What would be simplest way to import an Alias nurbs model into Twinmotion? I have seems to try all the import solution but I'm really stuck. Any easy and direct workflow proposal? Would love to ...

Thanks for that explanation.

If you've already got your nurbs files saved to .udatasmith files, you should be able to import the .udatasmith files to Twinmotion directly without needing to convert them to other filetypes. Twinmotion reads .udatasmith files natively.

If that doesn't work, would you mind sharing one of your files for me to look at more closely?