How Ubisoft built the world of Assassin’s Creed: Shadows | Pierre Fortin interview

When Assassin’s Creed: Shadows comes out this fall, players should notice a world full of more dynamism.

That’s one of the things that the world builders at Ubisoft’s development teams prioritized in creating the 3D environments of the Japanese setting. These aren’t just scenes that are like pretty postcards. They’re more dynamic and alive, according to Pierre Fortin, technical architect at Ubisoft. The world is a full-on simulation, not just a partial world like on a Hollywood movie set.

Assassin’s Creed: Shadows comes out on November 15 on the PC and consoles. I spoke with Fortin about the game’s 3D world in ancient Japan and the Anvil game engine that the French video game publisher used to create it. A 20-year veteran at Ubisoft, he has been the technical architect since 2020. He worked on games such as Assassin’s Creed: Origin, Immortals: Fenyx Rising and Assassin’s Creed: Syndicate.

We talked about the Anvil game engine, computing budgets and tech like dynamic resolution across the platforms. It was good to catch up on the state of the art for 3D imagery in high-end triple-A games. We talked about tech limitations, like how many characters can be in a crowd in the game. And Fortin said Ubisoft constantly tries to improve visual realism, like how a character blends into the background.

Here’s an edited transcript of our interview.

GamesBeat: Can you tell me about your background? How long have you worked on Assassin’s Creed?

Pierre Fortin: I’ve been at Ubisoft close to 20 years. I started at the studio in Quebec as a programmer. I worked on almost all the games developed there. I started my career with Assassin’s Creed on Syndicate, but I worked on other games before that. I helped out on Origin and on Immortals: Fenyx Rising. I’ve always had more of a technology-focused background, working on things like the animation system. I’ve been the technology director since 2020.

GamesBeat: The Anvil engine, can you tell me about the origins of that technology?

Fortin: Anvil started way back on the first Assassin’s Creed. That’s the first game made with Anvil. It’s been continuously evolving through all of these games. I like to use the ship of Theseus metaphor. Not much of the original Anvil still exists today. It’s developed continuously to get to where we are today. There have been several big leaps and advancements on the tech side. For example, whenever we do a new generation in terms of consoles, you can expect lots of new systems coming in. That’s the case with Shadows.

GamesBeat: What’s it like developing and improving an engine while developers are using it to make games at the same time? Do you ever have a period of time where the technology development takes precedence over using the tools to work on new installments?

Fortin: Typically how it works is that in production we have several stages. We have a stage of pre-production where we have lots of meetings with art directors and story directors to figure out where we’ll go next with our games. We develop the engine based on what we want to see in the games. We’ll decide on what innovations we want to carry over. Then we start work on that, entering a production phase, where typically most of our systems are ready, but we keep moving them forward while we can during production. Sometimes that means some systems aren’t used to the full extent, but they’re still workable.

Often we’re working a bit in advance of the production teams, but we work with them to the end. When you have lots of content that gets produced for the game, you can see where you need to optimize, what you need to work on to make sure everyone gets where they want to go. We follow the production pretty much the entire time. We’re the first in and last out, you might say. We’re the last one on the project, making sure all the bugs are ironed out in the new systems we’ve developed.

GamesBeat: Why has Ubisoft always used its own technology for Assassin’s Creed, rather than Unity or Unreal Engine 5? Is there something in Assassin’s Creed itself that relates to why you use Anvil?

Fortin: It’s a complex question. The first thing is the production of the games. If you look at Shadows, we have close to 17 studios working with us. I’d have to confirm the exact number, but I think it’s 17. To be efficient in producing a game like that on a 24-hour cycle, five days a week, you need to tailor your production pipeline and your engine to that cycle. We spend a lot of time optimizing not just the game itself, but how our production works, the tools we develop. We build our engine tailored to Ubisoft’s production capacity.

That’s the production side. On the game side, we want to be able to push the tech where we want our games to go. If you look at Shadows and the major pillars we’ve added, dynamism is a good one to take as an example. Early in our discussions around art direction, we knew we wanted to move from a beautiful postcard to a beautiful movie. Investing a lot of time in, for example, how vegetation moves, how the characters react to wind, all that stuff. We implemented new systems like seasons. If you don’t control your own technology, that kind of thing is harder to do. We might not be able to give our production teams the artistic freedom that we want.

GamesBeat: Is it fair to say that there’s a given computing budget that a game can use, and that an engine can optimize exactly how that budget gets used? If you’re building a game like Life is Strange, you have a certain approach to how the characters or the environment are going to look. You can sacrifice things like the speed of interaction. Would you say that’s a difference in the engine?

Fortin: It is, definitely. That budget you describe, we have to arbitrate where we want to spend it, basically. For Assassin’s Creed, we want to have the most credible environments. We spend a good chunk of our GPU budget there. Our CPU budget is spent on things like crowds that have lots of different people, lots of animation. That’s part of the equation.

