Dustin Hoffman shuddered. The screening room projector flickered with "rushes" of his first day's work in "Rain Man." Fighting off nausea, Hoffman knew his portrayal of an autistic man stank.

"It was death," Hoffman recalled in an interview with The Associated Press. "It was the worst work I had ever done. I said, `I can't do it.' " Defeated, the Academy Award-winning actor suggested the producers try Richard Dreyfuss instead.Hoffman, whose past triumphs include playing a woman in "Tootsie," was stumped by the part of Raymond Babbitt, a middle-aged autistic savant.

In "Rain Man," which opened earlier this month, the long-institutionalized Raymond is largely incapable of basic human emotions and speech but gifted with superior mathematical and memorization skills.

It's not an easy part. Having researched autism so intensively he was buried in documents and videocassettes, Hoffman, 51, had to dump his notes and observations in his dressing room and, well, act. No plot contrivances offered shelter.

As Hoffman tells it, all he could manage at first was a mishmash of his past work, mixing bits of the timid, near-sighted prisoner Louis in 1973's "Papillon" and the sickly Ratzo Rizzo in "Midnight Cowboy" from 1969.

Then, three weeks into filming, Hoffman and co-star Tom Cruise were driving down a bleak highway near tiny Cogar, Okla. The temperature, over 100 degrees, was matched by the humidity. In a sweat-laced improvisation, Hoffman started talking about how much Raymond missed his Hanes underwear. And he just wouldn't stop.

With those cotton briefs, Hoffman figured it all out.

"It looked like to me that you could have talked about your underwear forever," Hoffman said Levinson told him. "And I suddenly realized that yes, this character is in the now, and he is nowhere if he's not in the now.

"And I suddenly realized that I was playing off myself because I know something about obsession and I'm comfortable being obsessive. The rest of it just took care of itself."

"Rain Man" tracks Raymond's brother, Charlie (Cruise), a coldhearted schemer whose father dies, leaving him none of the riches he so desperately wishes to inherit. Instead, the $3 million falls into a mysterious trust account, which Charlie discovers benefits a brother he never knew he had.

In an attempt to filch the inheritance and save his bankruptcy-bound car business, Charlie abducts his newfound brother, and the two set out cross-country, top down, in a 1949 Buick Roadmaster convertible, their father's car.

In a series of minor incidents along the way, the brothers reach a remote, though improved, understanding of kinship. There are no triumphant scenes of blissful revelation. "Rain Man," whose title comes from Charlie's earliest, dreamy recollections of a shared childhood with Raymond, ends quietly. Some might say, indifferently.

"Rain Man" survived not only Hoffman's panic but also a year of screenplay revisions, the replacement of three directors, the scriptwriters strike and the meddlings of various entertainment industry know-it-alls. It emerges as a modest exploration of greed, communication and familial understanding.

"I didn't think an easy ending was the right way to go," said Barry Levinson, the movie's fourth and final director. "There had been a bunch of endings where (the brothers) were going to live happily ever after, but it didn't seem to apply."

Added producer Mark Johnson: "What we ended up with was much more simple than anything else that existed (in the scripts) before."

It was precisely that intended lack of ornament that proved so elusive.

Martin Brest ("Midnight Run"), Steven Spielberg ("E.T. the Extra-Terrestrial") and Sydney Pollack ("Tootsie") all were in line to direct "Rain Man" at one point or another. For a variety of reasons - some personal, some professional - the three came and went. But all wanted to dress the story up.

One script called for gangsters and FBI agents. Another suggested a big snowstorm. The role of Charlie's girlfriend (played by Valeria Golino) was either too big or not big enough. Raymond should be more "retarded." Or maybe not retarded at all. Perhaps Raymond and Charlie could become really close at the end? said some. Perhaps not, responded others.

"They (the assorted kibitzers) felt that there had to be a jeopardy in the story," Hoffman said. "In other words, `What's going to hold an audience if there's just two schmucks in a car?' "

Levinson, the director of "Good Morning Vietnam" and "Diner," suspected the audience could be held by just letting the schmucks be schmucks. The final script, turned in by Ronald Bass just as the five-month Writers Guild of America strike began, cut most of what Levinson considered superfluous.

"I basically wanted to get it down to a conflict between two people on the road," Levinson said. "More and more of what we see in the movies are mechanical plots. We pump them up instead of saying, `Let's just deal with the people.' "

Levinson's previous films have been marked by loosely organized stories, and in "Rain Man" he predictably chose to let the characters carry the narrative, rather than the other way around.

Those familiar with Cruise's recent work ("Cocktail," "Top Gun") might wince at abandoning the 26-year-old actor to his acting skills in such a dramatic role.

But Cruise shrugs it off.

"For myself it was a challenge. For myself, it was different. For myself, it was the best role that I've had in my career to date," Cruise said.

"I do feel that I have a better sense (of acting) every time I go on from a picture. You get more confidence - not cocky, like I know what I'm doing - but a confidence of trying scenes different ways and not getting locked into one idea of how to play a scene."

Hoffman, as is his custom, made story suggestions throughout filming. On several occasions, he checked with his autism experts to ensure the film did not "violate" the truth, as Hoffman put it.

When the script didn't withstand such challenges, it was revised. Any behavior by Raymond that might come across as "stupid," for instance, was excised. Autism, Hoffman was told, is a mental disorder, not retardation.

Whether or not such attention to detail will attract audiences remains to be seen.

"You have no idea what the audience is going to think," Hoffman said. "Underneath everything, there's a desire to have an impact on the audience. I don't want them to get up afterward.

"Arthur Miller said to me when we were doing `Death of a Salesman,' `You want to know when the play is really working? When the curtain comes down and you don't hear anything."'

-"Rain Man" features two of Hollywood's most noteworthy male stars. Here is a summary of their careers in the movies.

The films of Dustin Hoffman:

- "The Graduate," 1967

- "The Tiger Makes Out," 1967

- "Madigan's Million," 1967

- "John and Mary," 1969

- "Midnight Cowboy," 1969

- "Little Big Man," 1970

- "Straw Dogs," 1971

- "Who is Harry Kellerman and Why is He Saying Those Terrible Things About Me?" 1971

- "Alfredo, Alfredo," 1972

- "Papillon," 1973

- "Lenny," 1974

- "All the President's Men," 1976

- "Marathon Man," 1976

- "Straight Time," 1978

- "Kramer vs. Kramer" 1979

- "Agatha," 1979

- "Tootsie," 1982

- "Ishtar," 1987

The films of Tom Cruise:

- "Taps," 1981

- "The Outsiders," 1983

- "Risky Business," 1983

- "All the Right Moves," 1983

- "Legend," 1985

- "Top Gun," 1986

- "The Color of Money," 1986

- "Cocktail," 1988