Hi,
I’m trying to find a way to access Nodal masses using the FEM-Design Grasshopper API so I can compute the mass moment of inertia I_z within the script.
So far, the only solution I’ve found is to manually export the nodal masses as a batch (.bcs) file from the FEM-Design model and then import it into Grasshopper. However, because this step requires manual action, it cannot be integrated into a Galapagos script.
Has anyone solved this problem before or found a more automated approach? 
Thank you @MarcoPelle for you reply.
Yes, that’s a very helpful article. However, is it possible to generate a .bcs file directly using Grasshopper, without manually opening the FEM-Design model?
In my current workflow, I loop through different building layouts generated via the FEM-Design Grasshopper API, If I have to manually open each FEM-Design file to export the data, it breaks the automation, and I can no longer use Galapagos effectively.
ehi @Krisjanis
the bsc file for “Nodel masses” is not .str specific. You can see it as a generic file that can be reuse across different femdesign model.
Try to use the .bsc file even while optimising with Galapagos. It should work
Thank you @MarcoPelle!
I misunderstood how batches work - this really helped solve the issue!
