For auteurs, the question sometimes becomes: How much do you believe in your film?

When actor Edward Norton worked with director Spike Lee on 2003’s “25th Hour,” he found a lot to admire about the filmmaker’s process. Already bowled over by seeing “Do the Right Thing” at age 18 — a film Lee had written, directed, starred in and produced — Norton couldn’t imagine how “25th” could be shot in 26 days.

“Nobody can do that,” says Norton, who has now written, directed, starred in and produced his own independent film, “Motherless Brooklyn.” “I never could have made this film on this budget and on this schedule if I hadn’t worked with Spike back then.”

Being inspired by film actors, directors and writers is easy. It’s all there on the big screen, in the finished project. But fewer aspirational filmmakers first think, “What I really wanna do is produce.” That particular job, which can cover an enormous range of organizational, financial and generally unsexy duties, is frequently invisible and thankless.

But without producers, films wouldn’t get made.

Director Rian Johnson

(Jay L. Clendenin / Los Angeles Times)

Perhaps that’s one of the reasons we’re seeing so many writer-directors also putting on producer hats this season. Films including “Marriage Story,” “The Report,” “Knives Out” and “Parasite” have all been made by filmmakers wearing three hats, while “Jojo Rabbit” and “Brooklyn” feature writer-director-actors who took on a producing role.

No surprise, they’re exhausted. “It’s a long, laborious process of rolling a boulder up a hill until it tips over the other side,” says “Knives Out” creator Rian Johnson, who took his first producer credit with the film.

Norton echoes that metaphor. “Writing is lonely; directing and acting, if you’re overlapping them, is challenging but fun. But producing is just pushing a rock up a hill. And sometimes it rolls over you on the way back down.”

Why anyone would put himself or herself through those additional rigors and headaches depends on the filmmaker. In many cases, the answer has to do with establishing or maintaining control of the project.

Writer/director Scott Z. Burns

(Ana Venegas / For The Times)

“This is ultimately a business, and by not engaging with that part you cede power to other people,” explains “Report” filmmaker Scott Z. Burns. “The tendency on the part of artists to shy away from the nuts and bolts part of the business doesn’t end up benefiting you in the long run.”

As a producer on “Parasite,” Bong Joon Ho had a say in virtually all aspects of the project he’d developed, written and directed: He hired co-writer Han Jin Won and the key crew, arranged the workflow for sound recording and editing, and was involved in key marketing decisions.

“There is a slight overlapping among producing, writing and directing,” he writes in an email. “The borders among these three processes aren’t always so clean cut and exact. I think it’s more advantageous for me in handling the overall film to cover a wider area.”

Discovering the need to produce may have come in an unplanned way for many filmmakers. Taika Waititi, the filmmaker behind “Jojo,” says that while making his early films in New Zealand he had to package a near-final project before showing it to the film commission to get financing. “That’s the only place you can get the financing, so you’re sort of forced to make do with whatever you get,” he says. “Even before I was a filmmaker, my friends and I were always making props and costumes. You had to do everything. To some degree it still feels like that there.”

“Marriage Story” filmmaker Noah Baumbach says being a producer taught him what kind of films he wanted to make. “I discovered what kind of environment will help me, the actors and the crew do their best work, while staying keenly aware of budget and the parameters budget will naturally create,” he says. “I discovered producing organically that way.”

Director Taika Waititi

(Kent Nishimura / Los Angeles Times)

Still, even multitasking writer-directors recognize that producing is not a one-person job. Many have regular producing partners, who filmmakers say are worth their weight in gold.

“Ram [Bergman] is the one who protects my process so when I need to disappear into the film I can, and his day-to-day producing on set lets me focus on the creative work of the day,” says Johnson.

“I get tunnel vision while directing,” says Waititi. “The producer is usually right next to me and is a bit like my mother. He looks after me, says, ‘You need to eat this’ — like a really good personal assistant.”

“If you have a great producing partner, then [self-producing] maybe isn’t as critical,” adds Burns. “Somebody you really trust and rely on frees your brain to do the work of the writer and director.”

Being a producer also introduces a whole new level of learning to director-writers, who may have previously thought they knew everything about how a movie gets made. “It really makes you appreciate what it has taken to bring the whole thing together,” says Johnson.

In fact, nobody says producing is ever going to be easy. “It’s the film business equivalent of if you want something done right, you have to do it yourself,” says Norton. “It’s a necessary grind to get to the fun part. And if you believe in your story, it’s what you have to do to put it all together.”