On Holy Ground
By Karen Moltenbrey
Issue: Volume: 29 Issue: 7 (July 2006)

On Holy Ground

The Church of Saint-Sulpice, it is said, has the most eccentric history of any building in Paris. Built over the ruins of an ancient temple to the Egyptian goddess Isis, the church possesses an architectural footprint matching that of Notre Dame to within inches. The sanctuary has played host to the baptisms of the Marquis de Sade and Baudelaire, as well as the marriage of Victor Hugo. The attached seminary has a well-documented history of unorthodoxy and was once the clandestine meeting hall for numerous secret societies. Embedded in the gray granite floor, a thin polished strip of brass glistened in the stone…a golden line slanting across the church’s floor. The line bore graduated markings, like a ruler. It was a gnomon, Silas had been told, a pagan astronomical device like a sundial. Tourists, scientists, historians, and pagans from around the world came to Saint-Sulpice to gaze upon this famous line. Slowly, Silas let his eyes trace the path of the brass strip as it made its way across the floor from his right to left, slanting in front of him at an awkward angle, entirely at odds with the symmetry of the church…. The strip finally arrived at the base of a most unexpected structure. A colossal Egyptian obelisk. —From The DaVinci Code  

In author Dan Brown’s popular novel The Da Vinci Code, this ancient church was the setting for a scene in which the albino monk Silas believes he has located the hiding place of the mysterious keystone (Holy Grail); after all, the brothers, immediately before their deaths at Silas’s hands, all had given him this precise location for the object he desired: beneath the brass Rose Line that ran through Saint-Sulpice.
In this scene and throughout the book, Brown uses an actual place, object, or person on which to weave his tale, and adds an element of mystery or mystique, or builds on current lore, to infuse it with added drama. For example, historical records show that the actual Saint-Sulpice was in fact built upon another structure—an ancient Romanesque church constructed during the 13th century, rather than an ancient Egyptian temple, as the book states. And, indeed, there exists a strange, brass meridian line that runs through the church floor to a gnomon of white marble, both added in 1727 on orders by a Saint- Sulpice priest to help determine the equinoxes (and, hence, Easter). With such a thin line often separating real-life fact and Brown’s fiction, it’s no wonder the two blend together so well in The Da Vinci Code that it becomes difficult to separate one from the other. And for many, that is what makes the book so interesting—so much so that several industrious individuals have started so called Da Vinci Code tours, taking fans to many of the locales detailed in the book. But, it’s one thing to write about these actual locations and quite another to film there, as director Ron Howard soon discovered when he set out to make a movie that accurately depicted the events from the book. “In re-creating Dan Brown’s book, the director faced a lot of actual locations that are integral to the plot. And while many movie scripts start with something like, ‘opens on a beach in Hawaii,’ due to budget constraints, it will end up being ‘opens on a beach in Vancouver,’ or some other cheaper solution,” says Rainmaker VFX supervisor Mark Breakspear. “But with this story, to tell it accurately, you had to use the actual locations because they are intertwined with historical facts that appear in the book.”
Such was the case with Saint-Sulpice, a church whose unique architectural style sets it apart from ancient cathedrals, as Brown accurately describes in the book as Silas enters the building:
Unlike Notre Dame with its colorful frescoes, gilded altar-work, and warm wood, Saint-Sulpice was stark and cold, conveying an almost barren quality reminiscent of the ascetic cathedrals of Spain. The lack of décor made the interior look even more expansive, and as Silas glanced up into the soaring ribbed vault of the ceiling, he imagined he was standing beneath the hull of an enormous overturned ship. Kneeling in the first pew, Silas pretended to pray as he scanned the layout of the sanctuary. Saint- Sulpice, like most churches, had been built in the shape of a giant Roman cross. Its long central section—the nave—led directly to the main altar, where it was transversely intersected by a shorter section, known as the transept. The intersection of nave and transept occurred directly beneath the main cupola and was considered the heart of the church…her most sacred and mystical point.

