"I have never talked about that," Diesel says quietly.

In conversation at his bungalow on the Burbank Universal Pictures studio lot, the granite-tough star seems genuinely taken aback, uncharacteristically humbled, to be opening up about his own fallibility.

"I will never be able to convey the anxiety, the frustration, the fear that I was feeling before making this movie when the funding wasn't getting to where it needed to get," he says. "To where padlocks were being put on the production studio in Canada because we had insufficient funds to get going. To where I had to leverage my house."

At stake: the independent production he spent years putting together as a producer was in jeopardy of shutting down. Rather than wait for an insurance company to bond the $34-million sci-fi film in order to secure a key bank loan, the star took matters into his own hands. Risking foreclosure on his own home, he provided the financial backing for "Riddick" himself until bank funds came through.

"He had personal financial exposure when he didn't plan on being that involved," the movie's writer-director David Twohyconfirms. "Vin reached into his own pocket to make sure the crew didn't go home. He was putting his money where his mouth is."

Which is to say that Diesel's sweat equity on movie projects these days doesn't necessarily end with bench presses and power squats.

The star (government name: Mark Sinclair Vincent) may have become associated with crazy stunts, blunt-force trauma and sequel after blockbuster-grossing sequel (cumulative worldwide gross for the "Fast & Furious" installments in which he's featured: $2.14 billion) — a certain cinema of gigantism. But a closer inspection of Diesel's involvement as a producer for "Riddick" and the last three "Fast" movies reveals that his creative control extends to overhauling scripts, casting (sometimes dictated by his Facebook page's 46 million "friends") and even personally hawking international film distribution rights.

"What people are often shocked to hear is that I work more and harder when I'm not filming a movie than when I am," Diesel says from his perch behind an office desk.

With the exception of a costarring role as an extraterrestrial plant monster named Groot in Marvel Studios' upcoming comic book adaptation "Guardians of the Galaxy," all Diesel's acting efforts stretching into the foreseeable future arrive with producer credits attached.

Among them, a big-screen blowup of the 1970s TV show "Kojak"; a sequel to 2002's "XXX," "XXX: The Return of Xander Cage"; the hunter-turned-hunted thriller "World's Most Wanted," and the actor's long-gestating dream project: the historical biopic "Hannibal the Conqueror."

At the root of his current status is what Diesel not-so-humbly refers to as "probably one of the best deals in Hollywood history": trading a walk-on cameo in 2006's "The Fast and the Furious: Tokyo Drift" for a chance to reboot "Riddick."

Portraying antihero Richard Riddick in the low-budget thriller "Pitch Black" was the actor's Hollywood breakthrough. Before that film became a cultishly popular sleeper hit, he was known for supporting roles in the dramas "Saving Private Ryan" (1998) and "Boiler Room" (2000), and to a lesser degree for having premiered his debut feature as a director, "Strays" (1997), at the Sundance Film Festival.

The last time multiplex audiences saw Diesel's escaped convict character in "The Chronicles of Riddick," however, things didn't turn out as planned. Universal's $105-million sci-fi "Pitch Black" sequel fizzled at the box office, taking in just $57 million domestically and effectively derailing the franchise's future prospects.

"I had initially asked the studio if I could pay them $10 million to get the rights for 'Riddick' — to put my houses up and borrow some money," Diesel recalls. "At that time, I felt like 'Riddick' was held in a vault. We weren't allowed to be creative with that project we had already fallen in love with. They said, 'We couldn't bear the idea of this movie being successful somewhere else. So the answer is no.'"