Over a decade separates the releases between the first film and Avatar: The Way of Water. But director James Cameron wasn’t just dilly dallying away behind the scenes. In fact, he recently explained the “hideously difficult” process of filming human actors–like Jack Champion’s Spider–alongside Na’vi in the sequel with cinematographer Russell Carpenter.

Speaking with Vanity Fair, the duo explained the lighting process behind Avatar 2 and how certain scenes were shot two times years apart with Spider. “Because he was in so many scenes, in so many different environments, you really have to nail down exactly when and where and how the light is and maybe where shafts of sunlight are hitting,” Carpenter said. “If any of those cues are off, the audience goes, ‘Wait, something’s out of whack.’ And so we worked really, really hard.”

Cameron followed this up elaborating about how Champion did motion capture for Spider first before filming scenes as …