Brothers in Arms
Karen Moltenbrey
February 4, 2011

Brothers in Arms

Assassin’s Creed: Brotherhood continues to intrigue audiences with its cutting-edge graphics and gameplay
Ubisoft Montreal made history with its title Assassin’s Creed, an historical-based video game that established a new genre of action-adventure game. Set in the present day, the story line centers around a bartender, Desmond Miles, who is forced to relive his ancestors’ memories so he can recover lost artifacts for a company that is a front for the Knights Templar. Miles’ ancestors, however, are assassins, who targeted well-known figures from history. In the initial release, players travel back in time, assuming the identity of the assassin Altair during the Crusades. In Assassin’s Creed II, they become Ezio in Renaissance Italy. In the latest title in the series, Assassin’s Creed: Brotherhood, players again assume the identity of Ezio in Italy during the Middle Ages, only this time his mission takes him from II’s Venice to Rome, where the latest action unfolds.

Here, CGW chief editor Karen Moltenbrey speaks with various members of the Ubisoft development team who brought the latest action to life. (For more on the creation of this game, see “Rome Reborn” in the January/February 2011 issue of CGW.)

How does this game differ from the other two Assassin’s Creed titles?
Producer Vincent Pontbriand: It’s Rome and so much more! Rome is three time the size of [Assassin’s Creed II’s] Venice and comprises four huge, distinct districts—which greatly affects how you play in them. The wealth distribution also heavily impacts the landscape of Rome—for example, Vatican City is full of tall buildings and well known landmarks. Meanwhile, the Roman Ruins is a location full of run-down buildings and old Roman ruins. [This sets the stage for the game’s] free-running, which requires precision jumps between the ruins, such as columns. There’s also the countryside which, due to the Seven Hills of Rome, has nice elevation and is a perfect playground for horse chase and a horse free-running sequence. Across Rome flows the Tiber, where boats slowly sail, adding interesting water gameplay.

Many of the characters that players enjoyed in Assassin’s Creed II (AC2) are back in Brotherhood. First off, Ezio Auditore, our praised master assassin who players saw evolve in AC2, will face his most formidable threat to date. Ezio will rise to the occasion by building a Brotherhood directly in the heart of the Templar’s stronghold, Rome. This seasoned assassin is now a legend, feared and fearless, introspective, wise, and mature, leader to his assassin’s Brotherhood. If AC2 was a revenge tale, Brotherhood is about rising up and becoming a leader.

New to Brotherhood is the ‘strike-first, strike-fast’ combat philosophy. Ezio is a master assassin and, as such, is much more skilled in the art of war than most of his foes. This means he can swiftly defeat multiples of unskilled enemies in a matter of seconds—he is on the offensive. With this new offensive-oriented attitude, Ezio can quickly strike first and use new moves, such as kicks, combo strings, and linked melee/ranged attacks, to do so. However, the AI is much more aggressive than it had been, since multiple enemies can attack Ezio simultaneously; thus, players will have to use Ezio’s best assassin skills to promptly parry and counter each strike. If players do not take the upper hand in fights, Ezio will be overwhelmed. All these elements make each fight even more visceral and visually impressive—and that much more fun to play.

Also, we introduce the ‘boss fights’ by adding one-on-one fight rules, to change from the past experiences. We added the kick move, too, which is used to create an opening; it is very useful against guards who always deflect your attacks. We also added support for heavy weapons; we added the ability to throw them to instantly kill any enemy (except the bosses of course). The list of new features is long! All these elements enable each fight to have more depth, as it requires more strategy; yet, it is as fun to play as ever. The kill animation are very visceral and impressive. I believe players will love it. Also, weapons can be used in combination with other weapons. For example, I love the new ability to use the gun to kill an enemy at a [distant] range after I just impaled another with my sword. Another big evolution is the use of the horse, and the development around it: the new moves that you can do to and from the horse—hijacking/being hijacked, assassination from the ground, from the horse, from the air, to the horse…. You can also have a free-running sequence using the horse. So, for example, you can jump from the horse, and then swing on a beam and jump on columns. Free-running sequences can also end on you horses—perfect to escape from a tight situation. It enables players to quickly travel through Rome, which is definitely very useful but also provides some of the best moments. For example, reaching the Colosseum, at night, on your horse, for the first time is a very powerful moment.

