Weekend fun: The making of the Sony 3D 'Two Worlds' spot

Just over a year ago, Grey London pitched for a new client: Sony. A brand with a legacy that would fill any creative with both terror and excitement. The company wanted to show off the power of its range of 3D goodies. All it needed was something spectacular, something that could compete with the best from Hollywood. Not too much pressure, then.

We looked at all the 3D work that technology brands were pumping out. It was all high-octane stuff - cars flying out of your TV and spectacular explosions - but we'd seen it all before. Special effects just aren't that special any more, are they? Nothing pulled on the heartstrings. Could 3D make you feel something deeper than 2D? It was worth a punt, so we set about devising a classic love story told in 3D.

It was at this point that Nils Leonard, Grey's executive creative director, whipped out the beautiful Leonard Cohen poem That's What I Heard You Say and, after a couple of days of welding in the edit suite, a mood film popped out that combined it with the beautiful visuals of Arev Manoukian's short film Nuit Blanche.

The client fell in love with the idea, and it quickly carved and hacked its way though various levels of Sony management until it reached the president of Sony, Sir Howard Stringer. He said yes.

Now all we needed to do was convince Cohen (who is legendary for not getting involved with advertising) and Manoukian (who had also never made an ad before) to get involved. Over to Jacqueline Dobrin, Grey London's freshly appointed head of TV, to pull it all together. We wished her luck and off she went, nervously punching numbers into her BlackBerry.

Half-a-billion phone calls later, we're on a plane to Toronto. It's February, it's cold and Jacqueline looks slightly older than she did five months before.

We were confidently armed with 1,500 frames of meticulously planned previsualisation, but we still didn't have our two principal actors. We had cast our net very far and wide, but no joy. It wasn't until the day before the pre-production that we lucked upon our effortlessly beautiful female lead (oddly, she was an account exec from a Canadian agency) and the annoyingly handsome, but comically named, Robbie Tickle.

We then spent five days filming at 2,500 frames per second under a million watts of light. The director of photography informed us that if we had shot outside in full midday sun, it wouldn't have been enough to light the scenes. We built a book-throwing catapult, a cannon that fired bricks and rubble, and the art department went berserk with dry ice. As we were using only tiny snippets of the action, it was impossible to judge anything until we saw it back in super slo-mo. After 12 hours of watching, our eyes started to hurt.

It was then over to the mind-boggling 3D wizardry of the Los Angeles-based post house Digital Domain. Somewhere along the road, someone, possibly a lunatic, suggested that we build all the backgrounds from scratch. Apparently, we'd have more control over every aspect of the 3D and we could create whatever world we wanted.

In fact, very little in the ad was shot in camera. None of the buildings, roads, cars, interiors, skies or pigeons are real. Everything is sculpted in CGI and in 3D by some very clever people in small rooms who dream in 1s and 0s. This is quite difficult in 2D, but doubly hard in 3D - imagine doing everything twice, but from a slightly different angle.

Actors filmed. Landscapes built. Interiors designed. Now all we needed was a soundtrack. At the time, Black Swan had just won an Oscar and some bright spark piped up: "Phone that guy." So the ever-withering Miss Dobrin pootled off, punching an arthritic finger into her equally worn-out phone.

Enter stage right: Mr Clint Mansell, a talented Brummie with a penchant for haunting soundtracks (who, again, rarely agrees to get involved with commercials), hops on board. The triumvirate was complete: Cohen, Manoukian and Mansell. An impressive bunch, and three lovely fellows to boot.

We recorded the soundtrack at Air Studios in Hampstead. Watching 30 human beings perfectly in time and emotionally plugged into a piece of music, without ever having rehearsed it before, was an experience to behold. They nailed it in one take. The TV producers all wept and Mansell grinned and said: "Right, let's go to the pub, then." We did - for Scotch eggs and wine.

The final piece of the puzzle was Cohen. He'd agreed to re-record the words, so it was back to LA to meet the man who'd written the words that inspired the whole thing. It went swimmingly; we were happy, the director was happy, the client was happy. But Cohen wasn't. He called up the next day and said he loved the visuals but wanted his words to work better. So he rewrote some of them there and then. A big fat cherry, and who were we to disagree?

It's probably fair to say that making an ad in 3D has been a massive learning curve - a curve that has weaved its way into several unknown dimensions. But the final piece of work is something we're all excited about. It's an homage to many things: poetry, love stories, megabytes, computers, Manoukian's beautiful film and, of course, the new-fangled world of 3D.

Dave Monk and Matt Waller are creative directors at Grey London. This article was first published on campaignlive.co.uk