We’ve only just settled into leather La-Z-Boys at the back of Sledgehammer Games’ in-studio theatre in Foster City, California, but Chris Stone is already swinging for the fences.

“We set a goal early that we wanted the best looking characters not just in Call of Duty, but in games,” says the Advanced Warfare animation director.

To achieve such a lofty objective, Sledgehammer is using a new engine built almost entirely from scratch. It includes new rendering, animation, physics, and audio systems, and has dramatically changed the way Sledgehammer develops games.

Read the first part of this feature here:
How Sledgehammer is reshaping Call of Duty — Part 1: Story

The most obvious change was in the performance capture department. “Traditional performance capture is flawed,” contends Stone. “You have guys on a stage and cameras 100 feet away from them trying to pick up the location of a tiny mark.” On top of that, the old approach of using dots on actor’s faces tends to give a slightly unnatural, wooden look due to the limited data being gathered, he adds.

How Sledgehammer is reshaping Call of Duty – Part 2: Technical

As such, Sledgehammer worked with the team at Giant Studios that helped bring Gollum to life for Weta in order to do get similarly impressive results with its digital soldiers. That meant no dots, and getting up close and personal with the actors. “We put this high-definition camera two inches from this person’s face, we’re not missing anything,” Stone explains. “Every little bit of motion, the intricacies of every expression – we get it all.

“So when you see Jonathan doing a smile or a sneer, it’s not just us trying to interpret that expression, that is his expression, the exact expression he would make for that delivery.” This footage was augmented with scans of the muscles in each actor’s face, and likenesses were built from there. Each actor was filmed forming different expressions for the cameras and initially, 75 scans of each face was used. Once Sledgehammer realised what it could do with the scans, it found it needed more and more and more.

“Some of [the actors] really struggled with that,” says Stone. “The interesting thing I found with Spacey is that the man’s face is so expressive, it was like ‘Wow this guy can do anything’. We ended up getting one hundred more scans for him than any other character in the game.” That’s a lot of work, but the studio is obviously pleased with the results. “Even the wrinkles that are generated with those expressions are something that’s going to come across,” Stone says. “You can’t match it with any other tech.”

The word ‘photorealistic’ is even mentioned a few times in our studio tour, and that’s a standard that’s not too distant from what Sledgehammer believes it has achieved. “There are shots in our game that if you printed it out, I would challenge you to be able to separate which is a photograph and which is not – it’s pretty spot-on,” says Sledgehammer co-founder and head of development Michael Condrey.

Is the uncanny valley a worry then? “It’s always a risk,” says Stone. “We were concerned initially. I think we’ve done a good job of avoiding that. People aren’t looking at the game like it’s television – it’s just not there. But it’s at a place where it’s past that uncanny valley for sure.”

"As we started shooting, it became obvious that Spacey can bring a little more than what we pictured to a performance. The second or third shoot he really dialled it in."
Chris Stone, Sledgehammer Games
L.A. Codfidential

Sledgehammer’s new performance capture approach even had an impact on the way the game was cast. Rather than just searching for the right face and voice, more consideration was given to actors that could nail full-body performance, and also to those who had good chemistry with others. “We had people come in who we thought were great for Jonathan or Cormack, but because they didn’t act off each other as well, they didn’t have this connection, we didn‘t cast them,” says Stone. “What those [who were cast] brought to their performances – every one of them amazing. Obviously Spacey is the most seasoned of all of them, so he brings a lot more to that table.”

Despite having worked with Marlon Brando for The Godfather game (whose sickly performance was eventually replaced), Stone was anxious about ordering Spacey around. “The last thing I wanna do is walk onto a p-cap stage with an Academy Award-winning actor and tell him exactly what to do,” he says with a laugh. “He’s going to bring a lot more to this performance than I can probably give him.” During the first few shoots, Spacey and the team bounced ideas off one another, but sure enough, the actor soon made the role his own.

“We went into the performance capture sessions for Irons [Spacey’s character] with a really good idea of what we wanted this character to be,” says Stone. “As we started shooting, it became obvious that Spacey can bring a little more than what we pictured to a performance. The second or third shoot he really dialled it in.” There was even a House of Cards executive producer sitting on on the shoot for some scenes, and the distinctions between Irons and Frank Underwood (Spacey’s House of Cards character) were discussed.

It wasn’t all nuance, though. The guy who did the rigging for Man of Steel and Iron Man set up all the wire work for action capture shoots Stone calls as “a lot of fun and definitely a new avenue for games”. That rigging allowed the studio to properly emulate the effects of the game’s Exo-Suits, and allowed actors to “kick dudes 40 feet or whatever”, says Stone with a grin. One session only came to an end when director James Cameron finally kicked Sledgehammer off the sound stage so he could film Avatar 2.

