Lars Von Trier: 'If I am an idiot in the eyes of the world, so be it'

A sweltering summer day at Filmbyen, the former military barracks outside Copenhagen where filmmaker Lars von Trier's production company is based, and the Danish director is in his golf cart, driving to have his picture taken. Now in his mid-fifties (he was born in 1956), von Trier is in good humour. It's hard to believe that this plumpish, bearded, Mr Magoo-like man in spectacles who likes cracking jokes and is so hospitable to visitors manages to stir up quite so much controversy.

When interviewed a little earlier in the day in his cabin at the edge of the barracks, von Trier lay down, as if he was being psychoanalysed. He had plenty to ruminate about. Three months ago in Cannes, at the press conference for his latest film Melancholia (a family melodrama/apocalypse movie), he made some wildly ill-judged remarks (clearly tongue-in-cheek but not interpreted as such by the world's media or the Cannes organisers) suggesting he sympathised with Hitler. We've promised the distributors not to talk too much about that today. That means there is a touch of Fawlty Towers about the encounter. You know not to mention the war... even if he is the one who wants to bring it up.

Putting the Cannes firestorm behind him, von Trier reveals he is already researching a new film, which has the working title, The Nymphomaniac, and is all about sex.

The project has its origins in a remark made to him by a cinematographer who warned him that, as he grows older, he shouldn't live up to the stereotype of priapic, leering older filmmakers and make movies in which the women grow younger – and nuder. True to form, von Trier took this as a challenge and decided that was exactly what he would do.

Von Tier doesn't like being told what to do. When the co-producers of Melancholia had the temerity to suggest he shorten the film, he immediately made it a few minutes longer. "Everyone has their two minutes of fame where they stand up and say this was not good. At a certain point, I [say] come on! I am 56 years old. I've been doing this [filmmaking] all my life. Do the film yourself, you fucking idiot! If you are so goddamn clever, why the fuck don't you do the film yourself?"

"It's certainly a real project," von Trier protests at the idea that The Nymphomaniac is a Russ Meyer-like joke. "I am talking to all the girls from when I was young who were screwing around like hell. It's so much fun. They talk for three hours. Even if the film, for some reason, doesn't come to be, I am having a fantastic time researching. Maybe it's not a good sign but I am really excited by this project."

The new feature will be about "the erotic life of a woman from the age of zero to the age of 50". As a self-professed "cultural radical", the director refuses to countenance making The Nymphomaniac without showing penetration. That, he confides, may worry the censors. "And I also have a problem with the sex that we all know is part of our lives before we are 18 years old. Let's see how I handle this. I don't intend to break any laws but it will be an interesting experience."

Von Trier adds that The Nymphomaniac was partly triggered by the fact that he recently "started reading books" again. When I spoke to him via Skype in February, he was immersed in Thomas Mann's Buddenbrooks (a story about the crumbling of a bourgeois family over several generations that clearly influenced Melancholia). Now, he is mid-way through the works of Proust.

In Search of Lost Time, von Trier notes, is full of sex, whether it's the decadent aristocrat Baron de Charlus preying on men or the narrator's erotic longing for Albertine. The Nymphomaniac is shaping up as a Proustian sex film. Von Trier is planning two versions: "what you would call a hardcore version – that doesn't mean it is a porn film, but that there is penetration – and a softcore version you will be able to show in other cinemas".

He has been meeting doctors and psychologists as well as nymphomaniacs and insists that the film will be about ideas as much as about sex.

"Basically, it's a film about sex and then there is a lot of talking, like in the books I am reading now. They talk and talk and talk, which I love. And there is a lot of philosophy. Hopefully, it will be a very messy film. That's what I am looking for, after reading these books. I'd like to make a film that has a lot of different diversions and strange ideas and little parts that have nothing to do with the storyline." He hopes to shoot next summer.

Meanwhile, his collaboration with Martin Scorsese on a documentary/experimental film along the lines of von Trier's 2003 film, The Five Obstructions, is also still expected to go ahead.

