"Avatar" may have been the top-grossing box office hit of all-time, but the public has so far only seen a tiny part of the world introduced in the futuristic epic.
That is revealed by Stephen Lang, who played one of the baddies in director James Cameron's landmark 2009 movie set on the imaginary world blessed with natural riches Pandora.
The 62-year-old New York-born actor, who plays a similar villain in new thriller "Pioneer" out this week, recounted the adrenaline rush of working on "Avatar," which has made an estimated $2.8 billion to date.
It is to be followed by three sequels in 2016, 2017 and 2018, each of which has an estimated budget of at least $300 million.
"It is kind of awesome, being part of (a big venture like 'Avatar') that involves so many different jobs all coming to this world Pandora come together," he told AFP in an interview.
For the actor, famous from 2011's "Conan the Barbarian" and the TV series "Law and Order," one of the challenges of 'Avatar" was spending so much time in front of a green screen, used for computer generated imagery (CGI).
Actors therefore had to use a lot of imagination, in a production planned down to the millimeter.
"We all need to be on the same page, as to where things are, how the weather is" on the fictional planet, in contrast to say "a cold day in Chicago (when) you don't need to act it."
- "World of Pandora is wider' -
Asked if "Avatar" could run out of steam over three more films, Lang insisted: "The world of Pandora is wider, with many creatures and tribes and a whole host of characters."
"I have a lot of faith in our storyteller, James Cameron. He created a very rich world. We've only seen one slice of it," he added.
Filming on the first sequel in the adventures of Neytiri, the blue beauty played by Zoe Saldana and paralyzed Marine veteran Jake Sully (Sam Worthington), will begin next year in New Zealand and California.
In "Avatar," Lang played the unscrupulous Colonel Miles Quaritch, and he is in baddie mode again for "Pioneer," in which he co-stars with Wes Bentley from current Oscar-tipped space epic "Interstellar."
The thriller, directed by Norwegian Erik Skjoldbjaerg (who made 1997's "Insomnia"), is based on a true story during the start of Norway's oil boom in the 1980s.
The mystery centers on two brothers who are divers involved in drilling for oil in the depths of the North Sea, and caught up in a story involving murky financial interests.
The film takes a conspiracy theory twist, but Lang stresses that "no doubt there were a lot of mistakes made in good faith" in the drive to find oil, which has made Norway a hugely wealth country.
"It was a question of trial and error. There was a lot of error no doubt about that," he said.
The movie's director said controversy continues to this day.
"There is an ongoing conflict between some of the divers and the government, who are supposedly responsible for some sort of neurological traumas that the divers suffered after the experiments," said Skjoldbjaerg.
"So the subject is still controversial in Norway," he added, noting that the case is currently under review at the European Court of Human Rights in Strasbourg, France.