'Babel': Evoking the Ancient Myth with CG

If you have the QuickTime plug-in, you can view a clip of CG Tokyo created by Intelligent Creatures for the movie Babel by simply clicking the image.

In one of the most ambitious movies of the fall season, master storyteller Alejandro Gonzalez Iñarritu (21 Grams) invites us to a thought-provoking journey in Babel (opening Oct. 27 through Paramount Vantage). When a rifle shot detonates in the Moroccan desert, it sparks a dramatic chain of events that ultimately ties the life of four disparate groups of people in different parts of the world. Filmed in four different languages, the movie evokes the ancient myth of Babel and its modern day implications. Gonzalez Iñarritu particularly wanted to tackle one of the growing contradictions of our world: at a time when its become possible to communicate with anyone at anytime, anywhere, more and more people feel isolated and lonely.

Since the action takes place on three different continents (Morocco, downtown Tokyo, Mexico), Gonzalez Iñarritu wanted to develop a distinctive film style for each of the four interlocked stories. Director of photography Rodrigo Prieto (Brokeback Mountain) decided to represent the characters individual emotional journeys through the use of different film stocks and formats. With this technique, each story acquired distinctive film grain, color saturation and backgrounds with varying degrees of sharpness. The intention was to make the audience feel like they were in different places, both geographically and emotionally. The various formats were then combined into one negative.

Coping with Film Grain

For lead vfx vendor Intelligent Creatures, this approach presented a unique challenge. They decided to go with three film formats, giving each storyline a unique texture to reflect the stories and locations, explains ceo and vfx supervisor Lon Molnar. 16mm was used for scenes in Morocco including scenes with Brad Pitt and Cate Blanchett. For the sequences in Mexico, they went Super 35, and for Tokyo, they opted for anamorphic lenses. Using several formats can be challenging, for specific reasons. Each format should be treated as almost a different project, and you need to take in consideration things such as aspect ratio, film stock and mainly grain. 16mm had larger grain, which meant that tracking was problematic, and any paintwork would have to be paid close attention to, making sure to match grain seamlessly.

At Intelligent Creatures, Molnars team included vfx producer Darren Bell, associate vfx supervisor Lev Kolobov, 3D supervisor Wayne Traudt, project manager Chris Nokes, and lead compositor Laurence Lok. Other key artists on the project were matte painters Dan Wheaton and Tim Warnock, with additional 3D support from Dominic Cheung. All the shots were composited in Fusion, with support from Maya.

For Iñarritu, it was of paramount importance for the visual effects to remain unnoticed. They were to be used solely to enhance the images that had been captured on location, and in one occasion, to create a shot that couldnt possibly be shot for real. Babel is a perfect example of a movie that needed sophisticated visual effects, but in which those effects should be seamless and totally invisible to audience, Molnar says. We did some various paintwork fixes, wire removals, a wallet pic replacement, a sequence involving removing the head of a chicken and blood enhancements to Cate Blanchetts character for a number of shots. It was mostly work hidden from a mainstream audience, yet challenging to work on nonetheless.

Creating a CG Tokyo

The team met a real challenge with the final shot of the movie. Taking place in Tokyo, it starts on a rooftop and ends up high above the city. The plate was originally captured on top of a 30-story building with a dolly and a crane. It went out 30 ft, but the director wanted the camera move to be extended by thousands of feet, as if the shot had been photographed from a helicopter. For Intelligent Creatures, it meant creating a photorealistic replica of Tokyo to simulate the camera panning back for an entire minute.

It was the last shot of the movie, a very dramatic moment, Molnar observes. Not only did the shot need to look 100% real and match previous shots of Tokyo at night, but it also had to support the last bit in the story, and bring emotions to the audience. So, real/seamless and emotional impact became our two main goals. Our major challenge was the deadline. The movie had to go to the Cannes International Film Festival, and we had eight weeks to finish this task with limited crew. Time was a real pressure factor, but looking back now, I think this actually helped us to achieve perfect results. In order to produce a real/seamless shot in limited time, we realized we had to identify the key elements that would make the night city look real. We decided to concentrate on those key elements, recreate them digitally and then add the rest of the elements to support them. In terms of the emotional impact, parallel to finding key elements, we also were trying to lock the camera move with Alejandro, and to insure the correct composition that would best support the story and his vision. We also started to look into some Tokyo landmarks that were important to the director.

