The unseen hands guiding ‘Zathura’

IN Jon Favreau’s “Zathura: A Space Adventure,” two boys left alone in their father’s house with their teenage sister discover a mysterious game -- and, in playing it, launch adventures that take them, and the house, into space. This being sci-fi, special effects are central to the movie (which opens Friday), and the effects crew used green-screen digital work and muscle to create them. A two-story re-creation of the suburban home was built on a massive hydraulic platform that could be rocked to simulate a liftoff or a blast from an alien rocket. Giant green-screen curtains circled portions of the suspended house on one side, and on the other, a hand-painted screen pierced with thousands of holes simulated a star-filled sky as seen from space.

For a scene in which an astronaut (played by Dax Shepard) flies through the roof of the space-bound house with a jet pack, there was no crane or hydraulic lift to power his flight. Instead, a crew of four men led by wire specialist Robert Harman provided the fuel. Using counterweighted pulleys, precise timing and muscle, they pulled Shepard smoothly up, re-creating the astronaut’s liftoff with precision.

Times staff photographer Damon Winter observed the filming, with an eye to capturing the work of craftspeople like Harman’s crew, who pride themselves on remaining invisible to allow viewers to suspend their disbelief and enter the world of the film.