Assassin's Creed III: The Redesigned Anvil Engine

Designing yearly installments to a popular franchise is a daunting task.

Designing yearly installments to a popular franchise is a daunting task. Veer too far away from the formula that made the game successful and you can alienate the fan base. Stick too closely to the exact same formula and franchise fatigue can set in, with a gradual loss of consumers eventually burying you like Guitar Hero and Tony Hawk.

For the third numbered entry in the popular Assassins Creed series, Ubisoft Montreal knew it needed to shake up the foundation. Fans have eagerly devoured every entry in the building climbing, backstabbing, generation jumping franchise, but the team wanted to do more than just take the latest entry into a new historical time period. To achieve the separation the team wanted to have between previous Assassin’s games and this one, they needed drastically rework the technology.

Since an Assassin’s Creed game comes out every year, many people believe Ubisoft churns these games out in eight months just like a Madden or UFC game. In fact, this project began directly after the completion of Assassin’s Creed II. Immediately after shipping Ezio’s first adventure, the studio gave its core engineering team the task of redesigning the Anvil engine from the ground up in preparation for this game. While other teams at Ubisoft Montreal built Assassin’s Creed Brotherhood and Revelations, this sequestered engineering team spent its days imagining where it could take the technology and then making it a reality.

“When you’re working with engineers who have solved massive problems in the past and set the bar really high in terms of animation and character navigation, we knew we could push the bar,” says Assassin’s Creed III creative director Alex Hutchinson.

Dubbed AnvilNext, the new engine features several new technological toys for the game designers to work with, including deferred lighting, ambient occlusion, a new camera mode, and improved crowd AI that interacts more frequently with the player. Its most impressive leaps forward, however, are coming in the animation department.

Scaling Up The Fight Since colonial Boston and New York don’t have many signature buildings or visually remarkable locations to explore, Ubisoft Montreal wanted to capture the history of the period by placing players directly in some of the major events of the American Revolution like the battle at Bunker Hill. To do so, team needed to exponentially grow the number of characters that can be on the screen at one time. The engineering team went above and beyond the call. “We now have a couple thousand guys on screen, whereas before it was capped at around 100,” Hutchinson says. While you can’t direct troop movement like a Total War game or wield your hidden blade and start slicing throats across a Redcoat firing line – if you try, one of the thousand musketeers will put you in an early grave – the staggering number of troops certainly heightens your awareness and gives Assassin’s Creed III a sense of scale unlike any of the other entries in the series.

The Reanimators

When Hutchinson mentioned pushing the bar, just how high did he have in mind?

“Our goal with the new game is to have no animations from the previous ACs,” he says. “We don’t want you to see anything from previous ACs in this game unless we deliberately put it in there.”

Thanks to the rapid animation prototyping made possible by the new engine tools, the animators quickly got the first sets of animations into the game. Once the new character came to life on the screen, it was easy to see just how vast a difference the new look made. That was all the motivation the team needed.

One of the primary motivating factors in creating this new set of animations for the protagonist Connor was to give him a completely different feel from his predecessors Ezio and Altair. Even in the early demos, Connor walks, fights, and climbs differently than the previous Assassin leads. In fights, he is much more low to the ground, like a predator, and attacks frequently while duel wielding weapons. To make climbing on varied terrain like trees and cliffs look right, the team studied and emulated the techniques of real-life climbers.

Taking queues from animation pioneers like Naughty Dog (Uncharted), Ubisoft Montreal is also integrating situational animations to make the characters seem more real. Connor and non-player characters will flinch at nearby explosions, and if Connor approaches a hedge in a city on a tailing mission he’ll crouch automatically to avoid blowing his cover.

Another area of heavy work the team needed to tackle was navigating through the Frontier’s open expanse. Given the series’ reputation for impressive vertical navigation up the sides of buildings and historical landmarks, the team knew it couldn’t confine its newest assassin to the canopy floor and dirt roads. When Hutchinson told the engineers they wanted to allow players to not only scale cliffs, but to climb any tree in the forest, shimmy around tree trunks, and monkey bar across branches, several jaws hit the floor.

“I think that terrified a lot of people at the start of the project,” Hutchinson admits.

The engineers also need to confront one of the most daunting tasks in all of animation –fighting on uneven surfaces like sloped hills.

“Think about every game – just mentally picture it again – and you realize every [developer] has been very clever over the years,” Hutchinson says. “You run over these uneven terrains and then you get to the fight arena and, ‘Oh look, it’s flat.’ There are problems with foot placement, swordfighting with someone when they are above you or below you, the ragdoll when you collapse on the ground and you’re hurt – once you get away from flat ground it’s nightmarish to solve all of the problems.”

From what we saw in the demo, Ubisoft has quite the team of problem solvers. If you watch Connor’s feet as he moves bounds through snow, jumps between tree branches, or climbs the side of a cliff, his feet always appear grounded to the world. Don’t expect any of the strange gliding across sloped hillsides so prevalent in other open world games like Skyrim. To Ubisoft Montreal, these types of glitches break the fantasy and were a non-starter.

“Animation fidelity is such a big part of the Assassins brand that if we were going to do it we wanted to do it right,” Hutchinson says.

Read on to find out how Ubisoft Montreal is taking performance capture to the next level.