BERLIN, Germany — When “Swastika” was shown at the 1973 Cannes film festival, scuffles broke out and someone threw a chair at the screen.

“It was pandemonium,” said Philippe Mora, the documentary’s French-born, Los Angeles-based director. “People were shouting and throwing things. Eventually they stopped the film and a guy came out and said, ‘Ladies and gentlemen, this is the Cannes film festival, not a beer hall.’”

The reason for the furious reaction was that Mora’s documentary appeared to humanize Adolf Hitler. Using never-seen-before home movies of the Nazi leader relaxing at his mountain retreat at Obersalzburg, shot mostly by Hitler’s girlfriend Eva Braun, "Swastika" shattered the accepted portrayal of Hitler as inhuman.

Audiences got to see the personification of evil cuddling his dog, playing with children and discussing “Gone with the Wind.” They didn’t like it and the film was effectively blackballed in Germany.

Last month, Swastika was shown at Berlin’s Humboldt University to a new, mostly younger audience, who were among the first Germans to see the film. Not only did they refrain from throwing things, they felt comfortable enough to laugh at the bitingly ironic moments and asked polite questions during a Q-and-A session afterward.

It was an illustration, Mora noted later, showing that Germany’s view of its own Nazi history is constantly evolving and that key questions — including why so many ordinary Germans fell into line behind the regime that perpetrated the Holocaust — are still being answered.

Until the 1980s, West Germans barely discussed the Nazi era, said Simone Erpel, the co-curator of a ground-breaking new exhibition, “Hitler and the Germans,” part of the same urge to re-examine the Nazi era as the screening of "Swastika." The idea of Hitler as a movie character was taboo until the late 1990s. Controversial films such as “Downfall” (2004), which portrayed Hitler humanly and even at times sympathetically, or “Mein Fuehrer” (2007), which was a full-blown comedy, smashed that taboo.

“Philippe’s film was just too early,” Erpel said after the Humboldt University screening, at which she co-hosted the Q-and-A. “A lot has changed since the early '70s.”

Her current exhibition at the German Historical Museum, which shows how ordinary Germans enthusiastically contributed to the Nazis’ powerful propaganda machine, would have met a similar fate had it opened in 1973, she said.

“The Germans weren’t ready for those facts 30 years ago,” she said. “They had created legends that made a distinction between the German people and the Nazis. People would say, ‘My grandpa wasn’t a Nazi and he wasn’t a murderer.’”

The outrage that originally greeted "Swastika" was all the more heart-breaking because of the extraordinary lengths to which Mora went to uncover the Hitler home movies. It was the stuff of an international espionage novel.

He has since become a cult director of films such as “Mad Dog Morgan,” starring Dennis Hopper, “The Return of Captain Invincible,” starring Alan Arkin, and the Christopher Walken sci-fi film “Communion,” not to mention B-horror movies “The Howling,” parts II and III.

But when he began Swastika, Mora was just a 23-year-old documentary filmmaker exploring Nazi history. His own father, who was born in Leipzig, had been thrown out of Humboldt University in the 1930s because he was Jewish.

Mora had originally planned a biography of Albert Speer, the Nazi architect and Hitler confidant who escaped the death penalty. He spent a day at Speer’s home in Heidelberg, during which Speer played his own 1930s home movies. In one film, Eva Braun could be seen holding a movie camera at the Obersalzberg retreat, Berghof.

“I asked Speer, ‘Whatever happened to the footage from Eva Braun’s camera?' He said, ‘It doesn’t exist.’ But he was lying.”

A few weeks later, Mora said, his German creative partner, Lutz Becker, was at a party and met an American soldier who was among the first into Berghof at the end of the war. He asked the soldier whether they’d found any film and the soldier replied, “Yes, piles of it.”

Mora went to the Pentagon, where an officer told him they would look for the film. He never expected to hear from the officer again but three months later, the officer called. They had found the film.

“We were just dumbfounded,” Mora said, over lunch in Berlin last month. “Here was this incredible footage that’d just been sitting there because no one had asked for it.”

The product is a strange and unsettling film with no narration and only a vague storyline. Instead it works at a gut level. In his banal conversations with fellow Nazis at Obersalzberg, Hitler comes across as utterly human.

The next moment, the film cuts to newsreel footage of Hitler as a demigod in front of adoring crowds that, as Mora points out, could be “screaming fans at a Rolling Stones concert.”

As a viewer, one gets uncomfortable glimpses into how people got swept up in the euphoria. The film also has a sardonic humor. It ends with some of the most gruesome Holocaust footage the viewer is ever likely to see, only to roll the final credits with Noel Coward’s satirical song, “Don’t Let’s be Beastly to the Germans.”

Mora said he never meant to question Hitler’s evil or make light of the darkest period in German history but rather to make viewers think about it in different ways.

“The film was made under the assumption that everybody knew Hitler was a monster and a murderer. I didn’t realize it was open to debate,” he said. “But he was a man with a mother and a father and sisters and a pet dog. And that viscerally disturbed people.

“If you think of Hitler as coming from outer space or as a supernatural demon, you are not going to see the next one coming. But there probably will be another one.”

Jens Koethner Kaul, 46, a feature film producer who was at the Humboldt screening, thought "Swastika" should be made part of the high school curriculum in Germany.

“Growing up in Germany, you learn the facts of the Nazis and the Holocaust,” he said. “But the emotional understanding was missing. There was clearly something seductive or at least tempting about these guys that made people follow them. You get that from Philippe’s film.”

As Germany slowly digests its past, controversies will continue to arise. Perhaps the final frontier is humor — and according to Simone Erpel, that is on younger filmmakers’ radars.

“Ironic and satirical approaches are a way to deal with the past,” she said. “Laughing about a very serious thing is important. It’s how satire works. That will start happen in the next 10 years.”