Whether she is on the cover of Vogue, a Victoria's Secret advertisement or a Parisian runway, Rosie Huntington-Whiteley is rarely seen looking anything less than flawless.
When she had to spend six months in the dirt and dust of a West African desert to shoot the movie Mad Max: Fury Road, which is in Singapore cinemas now, the 28-year-old model found she had no choice but to stop worrying about how she looked.
"Two weeks in, I was like, 'Ugh, f*** it, I don't care,'" she says at a press event in Los Angeles. "You were at the mercy of the desert and the film."
The Briton is one of three models-turned- actresses who earned supporting roles in the widely anticipated movie by George Miller, who also wrote and directed the three original Mad Max films from 1979 to 1985 starring Mel Gibson.
The other two models Abbey Lee, 27, and Courtney Eaton, 19 - both Australians - felt the same way.
"We all wore sweats and Ugg boots for six months when we weren't shooting," Lee recalls.
"I found it a real relief. I like to get my hands and feet in the dirt and the dust. But just to let go of the physicality of oneself and immerse yourself in this desolate, mad world was nice, you know? Not to have to worry about how you looked, I liked it."
Eaton adds: "You kind of gave up in the dirt. It was fun."
In Mad Max: Fury Road, an action-adventure set in a post-apocalyptic wasteland ruled by ruthless warlords, Tom Hardy and Charlize Theron play rebels who try to liberate the concubines of the warlord who controls the water supply.
Playing the repulsive tyrant's wives are Huntington-Whiteley, Lee, 27, and Eaton, 19, and American actresses Zoe Kravitz, 26, and Riley Keogh, 25.
In trying to recreate the arid, other-worldly landscape of his imagination, Miller dragged the cast to the desert Namibia in south-west Africa for the shoot.
Kravitz, the daughter of singer Lenny Kravitz and actress Lisa Bonet, says the conditions on set were harsh. "It was actually very cold," says the actress, who along with the other wives wears a thin, bedsheet-like white dress throughout the film.
It was tough mentally, too, which had the young women turning to one another for moral support.
Kravitz adds: "It was six months of severe isolation. We relied on each other and were attached to each other in this really bizarre kind of way. Everything was challenging, on the mind and the body and the spirit."
Although they had little acting experience under their belts, the women learnt a lot from Hardy, acclaimed for his performances in dramas Warrior (2011) and Bronson (2008), as well as from Theron, who won an Oscar for the film Monster (2003).
Many of their scenes were shot with both actors in the cab of a truck, where they could closely observe the way the seasoned performers work.
"What was interesting was getting to literally sit behind both Tom and Charlize for that length of time and seeing how they both tackled their characters," says Huntington-Whiteley, whose only movie credit before this was 2011's Transformers: Dark Of The Moon.
"Their methods are very different: Charlize will be cracking a joke right before they shout 'action' and then she's finishing it off when they say 'cut'. Tom's very quiet with his process, he's quite insular."
Theron, in particular, became a role model for her rookie co-stars. "She was our protector in the film and our protector in real life," says Eaton, who like Lee had never acted before.
Kravitz, who has had supporting roles in films such as X-Men: First Class (2011), says it was inspiring to watch Theron "give 150 per cent every single time 'action' is called and in between takes, have a good laugh". "She knew everyone by name and it was a really big crew. She's a kind person and extraordinarily talented."
While the "wives" were no doubt cast in part for their looks, it was important for both of them and Miller that they be more than just set dressing.
Miller - whose film has been praised for its feminist leanings, especially in having Theron's character Furiosa be a strong female counterpart to Hardy's Max - created impressively detailed backstories for each of the wives and even had the actresses meet feminist playwright Eve Ensler (The Vagina Monologues) to discuss them.
Ensler talked to them about her work with female Congolese rape survivors, whose experiences informed the characters of the wives.
"We all felt we didn't want to play a bunch of 'glamazons' in the back of a car," Kravitz says.
"But we knew pretty much right away after spending some time with George that that was a very important thing to him as well. And when we found out Eve was coming, we were excited. She kind of whipped us into shape - she really tried to have us understand what it meant to be used as an object and the reality of that."
Huntington-Whiteley agrees and says the movie is nothing short of groundbreaking in its approach to female characters.
"I think it's an interesting time for women and I'm really excited that this film represents women in a new way. And I think we all feel very privileged to be able to play such strong women."
Mad Max: Fury Road is showing in Singapore.