When director Gil Kenan began visualizing City of Ember, he made drawings of key elements, like its signature grid of lights. Courtesy of BUF Compagnie. All images © Walden Media & Twentieth Century Fox.

If there's truth to the adage, "Show me your friends and I'll tell you who you are," then we're learning a lot about director Gil Kenan from some very good company he's been keeping. It was Kenan's animated UCLA thesis short The Lark that caught the attention of Steven Spielberg and Robert Zemeckis -- who tapped the 20-something filmmaker to direct the performance-captured Monster House. Kenan turned in such an accomplished film with his debut effort that it earned an Oscar nomination for Best Animated Feature. The Lark had also led Kenan directly to a meeting at Tom Hanks' production company Playtone, where he saw an advance manuscript of a young readers' book called City Of Ember. Four years later, City Of Ember has become Kenan's second directorial effort, with Tom Hanks producing.

Released today by Fox-Walden and starring Bill Murray, Tim Robbins and Martin Landau, City Of Ember chronicles the adventures of two teenagers (including Oscar nominee Saoirse Ronan from Atonement) as they attempt to escape a dying city. The teens must elude capture by the authorities and navigate a frightening labyrinth of tunnels and underground waterways to make their escape. To bring this tale to the screen, Kenan collaborated with scriptwriter Caroline Thompson, Production Designer Martin Laing, Special Effects Supervisor Kit West, Visual Effects Supervisor Eric Durst and a raft of visual effects companies that included BUF Compagnie, Luma Pictures, Amalgamated Pixels and Below the Radar. The visual effects work complemented the live action that DP Xavier Pérez Grobet filmed on a huge city set that was built within the world's largest ship hangar in Belfast, Northern Ireland.

Kenan explains, "The way that the aesthetic for this film was achieved was that I sat down with my art department and we started by designing a perfect utopia: a totally clean, modern master-designed city that was built for functionality and for flow -- all the things you would do if you set out to design a city from the ground up. Then we let time ravage it. We referenced lots of cities that have gone to pot all over the world for various reasons. We were able to see how time and atmosphere -- or a lack thereof -- have affected them. It was a fascinating experience."

Author Jeanne DuPrau originally envisioned City Of Ember as a subterranean city that had been illuminated for 200 years by a grid of lights. But the deeply buried generator that powered the grid was failing, and Ember's flickering lights and dwindling food supply were signaling the city's imminent demise. "I couldn't put this book down," recalls Kenan, who turns 32 this month. "Having grown up at the end of the Cold War, I was always deeply fascinated and disturbed by the idea of the end of the world. It's so deeply imbued with the idea of limited resources and the way we're using our time on this planet, and also our emotional attachment to the place we call home. All these things got me excited. I think that the notion of telling a story grounded in an alternate reality that's derived from our own -- but that is its own closed world -- really took me away. If I think back to who I am as a moviegoer rather than a moviemaker, the idea of going to see a movie about an underground world lured me in."

Luma created added a key component of the generator system in the form of giant waterwheels that churn Ember's underground river into electrical power.

A curious thing happened to Kenan as he began visualizing Ember. He made drawings of key elements, such as its signature grid of lights. But he also found himself unconsciously adding elements. "I pictured these big, droopy moths hanging around on the electric lines between the lights. They're kind of oversized -- like the size of golden retriever puppies! When I read the book the first time, for some reason I saw those things. When I went back to look for them in the book, they weren't there. But at that point it was too late -- I had already drawn them!" Animating those [3D] moths would become part of the assignment for the Paris-based CG studio BUF Compagnie.

Kenan also imagined that in the dark "pipeworks" tunnels snaking beneath Ember there would be a mole scurrying around in search of food. "Like everyone else in Ember who's hungry and will do whatever it takes to get by, this mole is hyper-aware and hyper-hungry. I felt that it was my duty to make the world as alive and varied as possible. So that's where these notions came from." Animating the mole in CG would be handled by Luma Pictures in Venice, California.

"Luma also did all the generator sequences," notes Kenan. "Another avenue that I exaggerated from the book is the notion of this generator -- it's a critical component in whether the city makes it or doesn't. It's like a beating heart. That's the metaphor I kept driving, so I wanted to create an extraordinary machine that was designed with all the mechanics of it concealed, so that it was never considered something that would need upkeep. For me, when something is important thematically it becomes important visually in my parsing of the story. So this generator became an icon of the film for me and was one of the first drawings that I made. That drawing basically ended up on screen. What we ended up with was this totemic, monolithic structure that's almost eight stories tall. Luma made it as a CG structure because we wouldn't have been able to build that."