RELATIVITY THEORY FOR NEWLY MINTED FAMILY MAN ALBERT BROOKS, 'THE IN-LAWS' AND 'FINDING NEMO' HIT CLOSE TO HOME.

Byline: Bob Strauss Film Writer

A good father will do anything for the sake of his children.

He'll swim the deepest sea.

He'll fight anyone who threatens them, even if the villain has a nuclear-powered submarine, or is a dentist.

He'll wear a thong in public.

OK, so some of that stuff only Albert Brooks would do. But you get the paternal sacrifice angle, right?

``I have a 4-year-old boy and a 3-year-old girl,'' says the 55-year-old star of two very different new movie projects, a remake of the espionage comedy ``The In-Laws,'' opening Friday, and Pixar/Disney's computer animated underwater extravaganza ``Finding Nemo,'' which hits theaters a week later.

``I wouldn't have done either of these movies if I didn't have my family, I really wouldn't have. To have someone to come home to and talk to about the movie is everything to me. And certainly, the cartoon - as I graciously say, who would work for scale and no billing if you didn't have kids?''

While parenthood late in life has profoundly changed Brooks, the actor obviously maintains the caustic sense of humor that we know him for from decades of television appearances and the distinctively observant comedies - ``Real Life,'' ``Modern Romance,'' ``Lost in America,'' ``Defending Your Life,'' ``Mother'' and ``The Muse'' - he's written and directed.

But while Brooks' performances in other people's movies (such as Martin Scorsese's ``Taxi Driver,'' Steven Soderbergh's ``Out of Sight'' and James L. Brooks' ``Broadcast News,'' the latter of which earned no-relation Albert an Oscar nomination) have often struck more dramatic tones, he's rarely played a family man.

Chalk up the latest incarnations to the influence of his own first-and-only marriage of five years.

``Before I met my wife, I never thought about having children,'' says Brooks, who still marvels at how lucky he is to be married to wife Kimberly, a computer graphics designer, and to have little Jake and Claire running around the house. ``As a single man, I never wanted it, thought about it or anything. So the first step was to meet the woman that I would be willing to do anything for.

``And it's almost cliche to say, but you can't even imagine it. It's just something that's different. This love is a different love. And it's not only a love; you're seeing the worst part of you and the best part of you.''

Dads gone wild

Both sides of that are certainly evident in Jerry Peyser, the multiphobic, interfering Chicago podiatrist Brooks plays in ``The In-Laws.'' Following the basic contours of the 1979 comedy that starred Alan Arkin as a strait-laced dentist and Peter Falk as the undercover agent whose son is about to marry the medico's daughter, the new version finds Jerry being dragged, kvetching and screaming all the way, across half the world by his cavalier future in-law Steve Tobias (Michael Douglas). The mismatched duo eventually work together to break up a plan to sell a Russian nuclear submarine to a sexually confused French arms dealer (David Suchet's Jean-Pierre), all on the eve of their children's nuptials.

During which, Jerry teaches superspy Steve a lesson or two about good parenting.

``This had to be more about people, less about the things and the explosions,'' Brooks says of what distinguishes the two versions. ``I think Alan Arkin and I are different actors anyway, so all of those differences have got to show up. And I think that the relationship between Michael and I is way more than their relationship. I've heard somebody say that they were like a vaudeville act, and we're more like, these two guys.''

Not that the film doesn't have its share of broad laughs - none bigger than when Jerry, forced to distract the smitten Jean-Pierre while Steve sets up his sting, emerges from a hot tub wearing nothing but a bathing costume of the nasty Frenchman's choosing.

``I have done, for the last four years, treadmill every day of my life,'' Brooks wants us to know. ``So when I knew I had to do this, I set the incline 5 percent higher.''

Bada bump. But seriously, folks ...

``The big laugh in this movie, when I get out of that hot tub, is not because I'm showing my butt,'' Brooks insists. ``It's because that podiatrist had to get into that bathing suit. Those laughs have to be character laughs.

``But I had trepidation,'' he admits, ``only because I thought that if I die and the word 'thong' appears in the first or second sentence of my obituary, I've really miscalculated everything.''

