Without wanting to ruin the mystery, here's how it works. Jesus VR was shot in the southern Italian city of Matera, which you might recognise from The Passion of the Christ, or Pasolini's The Gospel According to St Matthew, or the new Ben-Hur movie, or almost any biblical film with a location budget. On set cameras point in all directions, a little like an insect's compound eye, soaking up what's going on.Back in the editing suite, the footage is stitched together on computers. This creates a virtual bubble of moving images that you can "stand inside" by strapping on a virtual reality headset, which is basically a pair of jeweller's loops pointing at a high-resolution smartphone screen.When you turn or tilt your head motion sensors in the smartphone calculate the direction and angle of your gaze - over your shoulder, between your legs, it doesn't matter - and with silky seamlessness the screen shows you whatever was there, as if you were, too.If this is the future of cinema, make the most of big screens and communal experiences while you can. Even watched in Venice's dedicated virtual reality suite - 30 headsets and swishy white rotating chairs - VR films are a solitary experience.Nevertheless, it's a potential gravy train Hollywood is determined not to miss. Every major studio is currently pondering two key questions: what this new technology is capable of, and how they can make some money from it.But the technology isn't quite there yet. Despite the image's 4K resolution - in theory, as sharp as the best new HD televisions - the magnified pixels on the smartphone screen are visible, which renders colours grubby and actors' faces indistinct.In the Last Supper scene of Jesus VR , I struggled to pay attention to Jesus' words because I was so distracted by the disciples, who all seemed to be switching randomly between two facial expressions: beard-twirling solemnity and sea-bass-mouthed astonishment.During the crucifixion, I missed the nails going in because I spotted a jeering bystander who looked oddly like Jeremy Corbyn.The fact that the viewer's eyes and mind can wander isn't a flaw of virtual reality: it's the point.Halfway through the Venice screening of Jesus VR the film was paused so that its producer Alex Barder, the co-managing partner of production company VRWerx, could talk the festival audience through his game plan.For Barder - a bald Los Angeleno with black-rimmed glasses and a salesman's fastened grin - VR is cinema's next success story in waiting.He spoke excitedly about the 2.08billion smartphone users worldwide as Jesus VR's potential audience, even though it's only the (for now) significantly smaller number of VR headset owners who can actually watch it.The market is expected to balloon over the next two years, thanks in part to flat-pack models such as Google Cardboard, available for about R190,which could persuade sceptics to dip in a toe.Given the medium's potential, it's impossible to imagine that VR cinema won't catch on at some point.After seeing a VR film, it becomes clear that the two most basic building blocks of cinema - the shot and the cut - no longer work as they used to.Hard cuts are too disorienting so, until we acclimatise, scenes have to unfold in a single take. And the shots in Jesus VR are long, mostly static, and split up by gentle fades to black.The director's control starts and ends with his initial camera placement, which means the close-up is out, along with pans, tilts, zooms and shallow focus.Tracking shots still make sense, providing whatever it is that's moving the camera is either part of the shot or can be airbrushed out.And the audience's freedom to miss what matters means stories will have to be discovered rather than told, although without the interactive dimension of a video-game it's hard to imagine how this might work. ..