Because filming was not permitted inside the actual Saint-Sulpice Church, designers constructed a
 partial set for a scene at Shepperton Studios in the UK. Due to space limitations at the studio, the
 set was built 15 percent smaller than the space in the actual church.
“The director couldn’t swap this church out for any other while filming the scene,” says Breakspear. “So many churches look similar, but this one in Paris is so specific, with its 80-foot domed, vaulted ceiling; it’s breathtaking. People who visited the church would know if a substitute location had been used in the movie.” But getting the Vatican’s approval to film inside the church was out of the question, as it had denounced the book and, therefore, the movie. This presented Howard and, eventually, his visual effects supervisor on the film, Angus Bickerton, with an enormous obstacle, one that was eventually overcome using computer graphics.
CG Building Blocks
Months before, Bickerton had worked with Breakspear and Rainmaker on the 2006 action/thriller Firewall, using projected textures to create a photorealistic digital backdrop of Seattle outside a high-rise office window—as it was filmed on location in Vancouver. As Breakspear explains, Rainmaker employed a technique whereby it used textures pulled from thousands of photographs and applied them to 3D objects and geometry. With NewTek’s LightWave, the team built accurate 3D models based on maps, and calculated correct lens angles using Google Earth, free 3D landscape software. “We used that information as a reference to determine how far some of the buildings should be, especially if you were using a 35mm lens and looking down from this giant window,” he explains.
As Breakspear points out, this technique is not new—it has been used in CG for years, mostly for a quick shot here or there, “I think with Firewall, we saw that this approach had way more possibilities than had been previously thought.” After the movie was completed, Bickerton moved on to another project: The Da Vinci Code.   But when the issue with Saint-Sulpice surfaced, Bickerton asked Breakspear if his solution from Firewall would work for this scene. Subsequently, Breakspear and Rainmaker examined hundreds of photos that Bickerton had taken at the church (photos are permitted, filming is not). They did a test, mapping the photos onto a simple digital model they had created of the church based on the photographic references.
“We did the test at full 2K resolution so we could see if it would hold up on film, as though you had a film camera and were walking down the church looking at the ceiling, which is the most amazing part. I did it when I walked in; [Bickerton] did it when he walked in. Everyone who goes to this church, the first thing they do is look up at the ceiling because it is so spectacular.” The group sent the test with the 3D camera moves to Bickerton, who liked it immediately. He, in turn, showed it to Ron Howard, who asked the visual effects supervisor how he got the shot considering the no- filming rule. “When [Bickerton] told him it was all-CG, that was it. Suddenly, we were in the running to get the sequence.”
For four months, Rainmaker worked to bid on the sequence for this highly anticipated movie, competing against a handful of other visual effects companies—namely Moving Picture Co., Double Negative, and The Senate, which were working on other segments that encompassed the lion’s share of the movie’s VFX shots. “We bid and re-bid, followed by some extra bidding and re-bidding, and eventually we got the job,” says Breakspear. “Once we did, all the niggling problems we tossed out during the bidding stage suddenly had to be solved. And one of those was that in the story, Silas arrives at the church at midnight, when the church is dark.”
Rainmaker’s plan was to take photos of the church during the day—the only time when it is open. But a church during the day is very different from a church at night, Breakspear points out. “Like any environment, it is completely different with the reflections, the way the light comes in,” he explains. “And here we had candlelight instead of daylight. It presents a whole new challenge.” This became yet another major hurdle for the artists.
Beginning their quest, Rainmaker dispatched several of its artists to Paris for a week to take photos inside the church. All told, the group acquired more than 10,000 digital pictures using a Canon 16- Megapixel camera. “It gave us insane quality,” says Breakspear. “We bracketed all our shots, and we had complete exposure ranges, like HDRIs basically.” Trying to blend in as tourists, which they technically were, the artists returned to the church every few hours to snap another round of pictures, even once taking photos of a bride and the wedding party. “I had a better camera than the wedding photographer, so it made sense to help them out!,” Breakspear says jokingly. “We had asked if we could take pictures at the church, though. We had a job to do, but we were trying to be respectful; it is a tourist location, but many people still go to there to pray.”
After returning from the photo session, the group examined the pictures. “We knew that we’d have no problem creating the effects for a daylight sequence,” Breakspear says. “But, how were we going to take these pictures and make them night? You really can’t do day to night using this technique; it doesn’t work that way.” Typically, effects artists accomplish this by a common technique of upping the blues, darkening the shot, and, if appropriate, comping a moon and some stars into the background, he says. But, that was never going to work on a movie of this scale; the quality would never suffice. “So, we had to develop a whole new process,” he adds.

