Assassin’s Creed Shadows’ new technology increases environmental immersion

Assassin’s Creed Shadows, the next game in the beloved franchise, will differ from its predecessors for many reasons. But the two things that will set it apart the most are that the new game will finally be playable in Japan — and that it’s the first in the series designed after the PS4 and Xbox One eras, so they’re going all out on graphics. Ubisoft says that technical advancements in its Anvil game engine will give AC Shadows the most immersive environments in the series yet.

That doesn’t just mean gorgeous locations and buildings befitting the late 16th century Sengoku period of Japan, where and when the game is set. During presentations and interviews I attended during and after Gamescom in Cologne, Germany, Ubisoft’s technical directors explained how the new tricks in the Anvil engine powering the game make players feel like they’re walking around a richly realized world full of dynamic weather and procedurally generated conditions, from the clouds in the sky to the dust beneath your character’s feet.

It even applies to anything in front of the player’s sword: if you cut through bamboo trees, they will fall in the path your katana has traveled.

“When we started looking at what we wanted to do with AC Shadows, we often said we wanted to go from a nice postcard to a nice movie, in the way that we produce super beautiful images and things like that, AC Shadows technology director Pierre Fortin said. But in this game, he continued, “we want to show something that’s a little more in action and more dynamic on the screen.”

Small details unite into a storm of immersion

Ubisoft believes this will dramatically improve immersion, and at the closed-door Gamescom tech presentation I saw, I was impressed by the efforts made to replicate the way trees, light, weather and rain look in real life. It got to the point where the voice of the presenter, AC Shadows art director Thierry Dansereau, was drowned out by wind whistling through trees and water splashing through gutters, with images of light splashing through leaves in a bamboo forest and snow flurries dusting snowflakes around characters’ feet.

It’s these little details – “everything that happens in everyday life but that we don’t pay attention to,” as Dansereau calls it – that will passively guide players in AC Shadows and make them more immersed in the game than in other games.

“Now if you can translate that into a video game experience, [players] “The brain perceives it as reality in a certain way,” Dansereau said.

This dynamic environment isn’t just for looks — it affects how you play, the directors explained. The weather in the open world changes as time passes, so you might want to wait for a nighttime rainstorm to sneak into a castle town, where the stormy noise and curtains of rain limit the ability of guards to detect players. That works both ways: Fog on a humid summer day or a snowstorm might help you hide, but winter weather might freeze a lake over, making it impossible to stealthily swim toward a building. These are among the many procedurally generated variables that make the world unpredictable — and therefore more immersive, Dansereau said.

Since AC Shadows isn’t releasing with last-gen compatibility for PS4 and Xbox One, the team was able to push the Anvil engine onto PS5, Xbox Series X, and PC. Shadows features ray tracing to make light sparkle on the surface of koi ponds and rivers, but the team also did a lot of research, pushing their lighting tech to add layers of weather particles that capture just the right flavor of light in Japan.

“There is a lot of light that shines through the fog and mist, creating that Japanese light that everyone talks about, including people who travel to Japan,” Dansereau said.

Technical advances in the Anvil engine mean that many more objects are rendered, far beyond the player’s sightlines, minimizing the number of poorly rendered pre-rendered objects that loom in the background. Like other under-the-hood improvements, this one is better when players don’t notice it, Dansereau says: “So maybe some people will never notice most of the features that we put in there because it blends so seamlessly. So if that’s the case, it’s perfect.”

As mentioned, the game features dynamic environmental destruction — while playing as the shinobi Naoe or samurai Yasuke, your sword strokes will slice through bamboo trees, bushes, paper doors, and the like in the patterns your blade creates. This, too, required technological advancements to slice objects in different ways and directions — something done specifically to make the feudal Japan setting seem more lifelike.

“We wanted to make that fantasy of a super sharp sword come true,” Fortin said. “We pushed the technology in that direction to present a Japan that is more believable.”

How much AI is in AC Shadows?

Back in 2020, Fortin explained in the official blog for Epic’s Unreal engine that the increasing amount of data for modern games, including Assassin’s Creed Origins and Odyssey, posed a challenge for developers. At the time, he looked to advancements in machine learning and artificial intelligence to synthesize that massive amount of data and help do some of the tedious animation work, freeing up animators for areas that require human craft and input.

And despite the skyrocketing use of AI in technology and its expansion into gaming, Fortin says that not much was used in the development of AC Shadows. As he predicted, one advancement for AC Shadows was the use of a lot of procedural generation to do things like populate the world with everything from large trees and buildings to pebbles at characters’ feet that are generated on the GPU as players play — and changing it based on the in-game season. In the past, this wasn’t possible because one set of data (in simplified terms) was pre-loaded into the game’s data.

“Now that we have that deck of GPU scattering, we can, for example, [propagate] “We can change the world dynamically with different types of assets, given that you’re playing in winter, summer or spring,” Fortin said.

When cited for his 2020 article, he thought the industry would see an increase in AI-assisted human procedural generation, as Fortin described, but ultimately no so-called generative AI technology was used in AC Shadows.

Bigger games, better ray tracing tricks and more

There are other ways the Anvil engine’s advancements will impact what players see in AC Shadows. Fortin was right about the proliferation of game data complicating game development, but it turns out some new technology is helping to solve that. Ray tracing, for example, refers to the rendering of light on reflective surfaces, and the team built a global lighting system that ultimately removed steps in the game’s production pipeline.

The AC Shadows team was able to move the ray tracing global illumination system, which was CPU intensive during builds, to processing while the game was running. This had the added benefit of freeing up developers to make changes around the player on the fly while the game was running.

“For example, by introducing a system like ray traced global illumination, we can destroy objects in AC Shadows and see how the light around those objects changes dynamically,” Fortin said.

In short, players get better lighting and developers can keep up with the increasing complexity of the games they make.

From weather flowing around players to objects being destroyed by their swords, AC Shadows has a host of improvements under the hood that make it the most advanced Assassin’s Creed game ever.

We’ve heard all these claims about dynamic weather and conditions in games in the past, so it’s nice to see presentations showing off how this technology works in real-time, along with details from the directors who created it. We’ll see if it all works as promised when Assassin’s Creed Shadows launches on November 15, 2024.

Check this out: Gamescom Opening Night Live Recap

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