It took James Cameron 13 years to make the follow-up to “Avatar” (2009). That time was spent making the sequel, “Avatar: The Way of Water” (2022), even more technologically groundbreaking than its predecessor. While the first movie’s water-based scenes were actually shot on a dry set, the director and his crew built a performance-capture stage that actually worked both underwater and above the surface. But to get the clearest reference footage possible, the cast had to learn to hold their breath for extended time periods. That way, Sigourney Weaver and Kate Winslet could act out scenes underwater without worrying about breath bubbles obscuring their faces. The crew could also translate Sam Worthington, Zoë Saldana, and Stephen Lang’s performances to their Na’vi counterparts with even more accuracy thanks to a helmet with two cameras attached to it that was first developed for “Alita: Battle Angel” (2019).