VFX: 'In The Heart of The Sea'
Karen Moltenbrey
Issue: January 1, 2016

VFX: 'In The Heart of The Sea'

In the Heart of the Sea is a literal whale of a tale. The story is inspired by the 1851 classic novel  “Moby-Dick” by Herman Melville, which recounts the obsessive quest of a sea captain hell-bent on revenge after losing his leg in a previous struggle with a huge white whale. The movie, though, is based on the 2000 non-fiction book "In the Heart of the Sea: The Tragedy of the Whaleship Essex" by Nathaniel Philbrick, about the sinking of the “Essex” by a vengeful mammoth white whale that turns the tables so the hunters become the hunted, and proceeds to stalk the survivors during the ill-fated voyage. This is the true life-and-death struggle recounted by survivors that formed the basis for Melville’s book many decades ago.

The movie’s drama, naturally, takes place on the high seas. A good deal of Sea was filmed practically, offshore in the Canary Islands and at Warner Bros. Studios Leavesden in the UK. According to Double Negative’s David Hyde, effects supervisor for Sea, filmmakers sailed a tall ship similar to “Essex” to the Canary Islands, enabling the visual effects department to shoot oceanscape plates from the deck en route that they later augmented with CG for panoramic seagoing scenes. 

At Leavesden, meanwhile, an exterior bluescreen was constructed for the harbor shots at Nantucket’s port, along with an “Essex” deck atop a hydraulic gimbal system used to mimic the pitch of the stormy seas. An interior water tank was constructed from shipping containers to house the smaller whaling boat rigs, also on a hydraulic puppetry system. 

The hydraulic rig was used to shoot close-ups of the so-called Nantucket sleigh rides – when the smaller whaling boats launched during a hunt were subsequently dragged across the water by a harpooned whale. 

“A substantial amount of the water was caught on film, which was very good for us,” says Hyde, noting that in some cases the practical water was then augmented with CG, while in others it was all-digital. 

“When we had a whale breaching or a dolphin breaking the surface, we would have to simulate that,” says Hyde. “And sometimes, particularly when using the interior tank, we would have to replace the water around the whale boats, to make them look like they were traveling at 17 to 20 knots while being dragged by a harpooned whale.”  

There were four main areas when CG water was required: for large seascapes that were not caught on film, for depicting boat and whale/dolphin interaction, for underwater effects, and for augmentation, such as white water to make the sea look choppier and for expelling water through the blow hole of the whales – creatures that are also computer-generated.

Making Waves

Generating the various types of water was done using Side Effects Software’s Houdini as well as DNeg’s in-house water simulation solver, Dynamo. Both are so-called FLIP solvers, a hybrid between a particle-based and a volume-based fluid simulation. 

“We were fully aware from the start that the turnaround times for complex simulations would be a big hurdle. And final animation could not be approved until we could review how the animation and FX interacted with each other,” says Hyde. “Even with the talented FX crew we had, the fact of the matter is these simulations can take many hours. It’s a slow process.” 

Of the 30-so effects artists on the feature, nearly three-quarters of them worked on the water creation.

The effects leads – Robert Pearson, Chris Ung, and Menno Dijkstra – were constantly developing tools and techniques through production to streamline the sim process. “If you can save a couple of seconds per frame of simulation, on a 200-frame shot where you do the sim a number of times and then across a production with many shots, that time-savings can be substantial.”

The group used Sea to push the studio’s Dynamo in-house solver forward with new features. “We picked a number of shots we said we would push through the software, and it was quite successful. We would jump back to Houdini if we sensed we could get better results, and vice versa – there were certain features in Dynamo that were better for certain shots,” says Hyde. “This gave us more than one option and the freedom to try different things.”

Of course, having an in-house R&D team working on a piece of software has lots of advantages, and many of those involved changes that resulted in the important fast turnarounds. 

While Dynamo proved its mettle, Houdini was the main solver used. In fact, the decision was made early on to run the majority of the production’s pipeline through Houdini, with the reasoning that everything was so tightly coupled together – from postvis, to effects, to lighting. Rendering was done in Mantra for the most part, with the “Essex” destruction sequence rendered in Maya with Pixar’s RenderMan. “Keeping everything within one package was the ideal route because it meant everyone was working off the same platform, and it proved successful,” says Hyde. “We were able to develop a very streamlined pipeline by staying with Houdini.”

One of the main challenges recognized early in the process was how to integrate the live action, animation, and effects simulations. Hyde explains: “A whale breaching or interacting with the surface, for example, would need a representation of the CG water surface for animators to realistically animate to. Likewise, with the action footage of the hydraulics, the water surface has to behave so it looks like it initiated the movement of the boats.”

