<P> Roger Birnbaum was the first studio executive to give the film a green light; he did so immediately after Barry Morrow pitched the story . Birnbaum received "special thanks" in the film's credits . </P> <P> Agents at CAA sent the script to Hoffman and Bill Murray, envisioning Murray in the title role and Hoffman in the role eventually portrayed by Cruise . Martin Brest, Steven Spielberg, and Sydney Pollack were directors also involved in the film . Mickey Rourke was also offered a role but he turned it down . </P> <P> Principal photography included nine weeks of filming on location . Other portions were shot in the desert near Palm Springs, California . </P> <P> Almost all of the principal photography occurred during the 1988 Writers Guild of America strike; one key scene that was affected by the lack of writers was the film's final scene . Bass delivered his last rough cut of the script only hours before the strike started and spent no time on the set . </P>

Where did the name rain man come from