Describe the character modeling process and the challenges associated with that.
Senior character artist Laurent Sauvage: The first step in our process was to roughly create a base mesh, to lay down proportions, to capture the overall look of the model. Then, its details were sculpted using Pixologic’s ZBrush, shaping the primary form and adding more details to get to the secondary form, like folds, stitches, borders, and so forth. The tertiary forms (skin pore, fabrics fibers) were added later using Ryan Clark’s CrazyBump and Adobe’s Photoshop. Then, the model was re-topologized and unwrapped using Autodesk’s 3ds Max and other tools (depending on the artist). The high-resolution meshes were later projected on the final low-polygon model, creating sets of normal maps and occlusion maps.

The next step took place within Photoshop and Maxon’s BodyPaint, where the model was textured using photo manipulations and hand-painting techniques for the diffuse maps, and CrazyBump to create final highlights and micro details. Then the model was rigged to the skeleton using in-house tools, and sent to the animation department, where it came to life, thanks to mocap and keyframed animation.

What was the character animation process like?
Lead animator Mike Menillo: First, we (programmers, designers, and animators) have to conceptualize what new moves need to be done based on feedback from the public and things that we want to change in order to make the game better. Then comes prototyping, where the animator does quick animations so the programmer can implement them into the game; this lets us test it to see if it works—whether the timing is correct and if it’s fun. Once the prototype animations are done and everyone is happy with how it plays, we move onto the conception for the motion-capture session.

We would brainstorm ideas on paper or act out the scene in terms of what we thought would be a cool move; then once were happy with it, we would film it so we wouldn’t forget it. Then comes the motion capture. For the fight team, we had four mocap sessions. For the first three sessions, members of the team were in the suits, and for the last one, professional actors were hired to change it up a bit. We would show the rehearsed clips to the actors, do a couple of test runs to make sure everything would be captured correctly or where exactly to place the foam mats on the floor so the actors would not get hurt then, and then we captured the motion. Once we received the data from the motion-capture studio, we would clean the scene in 3ds Max. This is where we finalize the animations to get them ready to be put in-game by making sure the timing was correct, placing all technical markers we use to keep track of placement in the world and add anything to the animation that we think would make it better, like exaggerating moves or making the characters jump higher.

The final process is testing, testing, testing…. What I mean by that is we export the finalized animations into the game and make sure they work properly without any popping or visible bugs or glitches. Once that is all done, we move onto the next animation.

How much motion capture was used?
Menillo: We did four full days’ worth of motion capture: 80 shots, 200 takes, and about 250 new final animations for the fight. We used 3ds Max 2008 to clean and finalize the scenes. And everything was done in the Ubisoft motion-capture studio and cleaned by the animation team at Ubisoft Montreal.

Which character was the most difficult to create and animate?
Menillo: The only character I animated was Ezio, and it was challenging because we had to take into account many factors, such as his age, his skill level, and how we wanted him to fight that made sense in the time period the game took place in.

The game’s environments are stunning. How were they built?
Environment modeler Bruce Low: We created really detailed statistics based on what we did on AC2. We knew how many models of houses, landmarks, free-run elements we could create. Then, we asked all the teams (mission, cinematic, and so forth) what they needed from our artist. From that list, we created new architectural elements needed for the game. We then created a pipeline to make sure all our objects would work correctly in our game on every level. It had to work for everyone, from technical (the behavior of the crowd as it reacts with Ezio’s actions, such as climbing and running) to design (object placement in the world, elements used in free-running, and such), as well as graphics (polygons, textures, levels of detail, transitions, and what not). I’m really proud of the team and what we achieved. I believe that you only need to take a look from the highest point in Rome to understand how big this beautiful city is.

What was the most challenging environment to create?
Low: I guess the most challenging environment to create was Rome itself, especially to fit everything we needed from this gigantic city within our memory and frame-rate budget. We had lots of challenges, but rendering this massive amount of polygons was one of the most challenging processes on the technical side. We had to employ new technology, code optimization, to achieve a city this big. But since the team was the same, we knew how to work together, and we knew what could be done in such a limited timeline. We had to be specific and optimal about how many objects we would create. We had to have a strict pipeline for environment creation.

