Hard to believe but it has been 6 years since 20th Century Fox released James Cameron's technological breakthrough Avatar, which shattered box office records left-and-right and finished its run with $2.7B.

The Oscar-winning filmmaker has spent the past several years working on scripts for three Avatar sequels with screenwriters Josh Friedman, Rick Jaffa, Amanda Silver and Shane Salerno. All three scripts were expected to be completed by July of 2014, but in a new interview Cameron says they still need polishing.

"I’m in the process of doing another pass through all three scripts right now," Cameron told Entertainment Weekly. "Just refining. That’s in parallel with the design process. The design process is very mature at this point. We’ve been designing for about a year and a half. All the characters, settings and creatures are all pretty much [set]."

Interest in the Avatar sequels isn't as high as one would expect. Its biggest impact on our culture has been so many films being filmed, or more often converted to, 3D to take advantage of higher ticket prices.

Can Cameron even come close to duplicating the first film's success? "Obviously, expectations are going to be very high on these films, especially on Avatar 2, to make sure it wasn’t just some big fluke the first time," Cameron admitted. "So we’ve got to deliver. I’ve created a nice rod for my own back, so they say."

The as yet untitled Avatar sequels will be filmed back-to-back-to-back. The release of the first follow-up is expected in December 2017, with the second to follow in December 2018, and the third a year later.