Most of the first act of “Avatar 4” has been completed and most of the film has been designed, producer Jon Landau revealed at a press conference during the Busan International Film Festival on Thursday.

“We’ve completed most of the first act of ‘Avatar 4’ and there were logistical reasons why we needed to do that,” Landau said in response to a question from Variety. “We’ve designed most of the whole movie for ‘Avatar 4’ but we haven’t actually filmed all of it – just the first act.”

Landau addressed the media after showcasing 15 minutes of footage from “Avatar: The Way of Water” at a sold-out event at the festival, during which he talked up the cutting-edge technology used in the film. Director James Cameron appeared via video link at the event and discussed the film’s underlying ecological message and also talked about the film’s high-frame rate projection.

Later, Landau told the media: “We could not have delivered what people saw today, five years ago, eight years ago, nine years ago. We needed the time to take it to the level that we’re able to deliver to people today.”

Landau also revealed that each sequel would introduce a new culture, while retaining the cultures introduced in the previous films. “With each sequel, we’re going to introduce audiences to new cultures and new biomes. We don’t leave behind the cultures that we’ve met,” Landau said.

The producer also discussed the inclusivity in the “Avatar” films. For example, in “Avatar: The Way of Water,” the protagonists are refugees who seek safe harbor with people who don’t look like them and live differently than them.

“As filmmakers, we have a responsibility to use our art form to challenge people to see things differently,” Landau said. “And science fiction allows us the opportunity to be a metaphor for the world in which we live without preaching about it. Because if you preach, you only reach those who are already converted.”

“Avatar: The Way of Water” will begin rolling out theatrically across the world from Dec. 14. The first “Avatar” released in 2009 and grossed $2.9 billion, making it the biggest box office hit of all time. It re-released in late September this year and has earned nearly $60 million so far.