Paul Mazursky knows of what he speaks in his new film "Down and Out in Beverly Hills."

"I've lived in Beverly Hills for a decade, and when you walk around, you see only gardeners. No other people. I figure there was a quiet nuclear attack here and the gardeners were the only ones with protective shields," Mazursky said in a recent phone interview.

Though conceding that "plenty of wonderful people live in Beverly Hills," Mazursky wanted to make a film "that made fun of how we all live here." He thinks Beverly Hills has been pretty much exempt from satire in the movies, except for passing nods in such films as Woody Allen's "Annie Hall." One day, in conversation with his writing partner Leon Capetanos (they wrote Mazursky's "Tempest" and "Moscow on the Hudson" together), Mazursky "got this flash."

"What would happen if a bum tried to drown himself in one of our swimming pools? I saw Renoir's 'Boudu Saved From Drowning' [1932] in the '50s and forgot it, and then again in the '60s and forgot it again. But I remembered that it was about an angry bum who tried to drown himself in the Seine, and when he was rescued he wasn't at all grateful. I thought we might import the story to Beverly Hills, and that, geez, it might work," Mazursky said.

After that flash came the inevitable chill. Mazursky said he and Capetanos were "immediately challenged by a whole set of realities."

"When you get an idea it sounds great -- for the first act. But we had to make this real. In the '30s, it was romantic in Europe to be a bum, a vagabond. There's nothing very romantic about it now. So we decided to make the family the bum happens upon a bunch of checkbook liberals who believe they're doing good to humanity with their money. We decided to make the household crazy -- a crazy dog, a politicized maid, a son who isn't sure what sex he is, and so on," Mazursky said.

If anything, Mazursky's film calls attention in an unsentimental way to the growing problems of the homeless in the United States. Mazursky wants the movie to shed a bit of light on the people who live in prosperity's shadow.

"I hope it does. I set out to make a real funny movie. I set out to get people laughing, and at the preview screenings I'm hearing laughter in the theater like I haven't heard since 'Bob & Carol & Ted & Alice' [1969]. Laughter can sometimes get you in touch with issues in a way nothing else can.

"Because the problem of homeless people is awesome, terrible -- and it's growing. The problem is that the homeless have been relatively invisible until recently. Oh, you'd see a bag lady or a bum occasionally, but nothing like now. Many of these people should be hospitalized, of course. But there's a group that got out there in the last couple of years who are not mentally ill. Like a guy who's lost his job, and the unemployment runs out, and he finds himself eventually living out of the back of an old station wagon. That's the day things get scary.

"I met a lot of homeless people in doing research for the film, and they have stories to tell. Once you get out on the street, and when you look for work you give your address as a city mission, you haven't much chance of getting the job. You're stuck," Mazursky said.

The character of Jerry, the street person who tries to end it all in wire-hanger magnate Dave Whiteman's swimming pool, is not a completely made-up character, Mazursky said. Jerry's combination of absolute poverty and an abundance of unexpected skills gives him his charm and accounts for why he is so seductive to everyone in the Whiteman clan.

"Jerry's definitely smart and a little sociopathic. Maybe he got on the streets in hard times when he simply couldn't cut it. Maybe he got tired of playing a losing game. I hate to be simplistic about it, but there's a lot to Jerry. He plays the piano pretty well, and he gives a great massage. He's very shrewd, certainly," Mazursky said.

The character of Jerry is played by Nick Nolte, whom Mazursky considers a "wonderful American actor who has done a lot of interesting work that has been undervalued." Nolte has developed the reputation of being hard to work with, but then again, all three of the principals in "Down and Out" have had much-publicized drug and alcohol problems. Richard Dreyfuss and Bette Midler are not known for being a director's day at the beach, either.

"I was warned about all three of them before I cast the film. 'You're going to have a nightmare,' I was told by a number of people. And yet there were no problems. Nothing great to report. They were all sharing and funny with just the normal amount of actor's anxiety about what they were doing. I think I caught them all at a good time," Mazursky said.

Mazursky's film-making style is becoming progressively more distinctive. It would be difficult to mistake a Mazursky movie for one made by any other director. But he gets a great deal of advice and many suggestions from others when making a film, he said.

"I do the following. I have a very open thing with the studio before making the movie. They are in on the casting, and we talk about the writing and so forth. My producers, Pato Guzman and Jeff Taylor, criticize me. 'Tell me anything you want to tell me,' I tell them. I've told my cameraman, 'Open your mouth if it's boring.' But at a certain point, there's only one voice heard," Mazursky said.