To this end, the group implemented a high-level postvisualization stage before proceeding to shot work. 

“Here we generated procedural water surfaces rather than dynamically simulating them, and Artist Geoffrey Coppin matched the look to the various sea conditions caught on film for animation timing,” Hyde says. “So when the whale comes up to breathe or the boat dips a certain way, we used these surfaces for pumping the waves into our dynamic water surface simulation.”

Once timing was worked out on the procedural surfaces at this postvisualization stage, the team ran a low-level simulation, using this procedural surface to pump in the wave velocities, to get the same type of waves flowing through the simulation dynamically. If all behaved accordingly and the broad movement was approved, the effects artists kicked off a high-resolution simulation. Depending on the size of the area, the simulation could take a few days to calculate and generate a couple of terabytes of data. 

“The turnaround times were quite lengthy when we got into the high-quality simulation settings,” says Hyde. 

Next, the effects artists used that dynamic patch of water the whale or boat would interact with, and they would add it back into the original procedural surface. As a result, the dynamic simulation would only be simulating the area of interest around the object. “It was very efficient,” says Hyde. “We were not doing large-scale simulations that we didn’t really need when the procedural water representation was just as good.”

Difficulties at Sea

According to Hyde, there were four sequences involving “heavy” CG water simulations, and they all had different requirements – from wide, expansive shots to others extremely close-up, and some underwater. “That is something we hadn’t faced before, having to accommodate such a variation of ‘water’ environments, but we were able to adapt and meet those shot requirements through tool and pipeline development. And it worked across most of the shots the majority of the time.” 

One sequence involves the initial whale hunt, when the “Essex” first comes across the large pod of whales. “The idea being the whaling crew had been at sea for months and didn’t see anything, then suddenly they come across all these whales,” he says. “We had to simulate many whales for this epic look.” 

Early on in production, the animators built multiple animation cycles for the whales so that the effects artists could build up a library of generic sims for placement in some scenes later on, such as this one.

Another challenging sequence involved the second whale hunt, when the leviathan first fully appears. “Big, wide shots with the whale charging out of the water at the ‘Essex,’ ” says Hyde. “Here the challenge was having convincing scale to the water in simulation areas approximately 300 feet wide in-camera.” 

The third is the other extreme, occurring at the end sequence when First Mate Own Chase (Chris Hemsworth), in one of the small whaling boats, confronts the great beast. The actors – and the water – appear in close-up. “We needed detail from one or two feet off the top of the water,” Hyde adds. Some of those sims were done over two or three days and generated 5tb to 10tb of simulation data each. 

The movie also contains a number of underwater effects that had to be approached differently than the surface water. Effects Lead Tamar Chatterjee created an approach that enabled the group to do a localized fluid simulation around the object that would be underwater, such as the whale or dolphin. That simulation mimicked the water currents that would flow around it in a real-world scenario. Next, the artists used the same approach for the channel bubbles, krill, and general detritus, to make them appear as though they were interacting realistically within a body of water. 

“We took the opportunity to re-create the style of the cinematographer and what he created on the production side, placing our CG cameras onto the whales and using very wide fish-eye lenses,” explains Hyde. “That, along with the effects, helped create a claustrophobic underwater feel and put the audience right there with the whales.”

Indeed, water scale is always an issue, and it was here. However, it is the attention to detail that sells the realism. “You are constantly trying to get a realistic look with the scale of the water. And to a certain extent, you can push the simulation within the constraints of memory and time. But then you have to augment it with white water, foam, spray, mist, and so forth. That is generally what sells it at the end of the day,” Hyde contends. “If you don’t see those details, it does not sell the scale. We were constantly battling to get the scale and detail into the water.”

For both the surface and underwater shots, secondary sims were generated for the atmospherics, like mist and spray. Primary sims were done on the whales to get the initial cresting and breaching, and then secondary sims were run to get the “sheet water” running off their backs as they crested. Simulations also helped achieve whitecaps, to make the ocean appear stormier. 

Almost all those sims were accomplished in Houdini. 

Overall, Hyde estimates the effects team generated more than a petabyte in water simulation data for the film. Fortunately, this amount of data did not sink the effects crew.

For the feature In the Heart of the Sea, some of the “Essex” crew overcame insurmountable odds and eventually conquered the elements, enabling them to eventually recount their harrowing journey. In Philbrick’s and Melville’s books, words are used to paint a vivid picture of this struggle. For the film, though, that task was given to the effects crew, which used state-of-the-art visual technology to bring this rich, visceral story to cinematic life.