“Pina,” opening Feb. 3, isn’t the film Wim Wenders wanted to make. The German director had intended to team up with longtime friend and choreographer Pina Bausch to make a 3-D documentary about her dance company, the Tanztheater Wuppertal.

“We would have traveled to Southeast Asia and South America — it would have been much more of a road movie,” Wenders says. However, shortly before filming was to start, Bausch died suddenly. The movie became a eulogy, in part to their unlikely friendship.

When Wenders — best known for 1987’s “Wings of Desire” — first saw Bausch’s work, “It changed my life,” he recalls. “I became very emotional.”

They often discussed making a film, but Wenders had reservations. “My craft lacked something essential. Translating [dance] to screen, it seemed to be too much of a loss, so I was stalling for time. Each time we met, she asked, ‘Do you think we can do it soon?’”

What Wenders was looking for, he now realizes, was fully developed 3-D film technology. When he saw the 2008 concert film “U2 3D,” he realized that the capability was almost there. But there were still problems: “You couldn’t just rent a 3-D rig,” he explains. “The only ones that existed were prototypes. And nobody knew much about how to shoot in 3-D. I couldn’t call James Cameron [who was working on ‘Avatar’ at the time] and say, ‘Hey, how is this working?’ It was all very much pioneering, learning by doing.”

The 3-D in “Pina” (which earned an Oscar nomination this week for best documentary feature) is no mere gimmick: It creates a depth that mimics the feel of live dance. But during filming, Wenders had to fight the idea that 3-D had no place in an art-house film. “It took awhile until it sank in that this was a whole revolution in cinema, and, eventually, would be a language that almost everyone could use in filmmaking,” he says.

Now, 2-D “would feel like going back to an ancient form,” Wenders says. “I’m determined to work both in documentary and narrative film in 3-D. There’s so much to be discovered.”