As an auteur whose midnight movie classics, “El Topo” and “The Holy Mountain” captivated enthusiastic audiences, cult-film director Alejandro Jodorowsky set his sights on his most ambitious project yet — a feature film adaptation of Frank Herbert’s futuristic best-seller, “Dune.” In 1975, Jodorowsky began work on this most ambitious project. Starring his own 12-year-old son Brontis alongside Orson Welles, Mick Jagger, David Carradine and Salvador Dali, featuring music by Pink Floyd and art by some of the most provocative talents of the era, including H.R. Giger (“Alien”)and Jean “Moebius” Giraud, Jodorowsky’s adaptation of the novel was poised to change cinema forever. After two years, however, the project fell apart. Through interviews with legends and luminaries including Giger, Gary Kurtz (producer, “Star Wars: Episodes IV and V”) and Nicholas Winding Refn (director, “Drive”), and an intimate and honest conversation with Jodorowsky, director Frank Pavich’s film finally unearths the full saga of “The Greatest Science Fiction Movie Never Made.” Jodorowsky granted Pavich unprecedented access to his production materials on the ill-fated project, including the extraordinary hard-bound book of meticulous story boards, which Jodorowsky used as a “calling card” to pitch his film to Hollywood studios. Jodorowsky also provided candid and comprehensive interviews about his ambitious screenplay, and his global search for a stellar cast and crew to bring his vision to the screen. Extras: Deleted scenes. Vitals: Director: Frank Pavich. 2014, CC, MPAA rating: PG-13, 90 min., Documentary, Box office gross: $.523 million, Sony.