It's no secret that Lucasfilm has had some problems with the directors of their new slate of Star Wars movies. Incidents of hiring and firing have been heavily reported, which only makes it more clear just how trouble-free the production of Star Wars: The Last Jedi seems to have been. There's been extremely little -- if any at all -- behind-the-scenes drama, but that doesn't mean director Rian Johnson didn't face challenges. Johnson had a difficult time crafting the space battle of The Last Jedi, mostly because those sequences are entirely digital and thus harder to judge.
Honestly, the most technically challenging stuff are the space battles because those are the ones where, aside from the cockpits, nothing is real. The practical effects, and especially the creature workshop, was much more fun.
Lucasfilm has made a lot of effort to use practical effects in the new Star Wars trilogy when it can, but no modern blockbuster set in the middle of space can go without using come CGI. The days of models dangling on strings are long past, and technology has advanced enough to produce truly eye-popping effects. However, that doesn't make them easy to film. In an interview with SciFiNow Magazine (via ComicBook), director Rian Johnson revealed that the most technically challenging part of filming Star Wars: The Last Jedi was filming the space battles. As opposed to, say, a lightsaber duel, which is anchored by real actors, the space battles are entirely digital. You're essentially handing the reigns to the digital effects team and hoping that it'll look good.
Despite that challenge, it looks like everything is working out for Rian Johnson and The Last Jedi. The sequel is incredibly hyped thanks to some plot-stingy trailers and it's projected to have a massive opening in December (though, perhaps not as big as The Force Awakens). Everything from the sequel has looked great so far, and Lucasfilm is clearly very happy with the work Johnson has done. Rather than have him direct Episode IX, Johnson has been tasked with crafting his very own Star Wars trilogy, which will feature all-new characters and settings. Hopefully, he learned enough about space battles during The Last Jedi!
Star Wars: The Last Jedi takes place sometime after the events of Star Wars: The Force Awakens. Rey has found Luke Skywalker and is training under him to harness her growing Force powers. Meanwhile, Finn is on a mission for the Resistance and questioning his role in the conflict, all while Kylo Ren and Supreme Leader Snoke plot their next move.