Computer graphics, photographic textures, and a physical set comprise this scene inside Saint-Sulpice.
Top is the final shot that appeared in the movie. Middle is a photographic image taken inside the
actual church, whose textures were used for the final shot. Bottom shows the 3D wire frame imagery
used to augment the sparse set.
Lead compositor Mathew Krentz and lead CG artist Les Quinn came up with a plan whereby they would create the environment as if it were daytime but provide all kinds of alpha channels, maps, and controls to selectively grade and rebuild a nighttime version during compositing with Eyeon Software’s Digital Fusion. Then, they would composite greenscreened actors on top of the footage. “It looked fantastic, unbelievably believable,” says Breakspear.
Building the Church
The scene was filmed on a set at Shepperton Studios in the UK during a three-day period, one of which involved extensive previz and calibration of the film lenses to those of the CG cameras, and vice versa. A crew constructed the physical set—complete with 10-foot marble columns, wooden chairs, a replica floor made of shiny slabs of stone that looked as though they had been walked on for thousands of years, and more—that would then be augmented with CG set extensions. The dimensions of the set were acquired using a most unusual measure device: Bickerton’s foot.
“Angus [Bickerton] claims his feet are exactly 12 inches long. And because we couldn’t go in there to take precise measurements, he walked the space toe-to-heel as a tourist, to determine the length and width of the environment,” explains Breakspear. From those dimensions, the art department drew up a set plan, from which a 15 percent smaller version was built (to accommodate the size of the Shepperton stage).
In one corner of the set, the crew made a wall with frescoes and statues. It was here where Silas breaks the stone looking for the hidden treasure. Because of the way this part of the set was built, and the height of the columns, it was one scene where visual effects would not be required…in theory. “Because of the angle they chose, looking upward, we had to step in,” says Breakspear.
When filming began, the actors, director, producer, and DP were all looking at a big, 360-degree greenscreen. “It is the longest running visual effects shot in the movie—at 40 shots spanning about 3 to 4 minutes—and it was crucial that the actors understand their surroundings. Plus, there were no camera lockoffs; they had to move that camera around,” says Breakspear. “We brought up our digital model so they could see what they were supposed to be looking at on set. There are so many little things about the church where you just can’t say, ‘Look down the center aisle toward the entrance.’ From the center of the church back toward the entrance there is an enormous wooden organ, and depending on which lens you use and the angle, you are looking at only half of it or all of it in the shot; we needed to be sure of what we were looking at.”
In all, the crew shot nearly 60 different angles, 40 of which made the final cut. In turn, the CG team returned to Paris to make sure it had the proper photos to match. A few shots, however, such as those looking downward from the ceiling, were unattainable and the artists had to paint those using Adobe’s Photoshop. Later, the artists used Photoshop to import all the photos into CG, where they cleaned up the shadows, reflections, and so forth so they could be mapped onto the geometry and virtual models. Then, when they began refining the digital model of the church, they ran into problems.
“Our LightWave model is based on the pictures, and the pictures are based on the real church, which is the true size. The set, meanwhile, is 15 percent smaller, but not consistently so—16 percent smaller here, 14 percent smaller there,” says Breakspear. “Nothing was quite lining up with the photos. It was a funny moment where we would line up one end of the church and the other end would come unstuck. And we were already deep into postproduction when we discovered this.” In the end, Rainmaker did not use the expanded physical set, but rather a sparse version of it, with just the people, the chairs, and the floor. In one shot, everything but the actors was digitally replaced.

