As the whistles of clattering freight trains screech and howl in the distance, sounding all eerie-crazy-sad and half-demented with loneliness, Rob Nilsson, filmmaker and cinematic philosopher, leads a tour of his cottage-sized home and work studio in Berkeley. The place is ornamented with posters from his various films: Chalk, Stroke, Noise, Need, Attitude, Security and Winter Oranges.

A makeshift screening room, complete with wall-mounted movie screen and projection system, has been built in the room that doubles as a living room and kitchen. Upstairs is Nilsson’s editing area, where computers and monitors and all kinds of gleaming filmic machinery sit, and where work is being completed on his two newest films, Opening and Pan, both of which will be screening this week at the 29th annual Mill Valley Film Festival (MVFF).

The new films and two others Nilsson merely appears in–Bob Zagone’s Berkeley-based bookstore fantasy Read You Like a Book and Judy Irola’s Marxist-artist documentary Cine Manifest–will be sharing festival screen time with such high-profile films as the Polish Brothers’ Astronaut Farmer, Anthony Minghella’s Breaking and Entering, Philip Noyce’s Catch a Fire, Amy Glazer’s Drifting Elegant, Stephen Frear’s The Queen and Todd Field’s Little Children. The star power includes Sandra Bullock’s Infamous, Cate Blanchett and Brad Pitt’s Babel, Heath Ledger’s Candy, Famke Jansen’s The Treatment, and special appearances by the likes of Sydney Pollack, Forest Whitaker, Tim Robbins, Helen Mirren and Billy Bob Thornton.

The festival has been good to Nilsson over the years, having screened every movie he’s made since 1979’s Northern Lights. “I guess [the film festival] is a glutton for punishment,” Nilsson laughs, taking a seat on the sofa in his screening/living room. “There’s never been a film of mine that they’ve turned down, which I’m deeply appreciative of–and usually a bit surprised by.”

In many ways, Nilsson is the purest example of what the Mill Valley Film Festival has always striven to highlight: the power of individual filmmakers who take brave stances and make risky choices in order to make honest, unusual films that are strictly outside the mainstream. While the MVFF has gradually inched closer to big Hollywood films and the big-name star appearances, it has never strayed from the mission of giving ample screen time to films and filmmakers whose work, much like the groundbreaking recent films of the legendarily maverick Nilsson, might not otherwise be seen in a theater.

Nilsson first achieved acclaim with his 1979 black-and-white drama Northern Lights, about a 1915 standoff between a farmer and the U.S. government. That film won the Camera d’Or Prize at the Cannes Film Festival, securing Nilsson’s position as a visionary director with a decidedly “outsider” view toward filmmaking.

Over the next decade, Nilsson produced a number of similarly low-budget films, further developing his own improvisational, video-to-film moviemaking style. Best known are 1983’s mesmerizing taxicab fantasia Signal 7; 1986’s marathon-racing drama On the Edge (starring Bruce Dern and based loosely on the annual Mill Valley to Stinson Dipsea race); and 1987’s Heat and Sunlight, an edgy examination of love, jealousy and obsession which won the Sundance Grand Jury Prize.

While many filmmakers might have used their expanding reputation to go fishing for Hollywood contracts and bigger budgets, Nilsson astonishingly took a page from his friend John Cassavetes and elected to go in the opposite direction. In the late 1980s, he established the Tenderloin Y Group, a collective of nonprofessional actors and technicians, most of them found on the streets of San Francisco and Berkeley.

While editing a film in San Francisco’s Tenderloin district, Nilsson found himself wondering about the lives and struggles of the rough-hewn characters he encountered every day, people he warmly categorizes as “the shopping-bag ladies, the cart pushers, the screamers, declaimers and street-corner philosophers.” Says Nilsson, “Everybody has genius in them as long as you can find those people in their relaxed and natural state.”

With his directorial admonition to “be triumphantly yourself,” Nilsson has shown a knack for drawing profoundly natural and unstudied performances from his actors, most of whom have never acted before. Nilsson’s movies are not made so much as they are gathered, culled from the angry, shadowy, steaming streets of the city.

He calls his process “jazz cinema,” or more commonly “direct action,” because it requires his cast and crew to improvise, placing themselves directly in the middle of the action, launching real-life, off-the-cuff adventures in the dark alleys of San Francisco when no one knows they are there, or down by the railroad tracks of Berkeley, as in Pan (screening Sunday, Oct. 8), a film that makes heartrending visual poetry out of the iconic images of trains and railroad tracks.

Beginning with the film Stroke, Nilsson and his collective have enjoyed a fruitful 18-year collaboration, producing a string of remarkable films, including what he calls the 9@Night Films. The series will eventually total nine films, all telling loosely structured, improvisational stories that begin at the hour of 9pm, featuring 40 to 50 characters living on the edges of society.

Pan, about a fatherly street person and his unlikely friendship with a middle-class boy, is number seven in the series. The two remaining films, Used and Go Together, have already been shot but are still in rough-cut form. Of the first seven, all but one, Attitude, which premiered in Hong Kong, had their world premieres at the MVFF, where a new 9@Night film is always received with high expectation and an aura of defiant celebration.

While working on the 9@Night series, Nilsson has also been creating the Direct Action World Cinema series, five films created with that same grass-roots, improvisational style and filmed in various locations around the world: Japan, Jordan, South Africa and Berkeley. The latest in the series, Opening–about an art show opening in Kansas City and the tornado that changes the lives of the artists and poseurs in attendance–is also playing at this year’s festival (Friday, Oct. 6).

“I feel that these films are visionary works,” Nilsson says, “not because I did them, but because they come out of people who have never considered themselves actors or shooters or technicians, but who have a kind of an impulse, an idea about getting at least one look, from a fictional standpoint, at an area of the world people seldom see or want to see, and the people who populate that world.”

Asked to explain his process of beginning a film, and his strategy for developing a new project, Nilsson pauses. “When I start making a film, I don’t know what it is I want,” he says. “Honestly. I find what I want through the process of making the film. Or more truthfully, I use the process of filmmaking to pull out of me what it is I didn’t know I wanted to express.” Not surprisingly, the average filmgoer doesn’t always know what to think of his finished films because, in Nilsson’s words, “They don’t know what it is I’m expecting of them.”

And just what is it that Nilsson expects of his audiences?

“I’m expecting them to be adventurous,” he laughs. “First of all, if what they want is a traditional story, then they should go to a storybook. I’m not a storyteller. The stories have all been told already. What I’m doing is creating circumstances for characters to respond within, and then with my camera, I am building accounts of those actions in ways that move me–and that hopefully will move an audience.”

Now that his quest to complete all nine Tenderloin films is almost completed, Nilsson is beginning to feel his way toward his next decidedly nonmainstream project.

“I want to make 10 films about love,” he laughs. “And why do I want do that? I don’t know. Why does a poet write a poem? Because the poem appears. Why did I cast all of these street people in my films? Because they showed up. So I don’t know why I want to make 10 films about love–but I know I’ll be finding out once I start making them.”

The Mill Valley Film Festival runs Thursday-Sunday, Oct. 5-15. For the full line-up of films and events, visit www.mvff.com. To find out more about Rob Nilsson, visit www.robnilsson.com.