It's von Trier's misfortune that he emerged as a filmmaker at precisely the point that the old cult of the European art-house auteur was entering its death throes. By the time his films started being shown at the major European festivals in the late 1980s and early 1990s, the veneration once accorded to Andrei Tarkovsky, Michelangelo Antonioni, Bernardo Bertolucci, Ingmar Bergman et al, was fast fading. Von Trier has just about managed to keep alive the idea of the big-name European auteur, but has done so partly by whipping up scandal. He is the arch provocateur. With every new movie, there's bound to be a talking point: the genital mutilation in Antichrist, the computer-operated camera in The Boss of It All, the anti-Americanism of Dogville, the spats with Bjork during the making of Dancer in the Dark, the Dogme shock tactics in The Idiots etc, etc. His artistry is overlooked as he continues to be categorised as the ageing enfant terrible of European cinema.

The Danes themselves have an ambivalent attitude towards this maverick director in their midst. Melancholia hasn't done especially well at the Danish box-office. Industry insiders sometimes joke that if Danish TV audiences were given a choice between a von Trier movie or the test card, almost all would watch the test card. In recent years, he has been making his films abroad, in Sweden or in Germany, and with international casts. Even so, he is the figurehead of the great Danish film revival. His success internationally has opened up the way for other directors, such as Thomas Vinterberg and Susanne Bier (who won an Oscar this year for In a Better World).

As his business partner and producer Peter Aalbæk Jensen explains, von Trier is used to being disliked. When he and Jensen first started collaborating more than 20 years ago on Europa, "Lars was bankrupt because he had made this film called Epidemic. Everybody thought he was a loser and, on top of that, he had this unpleasant behaviour." Ask Jensen to elaborate and he replies: "He was a rude fucking bastard. We were two flops that united." Von Trier's working method was "to try to drive people nuts around him by teasing them constantly... He is absolutely a darling and I love him very much but he is also a monster."

On his couch in Filmbyen, von Trier seems placid enough. He is happy to reminisce about his childhood with parents who used to take him to nudist camps. "I don't have any sexual memories but I remember there was a little post office and you'd go in – and the post officer was only wearing a hat. If you were inside a tent and you put on a sweater because it was cold, when someone came to visit you had to get rid of the sweater straight away. You couldn't be caught being clothed. It was very peaceful... and fair."

Not that his childhood was especially idyllic. He was "very scared" when he was growing up. "I was brought up in a very free upbringing, but that could be seen as [the parents] not taking responsibility for your child in a way. Also, I went to a very firm school where they [the teachers] were hitting the children." The kids who were used to being beaten back home didn't have a problem with the discipline. Von Trier wasn't so fortunate. "For little Lars, who wasn't beaten back home, it was a terrible encounter. I was just thinking that the more civilised you grow up, the less fit you are to meet the world."

When he was an adult, von Trier made a startling discovery about his family background. His mother, Inger Horst, told him that Ulf Trier, the man he had always presumed was his father, wasn't his father. Little Lars had been conceived as a result of a fling Inger had had with her former boss, Fritz Michael Hartmann.

"I remember my first thought was – at last, something for the biography!" he jokes about this revelation. "[Ingmar] Bergman was put into closets and beaten as a child – which his sister later claimed was a lie. So I thought that was something."

In the wake of his discovery about his biological father, von Trier began to "look around his environment and think maybe they [the people around him] don't tell the truth. That was a revelation that started much of my creative life. It fitted quite well with that idea that everything is not as it seems."

When the director finally met his 'real' father, he didn't like him at all. The father didn't like him either. They met in an office. "He said that he thought my mother 'protected' herself. Secondly, he said, 'I never accepted that child'. And in the end, he said any connection should go through his lawyer. If you did expect some soap thing where we just hugged each other, it was not like that. I didn't like him from what he said. I didn't like his looks. I thought he was feminine. My mother had said that, 'I so hope when I am dead you will meet him because he is the most wonderful man in the world'. I didn't think so at all."

Hartmann had an artistic background, with several composers in his family. "My mother was indecent enough to say on her deathbed that I should be happy for that," von Trier sighs. "Fucking bitch. Yeah, OK. I am quite negative towards her, and the father who is not my father has a god-like status for me. After all this nonsense in Cannes, I am claiming that since he (Ulf Trier) was Jewish and gave me a cultural Jewish upbringing, I am as good a Jew as any. Maybe he didn't give the sperm but he gave me a family and a background."

