Jodorowsky's Dune Directed by Frank Pavich. Rated PG-13. Opens Friday.

Does it matter that the hypothetical film described in the documentary Jodorowsky’s Dune would probably have been a disaster? The account of cult filmmaker Alejandro Jodorowsky’s efforts to mount a movie version of Frank Herbert’s classic sci-fi novel Dune in the 1970s is an entertaining look at thwarted plans, centered around the fascinatingly weird filmmaker himself, who, now in his 80s, has lost none of his mad ambitions. His version of Dune was to have starred David Carradine, Mick Jagger, Salvador Dalí and Orson Welles, with music by Pink Floyd and designs by artists H.R. Giger and Moebius. Jodorowsky’s enthusiasm is infectious, and the movie makes a strong case that his ideas, though never realized, ended up permeating later sci-fi movies. Mostly it’s just a blast to hear him talk, and probably a lot more enjoyable than it would have been to watch the mess of a movie he’s describing.