We're still a few months away from Warner Bros. Dune (hopefully) hitting theaters just in time for the holiday moviegoing season. However, Dune helmer Denis Villeneuve is getting a head start on hyping up the forthcoming sci-fi epic based on the first novel Frank Herbert's groundbreaking science fiction series and boast one of the most star-studded casts of 2020. Over the course of a special 50-minute conversation conducted for the 2020 Shanghai International Film Festival, Villeneuve opened up about the thought process behind casting each Dune actor. ICYMI, the cast for Dune is massive, but …