All the photographs inside the church were taken during the daylight. The digital artists turned the
scenes to night using a grading technique.
Good Night
The artists used 2d3’s Boujou to track the scenes and LightWave to map the photographic references onto the CG objects; next, they rendered them in various passes. As Breakspear stresses, all this was done with daylight textures. The group rendered out depth maps, matte passes for the columns, moonbeam elements coming in from the windows, smoke passes, a chandelier pass, and candle pass. “Candlelight was crucial because candlelight was present throughout the scene, flickering off people’s faces and the walls. It had to be extremely accurate, and CG candlelight doesn’t look real; it doesn’t react in the same way as the real thing,” he says.
To obtain footage of all the candlelight that would be needed for the scene, Breakspear gathered candles and, aided by a bottle of wine, positioned a DV camera looking at a candle, zooming into the flame full frame as he continued to blow on it to make it flicker. The artists then mapped that footage onto cards, and placed them in the shots. “Some of the shots with the candles, flames, and smoke had major camera moves, and we needed proper paral- lax added to the elements,” says Krentz. For that, the group used Fusion’s new 3D camera to import the Boujou track and apply the camera move to the elements.
But the real challenge came when the group adapted its photographic mapping technique into something more powerful—to turn day to night. According to Krentz, the group treated each individual shot as a matte painting. Neutralizing the sunlit renders was the first priority; next it determined which direction the moon would be coming from to create the beams filtering through the windows. “For most of the shots, we created the moonbeams in 2D, which were combined with the smoke elements for a hazy atmospheric look,” he says.
The most important part, Krentz notes, was keeping the actors’ skin tones warm from the flickering candles while also keeping the albino monk from looking “dead.” Rather than simply increasing the blues and decreasing the saturation, the artists actually converted the textures to reflect the evening light so the skin would retain its warm tone even in the darkly lit church. “When you go out at night and look at your skin, it doesn’t turn blue. You retain the same skin tone, a little darker maybe, but not blue,” says Breakspear. “It’s an obvious thing to say, but to fix it meant throwing away the old technique and having to do it differently.”
Digital artists took tens of thousands of photographs of the church from 60
different angles; 40 of those angles were incorporated into the movie by the
filmmakers for the Saint-Sulpice scenes.
Using what Breakspear calls a “pretty nifty” approach, the compositors used a grade on the film footage that made the textures look as if they were filmed at night, albeit in various “types” of night. This grading was accomplished inside Fusion, which ran on 3DBoxx workstations from Boxx Technologies. Working in floating point, the group used logarithmic film files from editorial, scanned them, and brought them into Fusion, a process done at Rainmaker’s London office. Although the studio had planned to open a location in London for some time, the decision was hastened by Sony Pictures’ encouragement to use UK facilities for the visual effects work due to tax credits, which turned into a substantial chunk of change given the number of effects in the film.
“A lot of us, myself included, are English or have English ties, so it was not problem,” says Breakspear. “And, Angus [Bickerton] had set up his office nearby, and could walk to any of the nearby VFX facilities working on the film, look at the shots, and make comments. It was inspiring to see the great work the other studios were doing.” Like Rainmaker, they were chosen for their roles based on previous work.
A New Arc
As Breakspear notes, the Saint-Sulpice scene was not the biggest overall visual effect in The Da Vinci Code, but it was certainly one of the most desired because of its length. Adding further appeal was the fact that it presented a great problem for CG and compositing. “It’s a real ‘visual effects’ visual effects sequence,” says Breakspear. “These are the types of shots we love to do. They are impossible to shoot, so the CG has to look real and blend in.”
In the end, a revolutionary process was born out of a perplexing issue. “It’s all about using new approaches to techniques we have taken for granted, and thinking about how far they can be pushed. We used a technique that companies know how to do, but we attempted it on something big, and along the way, had to solve problems that arose,” says Breakspear. Currently, Rainmaker is applying the lessons learned from this process to Dreamworks’ Blades of Glory, creating virtual environments and photoreal CG actors. “Had I attempted this before The Da Vinci Code, I would have panicked and hid under the desk!”
Not only has this novel process opened new doors for Rainmaker, but Breakspear also believes it will open the doors for producers to feel more confi- dent with CG and integrate it into production more frequently. “Accomplishing something like this strengthens the relationship between what producers think they can get away with and what they can really get away with,” he says. “It allows CG to be taken more seriously for the creation of larger environments.” In The Da Vinci Code, the technique was used to virtually construct an actual place, but it can also be used to re-construct places that no longer exist, such as long-gone historical sites, Breakspear points out. And, unlike the secrets in the movie, which have been hidden for centuries, Rainmaker has been extremely open about its work on the film, hoping to open the doors for others to push the technique, or CG in general, even further.
As he stood and examined his find, he realized he was holding a rough-hewn stone slab with engraved words. He felt for an instant like a modern-day Moses. As Silas read the words on the tablet, he felt surprise. He had expected the keystone to be a map, or a complex series of directions, perhaps even encoded. The keystone, however, bore the simplest of inscriptions. Job 38:11.  Finding verse number eleven, Silas read the text. It was only seven words. Confused, he read it again, sensing something had gone terribly wrong. The verse simply read: Hitherto shalt thou come, but no further.
Unlike the fictional character Silas, Rainmaker cracked the code that enabled it to complete the mission at Saint-Sulpice.

Karen Moltenbrey is the chief editor for Computer Graphics World.