. This may be a bug. I will do a little more looking to see if I can understand what is going on in this case.

Thanks,
Karl