Oscar-winning Star Wars visual-effects designer Grant McCune, who  created scenes with models and miniature films for more than three  decades, has died of pancreatic cancer, his production company said on  Wednesday. He was 67.    McCune, who died Monday at his home in Hidden Hills, 30 miles  northwest of Los Angeles, won his Oscar for 1977's Star Wars, the  original installment in George Lucas' six-film sci-fi franchise.    He shared the honor with John Stears, John Dykstra, Richard Edlund and Robert Blalack.    McCune also was nominated for an Oscar in 1980 for Star Trek: The Motion Picture.    Armed with a bachelor's degree in biology, McCune got his start on  Jaws, when he and Bill Shourt were hired to make a giant white shark  model; neither was credited on the film.    He later became a partner at Apogee Prods, where he worked on three  dozen films, including Die Hard, Never Say Never Again, Big, Space Balls  and Caddyshack. Striking out on his own, McCune such films...