Once the plate was shot in Tokyo, the team went through a period of concept design. Using Google Map, they found the exact location of the building, but eventually decided to move it to another location where it would support the story better. The top satellite view was then converted to a 3D model. Some buildings were repositioned to create a better composition, and the Tokyo landmarks were finally added in.

The original camera move was tracked, and a projection camera was set up to project the sequence frame by frame into Maya. We ended up projecting the entire plate onto 3D geometries. Yet, since we were so tight on the main characters, we had to roto them out in 2D, utilize the roto in 3D space to project them back onto a 3D card. We then took the new projection plate camera and combined it with a CG hookup cam which carried us through the remaining move, making the original crane/dolly move and the 3D helicopter move both seamless.

Focusing on Key Elements

To create the shot, the team used Photoshop mainly for matte painting, boujou to track the plate, Maya to model the city and to create the extended helicopter camera move, and then Fusion for final compositing. Once we had a full 3D model, we first got the camera move approved by the director, Molnar adds. The city was next split into blocks based on a topographic map, and each block was then split into rows. As we began to add layers and layers of matte paintings via camera projections, we rendered 4K ambient occlusion passes to preview the shot in order to make sure the models were working. An artist painted thousands of windows, one by one, for multiple glow and reflection passes. The distant background was multilayered by a 2D artist with minimal parallax, combining multiple live-action Tokyo skyline plates.

We tech scouted a few buildings in the area attempting to find the appropriate composition for an end point of the helicopter shot, or at best a point of reference. I took a few snapshots, brought them back to Alejandro and Rodrigo, selected the point, then went back to that location with a 16 megapixels digital camera equipped with 300mm zoom lens. I mapped the hero building, and took film reference from that vantage point. In our 3D representation of the city, the hero building had most of the details of the real thing, including the actors being projected back onto geometry, so we could create this camera move completely digitally. We also did tests to see which blocks we could get away with as low-resolution models and textures. The landmark buildings that were more recognizable were treated in high resolution, giving them further detail.

The multiple layers were rendered in mental ray. Since the shot was speed ramped over time, the 3D team wrote a quick script to only render the frames that were used in the final cut, thus saving a lot of render time. When we started to render the shot, we began with quick tests, looking at the minor things that make a city come to life, the fine details. One of them is the city street lights: as a camera moves, they reveal themselves and hide behind trees and other structures. We would look at these passes individually, soon realizing that these subtle details gave the city some major realism. We also created street bounce passes to get the lower ambience from a city nightlife, and focused our attention to the vast amount of reflections, which were a huge selling point creatively. We got a lot of life from vehicles too. Finally, helicopters were layered in, along with rooftop red light passes, which are seen everywhere in Tokyo. The whole live-action plate piece, with the full digital move, was rendered as a separate pass, then combined with our remaining digital city to complete the shot.

Digital Make-up

While Intelligent Creatures was rushing against time to complete its assignment, Lola Visual Effects was busy creating effects shots that had to be even more invisible to the audience. Specialized in cosmetic enhancements and touch-ups (including the groundbreaking rejuvenating effect in X-Men 3), the company was called on the project to perform various tricky tasks. Those included digitally retouching actors make-up in scenes that had been shot in 110° heat, but also involved cosmetic work that should remain confidential, as always with Lola vfxs projects. The assignment was supervised by Edson Williams, with vfx producer Thomas Nittman.

"While shooting his movie Gonzalez Iñarritu discovered that our type of communication had left some parts of this world still unaffected," Molnar concludes. "When he selected a remote Moroccan village to become a key location for the shoot, he was puzzled to find out that, in 2005, none of its inhabitants had ever heard of Brad Pitt!" A perfect setting for the movie, indeed.

Alain Bielik is the founder and editor of renowned effects magazine S.F.X, published in France since 1991. He also contributes to various French publications and occasionally to Cinefex. Last year, he organized a major special effects exhibition at the Musée International de la Miniature in Lyon, France.