The Art Of: Assassin’s Creed II
Following up from our in-depth look at how Ubisoft Montreal is rebuilding the backstabbing open world adventure for its sequel, we talked with its art director, Mohamed Gambouz, about how he and his team have created its Renaissance Italy setting, from the the art decisions to the technology that enabled them. It turns out that it’s not all down to history books and baked light maps – game star Ezio’s free running and climbing capabilities all took a part in forming its visions of 15th century Rome, Florence and Venice.
Why did you choose Renaissance Italy as the setting for Assassin’s Creed II, and what challenges did this create?
When we created the Assassin’s Creed franchise, we knew we wanted to talk about pivotal periods in history – moments where everything changes and that redefine the world we now live in. This was exactly the case for Assassin’s Creed‘s setting – the Third Crusade. The period defined the balance of power between various civilizations and religions for the centuries to come.
So when we started Assassin’s Creed II, we asked ourselves, ‘What’s an even more exciting defining moment in history?’ The answer was easy to find. Within a short period of time and in a very precise place, a small number of geniuses such as Machiavelli, Leonardo Da Vinci and the Medici family, radically changed everything. The time is the end of the 15th century. The place is Italy and it’s what we now call the Renaissance, literally ‘rebirth’.
What challenges did this decision present?
The main challenge has been to recreate cities such as Florence and Venice. Obviously this requires lots of research. For example, there’s little information about what the Rialto Bridge in Venice looked like as it burnt down in 1524 – around the time our game is set. The only thing we knew is that it was made of wood, therefore, we designed the bridge based around the current bridge [built in 1591] but if created in wood.
In this regard, we’re lucky to have an architect with a master’s degree in history and theory of architecture on the team. She does all the historical research in terms of architecture, political events, and social aspects of the game. We are also in contact with Margaret Meserve, assistant professor of History at University of Notre Dame, who is reviewing the script and giving us advice on what we can and can’t do in order to ensure the game is as accurate as possible.
How did you approach recreating Venice, which is so immediately visually famous to people all over the world?
We realised from the beginning that gamers have high expectations in terms of playing in such a famous and beautiful place. It took us many iterations to come up with a satisfying and credible result. We focused a lot on exaggerating the postcard aspect of the city and tried to smartly spread this throughout the game’s environment to better reflect the image most players have of Venice.
When you considered making a sequel for Assassin’s Creed, what were the technical and artistic areas you wanted to push?
Because the game’s night and day cycle were the most important new visual feature, the first aspect we considered was the lighting. Previously, the sun was had been the main light source in the game and we had great tools to create the daylight. The addition of night scenes changed this since the main light sources at night are torches and lanterns.
To cope with these, we had to implement a new system called WorldLightMap. Its enables us to project textures: it paints the lighting instantly and directly projects it onto the environment and the people in the surroundings.
What principles did you use to compute such lighting?
We’re using baked light maps [pre-computed textures] instead of traditional omnis to simulate torches and lantern lighting, due both to the large size of our cities and the level of detail on our buildings. We’re also using a limited number of spots to cast shadows in indoor sections, and we baked ambient occlusion [a global shading technique] onto the geometry’s vertices.