You could argue that you can take an engine and create different profiles for spending the budget within it, but that takes time. On each iteration of your game it would have to evolve. That’s another reason we keep iterating with Anvil, because we further refine our recipe in terms of the tech budget over time. That’s definitely something we think about as we develop and tweak different systems.

GamesBeat: When it comes to the differences between consoles and high-end PCs, does the engine automatically figure out now what quality the hardware can deliver? I don’t know how standard or baked-in this dynamic resolution can be.

Fortin: Dynamic resolution is interesting. It allows automatic scaling of performance, but we also have other levers of performance that we expose. A PC will typically have more scalability options to select from. Dynamic resolution is one of them. We use dynamic resolution to maximize–you might call it a return on investment per pixel. Sometimes you need to run a lot of computation to output a certain pixel value. It’s more costly. When you compound that into a whole frame you have a nicer image, but the expense of that means we need to render at a lower resolution. We then use dynamic resolution to push it further.

Typically we try as much as possible to not have to rely on dynamic resolution. We want to be optimal. But we can use dynamic resolution in certain cases. It’s not the only lever we have. We have several levers of performance. Dynamic resolution only helps, for example, with the GPU. It doesn’t help with the CPU. For CPU-intensive tasks we need to rely on other techniques to make sure that the game is scalable across a wide range of hardware.

GamesBeat: Looking at crowd size and how many characters you can have in a scene, what affects that?

Fortin: There are several considerations around crowd size. It comes down to what your game wants to do with the crowd. It’s not always a matter of just not being able to render thousands of NPCs. It’s adding gameplay that’s fun with thousands of NPCs and having that crowd react appropriately. I’d say the biggest thing with massive crowds is the CPU cost. You have all of these characters that need to be animated, that need to be rendered, that need to be physically driven. Different games will make different choices. For Assassin’s Creed, the crowd is something important for us. We spend a good chunk of our CPU budget on making it possible. It’s something we optimize for.

GamesBeat: What is different about what you get from this generation of Anvil versus previous generations?

Fortin: If you look at Shadows, one of the pillars we have is dynamism. That translates into a lot of the technologies we developed. The dynamism you see on the screen is what stands out. All of this tech ultimately allows us to reach the vision we had when we started working on Shadows. That was, as I said, moving from beautiful postcards, super-nice static screens, to something that was more dynamic, a beautiful movie, with much more animation on the screen. The dynamism we pushed on Shadows is what stands out compared to our previous titles.

GamesBeat: Blending the different 3D objects into a scene–sometimes you can tell, especially in older games, the gap between the background and the character. Is that as much of an issue as you’re trying to perfect the relationship between the character and their immediate surroundings, versus the more distant background?

Fortin: That’s something we’ve always tried to improve. If you saw the presentation at Gamescom, part of it was about what we call virtual geometry. This is a direct response to that. As you say, there are things in the background and things in the foreground. It’s what we call level of detail. Previously we had fixed level of detail. If we made a building, there would be versions of that with low resolution, medium resolution, and high resolution. Now we have something that covers that whole spectrum dynamically.

When we use that technology, which we introduced on Shadows, you can expect to see, for example–you’ll always see the nicer side of a building. The level of detail we push will always be the most we can given the angle, the draw distance, things like that. Addressing that distinction you talk about is a constant focus in open world games. You can go between seeing something from two kilometers away to maybe 10 meters. That’s a strong focus for us.

GamesBeat: When you go on something like the Universal Studios tour, you get to see the facades on movie sets. In games, do you have to fully build out the 3D world, or do you only build out what we can see? Are you able to have something like a half-built building because we only see one side?

Fortin: For an open world we need to build the whole thing, from all angles. If you have a more corridor-based game, designers can definitely rely on those sorts of tricks. But for a game like Shadows, we model the entire environment. The world is fully modeled, created by a team of great level artists. It’s a full simulation.

GamesBeat: You have a mix of small teams and large teams that are working on this kind of technology. What would be your advice for the smaller teams? What should they do with their more limited manpower?

Fortin: I’m not sure I can answer. Open world games are a big endeavor. I work with a super talented team of programmers and artists. It’s a genre that still requires a larger team. At Ubisoft we spend quite a lot of time crafting our production pipelines to build these kinds of worlds. It’s a significant investment. We’re very good at creating open world environments.

GamesBeat: In what way is Assassin’s Creed: Shadows’ open world differing from previous AC open worlds?

Fortin: With Assassin’s Creed: Shadows, we wanted to continue to push the boundaries of visual fidelity and immersion to create a world that feels more immersive and realistic than in any previous AC game.

To achieve this, the team placed a lot of emphasis on world’s responsiveness and dynamism, introducing new ways to interact with the world, for example through environmental destruction, but also with the introduction of dynamic seasons system, adding new variables in addition to weather and time of day when navigating the world.

We also wanted this dynamism to go beyond player immersion and have a meaningful impact on the gameplay. For example, lightning and rainstorms can spawn, covering you in darkness and wet conditions, to mask your approach on enemies or tricky areas.

This is only an example, and we cannot wait for you and players to be able to try to game and experience this world for themselves.