Vivienne Chow Sam Neill, Christoph Waltz and Patrick Gibson will head the cast of “The Portable Door,” a fantasy adventure film adapted from the series of novels by Patrick Holt.The film is now shooting in Queensland, Australia, with Jeffrey Walker (“Ali’s Wedding,” Sky’s “Lambs of God”) directing from a script by Leon Ford (“Griff the Invisible”).The story sees two lowly, put-upon interns at a mysterious London firm, J.W.