Hi Nastasia! For this particular workflow, I imported a custom part into C3D's Content Catalog Editor and built a custom catalog that way. Please note that this particular workflow is a little dated though, as newer releases leverage Infrastructure Parts Editor, as you mentioned. Custom parts being imported into Infrastructure Parts Editor needed to be developed inside Inventor. I have some good experience with Infrastructure Parts Editor and have developed several custom catalogs. If there's a particular part you're looking to develop that I can assist with, please feel free to reach out to me at stevewalz@hotmail.com to discuss further!
