Most major shoe companies employ fashion designers to develop their designs but they also employ 3D modelers to help bring those ideas to life and to help develop prototypes.

Sometimes that requires and understanding of AutoCad, but ZBrush, Mudbox and Maya are also used and useful.

Vans has openings right now for 3D modelers, for instance. http://sites.vans.com/careers/corp/usa/openings/        >>> look under designer

New Balance also has 3D Production Artists positions open: https://jobs.newbalance.com/job/lawrence/3d-production-artist-3/810/8740751

New Balance has a one year 3D Production Artist Internship open as well…  https://jobs.newbalance.com/job/lawrence/3d-production-artist-intern-one-year-internship/810/7582436

UnderArmour internship applications for summer 2019 open November 20 and close December 14. Candidates are encouraged to apply early because the internships are awarded on a rolling basis.