The day’s light was fading, but the cast and crew of “Thor” were making good headway on a battle scene — a giant, fire-breathing alien automaton was laying waste to a tiny desert town. Still, director Kenneth Branagh kept glancing at the horizon with anxious Irish eyes. The Marvel Studios and Paramount production already had been battered by windstorms, and on that April day last year, Branagh feared another tempest was on the way.

Sure enough, a few minutes later, Branagh’s team was in a mad scramble to save lighting gear, cast chairs, script sides, props and their own eyesight from the winds barreling through the main drag of their faux city, which recalled both old Edward Hopper paintings and young Dennis Hopper films.

Later, Branagh, whose crew also dealt with rain, frigid nights and mud, was sanguine about the elements. “Well, we are making a movie about the god of thunder.”

“Thor,” a mash-up of old gods and costumed heroes, opens May 6 with Chris Hemsworth in the title role; newly minted Oscar winner Natalie Portman plays Thor’s mortal love interest, Jane Foster; Anthony Hopkins is Odin, the king of Asgard and Thor’s father; and Tom Hiddleston is Loki, the trickster god and Thor’s conniving brother. Although the legend dates to Norse mythology, which at times has presented the character as a ginger-bearded warrior wearing iron gloves and traveling by goat-drawn carriage, you won’t be seeing that Thor in this film, which instead follows the sleeker, four-color mythology set down in the pages of Marvel Comics beginning in summer 1962.It’s not especially surprising to see art-house souls migrate to expensive superhero films — “Eternal Sunshine of the Spotless Mind” director Michel Gondry took a ride with “The Green Hornet,” and Christopher Nolan made his mark with “Memento” long before he went to Gotham City — but Marvel Studios President Kevin Feige was still taken aback a few years ago when Branagh’s camp inquired about “Thor.” Feige, whose passions run more toward “Star Trek”than “Masterpiece Theatre,” was immediately intrigued, because he had once (reluctantly) sat through Branagh’s adaptation of “Much Ado About Nothing” and had been stunned by how much he enjoyed it. “The accessibility of it,” Feige said of the vibrant 1993 comedy, “that makes him the perfect guy to take Thor to the screen.”

Those comics by Jack Kirby, Stan Lee, Roy Thomas, John Buscema  and others made it into the hands of young Branagh. When he was growing up first in Belfast, Northern Ireland, and then in Reading, England, American superheroes were a bit of a mystery, with the exception of the blond-tressed thunder god who wore a winged hat and a red cape. “I was passionate about Thor,” Branagh, 50, said wistfully. “There was so much there, this hero with primitive brute strength and the dysfunctional family and always this sense of epic about it, the journeys and quests and vendettas.”

Branagh made his mark with “Henry V” onstage. He then took the role to the screen in 1989 and earned Oscar nominations for acting and directing. He directed six additional feature films over the next seven years, including “Dead Again” and “Hamlet,” but the critics weren’t always kind. Branagh began turning down Hollywood movies in favor of stage projects where he could take his risks with live audiences instead of studio executives.In hindsight, the tales of royal intrigue, clanging metal and sibling betrayal were the perfect training wheels for the youngster who would become one of his generation’s signature figures of the Shakespearean stage, exhibiting, according to the London Standard, the “vitality of Olivier, the passion of Gielgud, the assurance of Guinness.”

In recent years, Branagh has focused on his role as a producer and title star of“Wallander,” the well-regarded British TV series based on Henning Mankell’s novels. He also costarred in Bryan Singer’s 2008 film “Valkyrie,” a movie that was respected more than enjoyed, and he produced and directed the 2007 films “Sleuth” and “As You Like It,” both of which fell flat.

Against that backdrop, “Thor” is a chance to hammer out a new start. It gives him the largest budget of his career ($150 million), his first experience with 3-D (“It’s interesting to find yourself excited creatively about inter-axial distance,” he mused) and a chance to win over genre audiences let down by his “Mary Shelley’s Frankenstein,” the 1994 film starring Robert De Niro that looked so good on paper and so muddled on the screen.