According to his collaborators, miscalculating a joke is essentially a congenital impossibility for Brooks. He is, after all, the son of a noted radio comedian, Harry Einstein (listeners knew him as Parkyakarkus), and brother of ``Super Dave Osbourne'' portrayer Bob Einstein. L.A. native Albert - who legally changed his last name for obvious reasons - has been honing his craft since he began doing TV stand-up for the likes of Steve Allen, Dean Martin and Ed Sullivan in the late 1960s. He started directing short films in the early '70s; such projects later became a mainstay on the initial seasons of ``Saturday Night Live.''

``Here's a news flash: Albert's funny,'' says ``In-Laws'' director Andrew Fleming (``Dick''). ``But he's also, actually, very focused, and then sometimes he lets loose. When he relaxes, it's basically like watching him do routines on 'The Tonight Show,' and everybody on the set just stops and listens. He's like a comedy machine.''

Douglas adds, ``I was so grateful and happy that Albert, who's pretty picky whenever he steps outside of his own stuff, agreed to do it.''

He took the bait

Indeed. Brooks admits that he had to be convinced to provide the voice tracks for ``Nemo,'' in which he plays Marlin, a frazzled clownfish who travels thousands of miles to rescue his only son from the aquarium of a scuba-diving Australian dentist.

``The two words that make it impossible to say no are 'Pixar underwater,' '' Brooks admits. But the comedian, who considers himself an actor first and foremost, needed further inducements to commit to several years of sporadic, solitary dialogue recording. So the Pixar folks, whose films include the ``Toy Stories'' and ``Monsters, Inc.,'' specially animated a bit of footage just to woo him. In it, Marlin delivers a monologue from Brooks' ``Defending Your Life.''

``So I'm sitting there watching this fish go, 'So I didn't make enough money! So call me a hippie, send me to hell!' How could I not say all right, I'll do it?''

Still, besides the remuneration caveat already voiced, there remained a deeper reason for Brooks' trepidation that only got worse once work commenced.

``I didn't want to do it because it took me an hour after each recording session to forget about it, to not imagine, God forbid, if something happened to one of my children,'' the actor admits.

Which is understandable. But also sounds a little, well, neurotic, too. Brooks does not like that word applied to him or his work ... nor any other comparison, for that matter, to the work or persona of Woody Allen.

``I think that how that got started was, there are so few people who started as a stand-up and went on to make their own movies,'' Brooks reckons. ``Woody was certainly the godfather of that, and then I was a little bit later, and the only one doing it from here. Y'know, people always go to the easiest thing they can attach you to, so I became the West Coast Woody Allen.

``And the other thing is that word 'neurotic.' But my answer to that is that there is no comedian in the history of movies that wouldn't be neurotic. I mean, W.C. Fields was neurotic; he was an alcoholic. Charlie Chaplin - I don't know what you'd call the Little Tramp, but he certainly wasn't like anyone I've ever met. You wouldn't make a comedy with somebody who was the most normal guy in the world, because what would you do with that?''

Although Brooks is writing the script for the next film he plans to direct, he says he's more interested at the moment in widening his acting options - for one reason, to further undercut the Woody comparisons.

``I think that the more I can act in other people's movies, the more that will go away,'' Brooks says with a shrug. ``The one thing Woody Allen hasn't really done much is been an actor-for-hire. I mean, Woody Allen didn't do 'Broadcast News' or 'Out of Sight.' ''

There's a better reason to work as much as he can now, though. And it's just the opposite from when he was starting out.

``Y'know, to have a career in show business - especially in comedy, when in the early years you're on the road and doing three shows a night - you're kidding yourself if you think that you can have a successful relationship,'' the family man notes. ``You're the most selfish person on the planet or you can't succeed, because if you're not thinking of what you're going to do tomorrow, then nobody's going to care. I had so many years of that, I just got sick of myself and didn't want to do it anymore.

``So now I have these people I love. I also have these private-school bills ... Y'know, all kinds of good things motivate me to get off of my ass.''

CAPTION(S):

3 photos

Photo:

(1 -- 2 -- cover -- color) Other fish to fry

Albert Brooks works for scale in `Finding Nemo' and for richer and poorer in `The In-Laws' - but fatherhood has been pricesless

(2) ``I have a 4-year-old boy and a 3-year-old girl. I wouldn't have done either of these movies if I didn't have my family, I really wouldn't have,'' says actor and family man Albert Brooks.

(3) ``So I'm sitting there watching this fish go, 'So I didn't make enough money!' ... How could I not say, 'All right, I'll do it.'?''