What were some other big technical challenges?
Lead AI programmer Stephane Assadourian: Producing such a huge a game with such a new scope, in only 10 months, was pretty challenging! First, I would start with the horse. In 10 months, we did not have time to rewrite the horse from the ground up, so we used the framework from AC1, which was not built to support features like horse-to-horse assassination, or air-to-horse hijack. There were also all our new technologies, like the Rome Upgrade System or the Assassins’ Guild. And with all the new moves we added and all the tools we gave the player, it was difficult to come up with our new fight system as it is today.

Were there any new techniques or technologies created for this game?

Assadourian: Yes, quite a few. One was to add our new Rebuilding Rome feature. It uses a brand-new system that can be thought of as an evolution of AC2’s economic system. The RUS (Rome Upgrade System), as we call it, is quite a complex system, and what we had in mind from the beginning was the idea that it should give the player the pleasure of owning Rome by rebuilding shops and buying landmarks, for instance. So, in a way, everything had to be incorporated into the economic system. Also, rebuilding Rome would change the whole atmosphere of Rome; it would dynamically change the crowd composition at key moments of your progress. People become richer, less annoyed as you own more and more of Rome, and as the balance of power tilts in your direction. Another system that we built up from scratch was the system for the Brotherhood. Giving the player the opportunity to build a guild by recruiting citizens with good fighting potential was very exciting to do as a new feature, but tricky. The fact that you can summon them at pretty much any time demands answers to questions like: Who do we spawn? When? What sort of AI are they? What about upgrading them, the customization of their inventory, and of their looks, the contracts, everything UI-related, the Guild Management, and so forth. The result was awesome from an AI perspective and, thus, from a gamer’s perspective, too! Seeing those guys perform more significant deeds when you call them in-game is fantastic. They will make the difference in your game should you invest in them.

Was there a new game engine used?
Assadourian: We used the same AI engine that was used to create AC2. It allowed us to iterate quickly on both existing and new gameplay ingredients. For instance, we changed the archers to create gunmen and crossbowmen, which show quite a lot of differences with the previous implementation. They don’t drop their ranged weapon as you move close to them, and they move away from any obstacle to keep a line of sight with their target.

What was the main intent when creating this game in terms of aesthetic?
Pontbriand: We went location scouting in Italy three years ago for AC2. We already knew that we wanted to set the game in the Italian Renaissance, so Florence, Venice, and other Tuscan cities were a must. When we went to Rome, we instantly knew that this city, the sheer size of it, could support an entire game in itself.

With Assassin’s Creed, we always strive to be the historically accurate in the representation of the cities and the events that are in the game. Research is the foundation on which our work is based on, so long as it provides players a unique and entertaining experience. At the beginning of the production of Assassin’s Creed II, we did a lot of research on the Italian Renaissance and the 15th century in general. We studied the period through various media, such as books, TV series, and movies. Yet, I think we were most surprised that the Internet turned out to be a wonderful source of information—we found a lot of pictures, paintings, drawings, and maps that helped us understand and capture the feel and the history of the period.

As soon as Assassin’s Creed II was finished and released, our first step was to bring out all the material we had, especially the elements about the city of Rome, and chose what was relevant and useable for Assassin’s Creed: Brotherhood. Most of the details used in the production of Brotherhood come from pictures taken by the team during their initial trip to Italy. Yet again, drawings of the period found on the Internet helped us develop an idea of how to represent the landmarks during this period, since some iconic monuments have changed over the years. For example, Bufalini’s map of Rome (dated 1551) was chosen as our document of reference when designing the city’s layout. We actually imported the map into our engine and then scaled it until the size felt right.

Did the same team at Ubisoft that worked on Assassin’s Creed II work on this title?
Pontbriand: The Assassin’s Creed: Brotherhood team comprises a few hundred developers, many of whom had previously worked on AC1 and AC2, so they have a lot of experience with the brand and the game engine. This enabled us to work better and faster. Multiplayer has been in development at the Annecy studio for three years now, and we can’t wait for you guys to play it. It’s a really great experience, different from anything that’s out there.

Crowds are always a big part of Assassin’s Creed. How were they created for Brotherhood? Assadourian: We used our own engine. There are many aspects to creating the crowds. One of them is about finding who we spawn and when we spawn it. It has to be around the player, and it has to be done in advance. Another one involves what kind of AI is spawned. Some of the people in the crowd are performing their activity only during the day, others only during the night. Some of them are there both day and night (beggars, for instance). In order to achieve that, we have level designers painting the world where they want a crowd to spawn, and also establishing the crowd composition. We have an entire tool dedicated to making the crowds!