When James Cameron casually suggests you take on one of his projects, you say yes. That’s exactly what Robert Rodriguez did when he learned that the Avatar director would be busy making endless sequels to that 2009 sci-fi film, leaving his long-gestating adaptation of the cyberpunk graphic novel Battle Angel Alita languishingThe Texan filmmaker shared that origin story for next year’s Alita: Battle Angel  back during a New York City Comic Con panel. Those in attendance didn’t just get more tidbits from the performance-capture heavy production; they actually got to see footage from the manga-inspired film. Starring a slew of A-list actors including Christoph Waltz, Mahershala Ali, Jennifer Connelly, Eiza Gonzalez and Michelle Rodriguez, this dystopian story centers on Alita (Rosa Salazar), a disembodied “core” who awakens with no memory in a post-apocalyptic world destroyed by a technological fall. Dr. Ido (Waltz) finds her and gives her a new body only to slowly find out that there’s more to this young girl-looking cyborg than meets the eye.

Cameron and Rodriguez aren’t the only big names to thank for this Latino-heavy blockbuster. It was Guillermo del Toro, in fact, who first shared Alita with James Cameron way back in 1999. And while the Titanic director was keen on shooting this film himself, he ultimately decided to pursue the world of Avatar instead. That left him to find someone else to take over. Rodriguez was all too happy to comply, partly because he was so in awe of the test reel Cameron showed him and the long-ass script he shared.

“I loved his script so much,” he told the crowd. “It was not like reading a script I usually read. When you read someone like Cameron or Quentin [Tarantino], these are writer-directors that, when you’re reading it, you’re seeing the movie they have in their head. And you love that movie!” But since the screenplay he’d been given was over 600 pages long, Rodriguez knew he had to trim it down. “You realize you can’t shoot one that’s that long. So I’m gonna pretend that it’s one that’s already been shot by him and I’m gonna be just an editor and cut things that may not be needed to get it to a more manageable approach.”

Rodriguez, who’s best known for his homegrown Texas and Mexico-set films, got to relish being in a production where budget wasn’t his main concern. Whereas in past films he’d needed to pitch in and shoot them himself – and even write their scores (despite not being a musician) – Alita: Battle Angel boasts the work of cinematographer Bill Pope (The Matrix, Spider-Man 2) and composer Tom Holkenborg (Mad Max: Fury Road). “I didn’t do all those jobs because I wanted more work,” he joked. “It was because I didn’t have any freaking money! This time it was like, ‘Oh I can get Bill Pope?'”

It explains why, even after working on the film for several years, he still feels more like an audience member than a director whenever he catches the finished product. Part of that is the groundbreaking special effects they’re using to bring Alita to life. With her big manga eyes and a cyborg body, the character Alita will be one of the most photorealistic CGI characters ever put on screen. Yet it’s still all Salazar, who had to train for five months to better tackle the feisty, fighting role. “I did some Muay Thai, Kung Fu, Kickboxing. It wasn’t just about the physical training. It also mentally prepared me,” she shared. “The thing about martial arts is that it’s mind, body and soul. It really helped me in all regards to take on this role.” After all, what better way to train to be a cyborg than to be strapped to a motion-capture suit, carry around a boom mic, and a camera on one’s head?

Alita: Battle Angel premieres February 14, 2019.