It took a while before work on "Avatar 2" ramped up and it is because the underwater motion-capture technology director James Cameron has planned on using for the film also took a long time to perfect. Unfortunately, the final product will not be seen until 2020, but cast member Stephen Lang recently shared his experience on working with the new tech and its style of filming.

While promoting his project "Braven," he discussed to Screen Rant how Cameron's underwater mo-cap breaks boundaries to bring an underwater world in the film to life. Here is what he had to say:

"Well, in ways that are probably too numerous or too, kind of, complex or too subtle for me to even articulate right now. I mean, look it's no secret that we're doing a lot of underwater motion capture, which, in itself is groundbreaking, it just hasn't been done."

According to him, it presents a host of challenges but those are nothing to Cameron whom he implies is no stranger to shooting sequences involving plenty of water. As he put it, the underwater world is "extremely beautiful, fascinating, and challenging" even to him. "So, you know, there's sections that taker place. . . so, that in itself is a big deal," he added. "But just, what are we, three months into shooting now, it's like nothing I've done before."

As for the sequel itself, Lang reassures it will not stray too far from its roots. The actor says it is in many ways, reminiscent of the original film, describing it as "Avatar on steroids."

Lang will reprise his role of Miles Quaritch who served as the primary villain of 2009's "Avatar." Sam Worthington (Jake Sully), Zoe Saldana (Neytiri), and Sigourney Weaver (Dr. Grace Augustine) are expected to return as well.

"Avatar 2" is currently scheduled to open in cinemas on Dec. 18, 2020, with additional three follow-ups premiering on Dec. 17, 2021, Dec. 20, 2024, and Dec. 19, 2025, respectively.