In Ayn Rand's 1940s bestseller "The Fountainhead," architect Howard Roark blows up a housing complex he designed because the developer changed its style.

It was a dramatic act and a dramatic role for an architect. And when the book became a movie starring Gary Cooper, producers asked the dynamic real-life model for Roark--Frank Lloyd Wright--to design the movie sets.

While Wright never became the film's designer (his fee was too high), "The Fountainhead" movie made glamour boys of modern designers and confirmed Hollywood's long fascination with architecture.

In filmmaking today, "Blade Runner" designer Lawrence Paull said, architecture and architects continue to play major roles.

"In architecture and in movies, the crossover between fantasy and reality has a history as old as film itself," said designer Syd Mead, a "Blade Runner" collaborator.

"From the beginning, the distinction was blurred," said Mead, "especially in Southern California where many buildings have the fancifulness and flimsiness of sets."

Los Angeles' popular "programmatic" architecture, in which buildings mimic the shape of the things they sell is derived directly from the construction techniques of movie set design. The hot dog-shaped Tail O' The Pup fast-food stand in West Los Angeles is a good example.

In a more dramatic blurring of art and life, D. W. Griffith's splendidly decadent Babylon set from the movie "Intolerance" glorified the intersection of Sunset and Hollywood boulevards for years after the 1916 movie's debut.

In 1927, the architecturally prophetic movie "Metropolis" was released. Director Fritz Lang's gloomy Teutonic masterpiece modeled its menacing 150-story skyscraper on an unbuilt Ludwig Mies van der Rohe design for a glass tower in Berlin.

"Film and modern architecture grew up together," architect Craig Hodgetts recently told a USC symposium on architecture and film. "Both disciplines explored new ideas about the representation of space, and both disciplines shared--and still share--a profound ambiguity about the contemporary world."

Some critics argue that film set designers have been far more successful than modernist architects in winning acceptance of new ideas about how a changing world should or might look.

"Modern architecture itself may have left the public cold, but modern architecture in the movies caught its imagination by embodying . . . their fears, hopes and aspirations," wrote Donald Albrecht in his book "Designing Dreams."