How Sledgehammer is reshaping Call of Duty – Part 2: Technical
Gut punch

Film has had a large impact on Advanced Warfare’s sound design. “We wanted a clean, focussed mix like you see in a movie,” says audio director Don Veca. He refers to the way that the camera’s focus in film is always higher in the mix, with other noises in a scene somewhat muted. “Of course, in a movie you know what’s going to happen and can adjust the mix,” Veca adds. It took the creation of a new audio engine to get that happening in real time for Advanced Warfare.

Despite the huge Call of Duty audio library Veca and his team had to draw on for Advanced Warfare, every single one of the game’s sounds was built from scratch, often using field recordings taken by Sledgehammer. “These guys get to do some of the coolest shit you’ll ever see,” enthuses Condrey. “I’ve seen these guys standing on the end of a runway capturing jets flying 30 feet over their heads. I’ve seen them hang out the sides of helicopters getting the sounds of wind on the sides of a Huey. I had the chance to join them on one shoot where they were firing off mortars, and they were so close to the mortars that the microphones caught on fire.”

Lead sound designer Dave Swinson chased a garbage truck down the street in his pyjamas to record the whine of its mechanical arms.

The sound design itself took place in specialised ‘floating’ rooms decoupled from the rest of the studio’s building – isolated to prevent sound transfer muddying things up. In these small octagon-shaped rooms, the sound team was able to concoct audio that outputs with a greater dynamic range than prior Call of Duty games thanks to the greater storage space available on new-gen consoles.

Veca’s mantra when it came to the futuristic game’s audio was “believeable, advanced-sounding, but grounded” – the idea was to keep pew-pew-style lasers out. “We wanted advanced-sounding things that didn’t sound sci-fi,” he says. “Things that you hear every day that don’t take you out to that George Jetson world – it’s not Star Wars.”

For the game’s distinctive Warbird ship, that meant mixing recordings of jets and helicopters together, then adding layers of synthetic sounds. For its huge robot Walkers, lead sound designer Dave Swinson chased a garbage truck down the street in his pyjamas to record the whine of its mechanical arms. The sound made when the Exo Shield deploys is actually 20 tracks layered one on top of the other, one of which is a door being slammed.

Weapon audio was built in a similar fashion. “One of the main things we wanted to improve in this game was weapons, and I think we’ve come a really long way,” says Veca. One area of focus was on the difference between the noise of a gun being fired by someone else, and the noise of firing one yourself. “When I actually held [a gun], shot it, and felt it in my body, that was a different experience than hearing someone else do it,” Veca says. The sound reverberated through him, and he felt the way he had hearing a double-kick metal drummer for the first time. It was a mini-epiphany of sorts: “These guns need to hit you in the gut.”

We have the technology

When it first set up shop in Foster City, Sledgehammer Games was sharing a floor of its nondescript East Hillsdale Boulevard office with another business. When the developer was shoulder-tapped for what would become Advanced Warfare, expansion was on the cards, and as the story goes, the staff took to the internal wall dividing the neighbouring businesses with sledgehammers, eventually emerging from clouds of plaster having successfully doubled the studio's space.

It's an amusing legend, and one that's fitting not only because of the studio's name, but also because it can be seen as a metaphor for the development of Advanced Warfare itself: hard graft, mess, and the breaking down of systems to create something bigger and better. There’s certainly no doubt the Call of Duty franchise was in need of a serious overhaul. Precise figures are hard to come by, but the consensus online is that last year’s Ghosts was the lowest-selling Call of Duty title since 2008’s World at War.

Of course, no-one was more aware of this than Sledgehammer itself, so instead of an update, the game got a complete rebuild: a new engine, new animation, and new audio. Technical advancements do not themselves a great game make, but in this case they are powering brand new gameplay mechanics made possible by the addition of the Exo-Suit – a feature which singlehandedly “redefines how you’re going to play COD” according to Condrey.

Every Call of Duty title lands with a mountain of hype, and this year's title will be no different. But for the first time in a long time, it feels like serious risks have been taken with most facets of the franchise. So don't blink, because after three years of toil, Sledgehammer Games is finally at the plate. And when you swing for the fences, every now and then you hit one out of the park.

Call of Duty: Advanced Warfare is coming to Xbox 360, Xbox One, PlayStation 3, PlayStation 4, and Windows PC on November 4.

How Sledgehammer is reshaping Call of Duty — Part 1: Story