James Cameron and the 'Avatar 2' cast lived in a rainforest "for a few days" while making the movie.

The 67-year-old director headed to Kauai, Hawaii's fourth largest island, to get a real feel of the rainforest by cooking in underground fire pits and drinking water from the area's leaves.

He said: "I took the actors on what I called a sense-memory odyssey. We went to Kauai. We lived in the rainforest for a few days.

"We cooked in underground fire pits. We drank water from the leaves."

Cameron encouraged the cast to remember how they walked up steep sections of the rainforest and what the area smelt like.

Speaking to Variety, he added: "I said, 'All right, we’re going to walk up a trail and I want you to observe as much as you can about how you place your feet, how you place your hands when you go up a steep section. You’re going to have to remember it, what it felt like, what it smelled like, and you’re going to have to bring it back into a relatively sterile environment.'

"We all just embarked on that journey."

Cameron recently admitted 'Avatar 2' - the follow-up to his 2009 blockbuster - needs to "make a lot of money".

He said: "The big issue is: Are we going to make any damn money? Big, expensive films have got to make a lot of money.

"We're in a new world post-COVID, post-streaming. Maybe those numbers will never be seen again. Who knows? It's all a big roll of the dice."

Cameron noted how the upcoming movie - which stars the likes of Sam Worthington, Zoe Saldana, Stephen Lang, Sigourney Weaver, Kate Winslet, and Edie Falco among others - will allow him to bring together his "two greatest loves", directing and "ocean exploration".

He added: "It sounds kind of nuts, the process I mean, if 'Avatar' hadn't made so much damn money, we'd never do this - because it's kind of crazy…

"I do the ocean thing when I'm not making movies. So if I could combine my two greatest loves - one of which is ocean exploration; the other, feature filmmaking - why wouldn't I?"