Von Trier's descriptions of his complex domestic circumstances can't help but rekindle memories of Melancholia. After an opening montage showing the end of the world, the first half of the film is devoted to a prolonged wedding scene in which most of the relatives and guests behave atrociously. This is a big set-piece in the spirit of the wedding in The Deer Hunter ("one of my absolute favourites"). At one stage, the bride's super-caustic and cynical mother (Charlotte Rampling) gets up and pours scorn on the very idea of marriage. Yes, von Trier acknowledges, there are traces of his own mother in Rampling's character.

The second half of the film, in which the two sisters (played by Kirsten Dunst and Charlotte Gainsbourg) wait for doomsday to arrive, likewise has an autobiographical undertow. The two characters both share some of von Trier's traits. "The film is a little bit based on a fact that I learnt from my therapist that a melancholic person, in the event of a great catastrophe, would be much more calm than a normal person, who would typically panic."

He has likened Melancholia to the Titanic, "in the sense that everybody knows Titanic is going down. It is just the matter of how it is going down. There is not the matter of who will survive because nobody will survive."

His influence is as much German romanticism as it is Hollywood disaster epics. This is underlined by the Wagner music on the soundtrack, the lyrical treatment of landscape and, above all, the way he homes in on the emotions of the sisters. "There is more horror in seeing a face watching the end of the world than in showing it," he declares. The film draws heavily on his own experience of anxiety and depression.

We're so used to the idea of von Trier as the anguished child, railing against his mother and making startling discoveries about his father, that it is easy to forget he is a parent himself. The filmmaker has two sons in their early teens from his second, current, marriage, and two daughters (one of 16 and one of 23) from the first.

Ask about his approach to parenthood and he declares: "First of all, I lie, which is very important. When they say, 'Will I die tonight?' I say, 'I promise you will not die

tonight'." This, he points out, is a promise that his own mother never gave him.

On the day I interview him, von Trier can't hide his pride that Agnes, his oldest daughter, has made it into art school: "She did this without my help whatsoever".

Agnes clearly shares many of her father's artistic – and gynaecological – preoccupations. "What I am very proud of is that she is doing sculptures of cunts only. That is her speciality," von Trier states in a matter-of-fact way, as if it is only to be expected that his daughter should be obsessed by genitalia.

Part of Agnes's inspiration is the Danish version of the children's book Where's Wally?. "The work that got her into the school was called The Woman Crawls Up Her Own Vagina and Finds Wally. That suits me fine!"

Von Trier's brow furrows a little as he thinks back to Cannes and the scandal surrounding his now notorious press conference. He had asked not to do the conference, saying he much prefers being interviewed one to one. "Then, when I say I am a Nazi, you will ask me what I mean. Then, I would be safe and we would go into a discussion... I've always hated these press conferences. I feel like a stand-up comedian on a stage. I say a lot and nobody laughs. I feel that I have to deliver something."

The Danish director was stung that people thought he really was a Nazi or an anti-Semite. At the same time, he is fearful of political correctness and insists on a free and frank discussion of what constitutes anti-Semitism. Part of his problem, he suggests, is that he is "extremely bad" at talking about his own films. That's why he is in danger of heading up blind or dangerous alleys.

Von Trier remains a cinephile. He speaks with a sense of awe about the films of Kubrick or Tarkovsky. One movie he especially admires is Liliana Cavani's The Night Porter (1974), in which Dirk Bogarde's ex-Nazi officer and Charlotte Rampling's former concentration camp inmate meet in a Vienna hotel and rekindle their sadomasochistic relationship. In Paris once, he paid homage to Cavani when he realised she was staying nearby. "I ran to the flower market – in bare feet I remember. I took all the wild lilies I could get and ran to her door. She opened it and was extremely angry and lesbian. I said, 'Thank you for The Night Porter'. She took the flowers away from me, slammed the door and said, 'That commercial crap!'."

For many years, von Trier tried to make a documentary about the great Danish director Carl Dreyer (1889-1968). Dreyer is revered today as one of the masters of world cinema. However, at the end of his career, he was despised by colleagues and critics alike and seen as a foolish old man. The masochist in von Trier clearly identifies with Dreyer, a filmmaker who never compromised his vision even as his popularity ebbed.

"I am quite proud of some of the films I have done, yes I am," the director declares. "Am I afraid of being thought of as an old idiot, like Dreyer was? I hope I will be an old idiot! I need to do what is right for me. If that means I am an idiot in the eyes of the crew, critics and whatever, then it has to be that way."

'Melancholia' is released on 30 September