Its documentary “Empire of Dreams” focuses on how the three movies were made — particularly the original. Now known as “Episode IV: A New Hope,” it was just plain ol’ “Star Wars” when it came out. And people like George Lucas and Harrison Ford were relatively unknown, even though they had worked together on “American Graffiti.”

But, in a way, it’s the success in “American Graffiti” that helped both of them negotiate that tricky path to success. Lucas knew the story he wanted to tell, but science fiction movies at the time were hardly big box office draws. And Lucas’ pitch was pretty sketchy.

Still, it was enough to entice Alan Ladd Jr., the studio chief of 20th Century Fox at the time — mainly because Ladd thought “American Graffiti” was so good.

“The technology part of the whole thing was completely over my head,” Ladd says on the documentary, referring to the “Star Wars” concept. “I just believed in him.”

The documentary also explains that Lucas wanted unknown actors to be his three leads, so Ford was ruled out because of his “Graffiti” role. But Lucas kept Ford around to help actors read their lines. Ford eventually did so well that Lucas relented and made him Han Solo — and a huge star.

And Ford believed in the director’s talent, even though the plot seemed shaky to the actors as the filmmaking began.

“Some princess with hair in weird buns on the side,” Ford recalls in the documentary. “A guy in a monkey suit or something. I mean it was weird — it was very, very weird.”