Still, on the “Thor” set, Branagh (and Hopkins) were a bit like titans walking among the younger mortals of the cast.

“You could be in awe of Ken, but he’s such a nice guy that he puts you at ease,” said the 27-year-old Hemsworth. “He has such a plan and so much attention to detail. There aren’t many people who have so many ideas about character and background and subtext. To talk to him about kings and sons and empires.”

Portman made it clear that she signed on to make a Branagh film, not a “Thor” movie. “There was no script when I signed on,” she said. “I just had faith that I was going to be working with him as the guiding hand. As a kid, I had no focus for Shakespeare movies, but I still found myself watching ‘Much Ado About Nothing’ over and over. He has such an understanding of dramatic structure and text analysis, even when you’re working on something that is not Shakespeare.”A week after Hemsworth got the role, the filmmaker handed him the St. Crispin’s Day monologue from “Henry V” and told him to return the next day ready to do it on-camera, an exercise for pinning down Thor’s formal cadences. “I nearly had a heart attack,” Hemsworth moaned. “You want to do your best for Ken, he brings that out.”

Stellan Skarsgård, the veteran actor who plays a scientist who befriends Thor, noted that Branagh’s stage and film work as an actor make him a more adept director.

“It’s definitely helpful to have a director who is also an actor, as long as he’s a good director, too, and Ken is a good director,” Skarsgård said. “You work with some directors who are afraid of actors. They don’t what to use them for really, all they are is bodies moving around in their images. Ken is very different. He knows when an actor is uncomfortable… His take on this kind of movie is he wants to bring authentic psychology to the characters so they become three-dimensional human beings in this big fantasy film.”

There’s no excuse if “Thor” isn’t tightly stitched together. Because of schedule switches in the Marvel release schedule, Branagh has been working on the project for almost three years. The film (which pulls strongly from the recent comics by J. Michael Straczynski, who has a story credit) presents Thor on the eve of his ascension to Asgard’s throne. His hubris leads to a dangerous misadventure against some ancient enemies, the Frost Giants, and his banishment to Earth. Dejected and stripped of his powers, he meets Foster, a scientist who has missed much of her own life while staring at heavens. Meanwhile, back in Asgard, Loki plots to take the throne.

The film premiered last week in Australia, and the reviews have been perhaps more polite than passionate. Richard Kuipers in Variety, for instance, wrote: “Neither the star pupil nor the dunce of the Marvel superhero-to-screen class, ‘Thor’ delivers the goods so long as butt is being kicked and family conflict is playing out in celestial dimensions.”

The challenge for the movie is kicking off a summer season crowded with superheroes; also, its anachronistic qualities aren’t as immediately accessible to teen audiences as, say, the wisecracking billionaire in “Iron Man.” Branagh nodded and said he would have to bring something old and something new to this marriage of antiquity and popcorn film.

“It is precisely that, both a challenge and an opportunity,” he said. “Gods amongst men is a well-traveled path in drama and storytelling, and it can yield dramatic, romantic and comic tension. We are presented here with this dynastic drama and all of the energy and imagination from the comic books. For us, story is above all and the creation of these two worlds — our Earth and Asgard — and presenting a ripping adventure. If you have a strong story or even a great story — I hope and believe that we can reveal that — the special effects and all the rest are layers that add to it.”

Branagh wiped a considerable amount of New Mexico dust from his forehead as he headed for his trailer after a long afternoon of explosions that had left his eyes red and weary. Asked what he loves about Thor, he smiled. The man who played Hamlet (and, in a wry twist, will playLaurence Olivier in “My Week With Marilyn”) didn’t cite character psychology. “When I was a kid, that name was just so great. Thor. You just know that’s the guy you want to go on an adventure with.”

– Geoff Boucher