What Unreal Engine 5 Means for the Games Industry

Nanite promises “limitless geometry.” And while that may sound like the 9th circle of hell to those who shared my experience in high school, it actually means that full quality assets, containing millions of tiny triangles can be created or imported to Unreal 5 with tiny hits to performance compared to before.

According to Studio Technical Director at The Coalition (Gears 5) Kate Raynor in a recent Xbox Wire, Nanite “enables full-quality movie assets to be rendered in real time. This means that our artists can create assets with tens of millions of polygons, scalable to scenes with billions and billions. The details are just incredible, more than 100 times what was possible before.”

In previous Unreal Engines, placing objects with massive geometric detail in the middle of a scene could lead to intense slowdown and a tanking framerate. As Chief Technology Officer for new AAA studio That’s No Moon, Barry Genova, told IGN: “Nanite opens the ability to use highly detailed geometry while maintaining good runtime performance.”

In Epic’s engine showcase video, Lumen in the Land of Nanite, you can see the massive amount of detail broken down to the actual triangles. You can also see the same in The Matrix Awakens: An Unreal Engine 5 Experience, and even toggle the triangle view on and off yourself.

You couldn’t work easily with objects that had this level of detail before Unreal Engine 5, and the workaround in older engines is mostly two-fold: normal mapping and authored LODs, or levels of detail. Normal mapping involves taking a custom, highly detailed 2D texture, and wrapping it around a lower detail object. Think of the face swapper in the Mission Impossible movies, or the movie Possessor, if you truly would like to have nightmares forever.

It allows developers to achieve textured detail without breaking the bank when it comes to resources, whether those resource constraints are the target hardware devs hope to ship on, or even the budget of the game, as removing extra steps can save tons of time and money.

Custom LODs allow high resolution and low resolution versions of the same in-game asset to dynamically swap with each other based on the player’s distance, or line of sight to the object. A developer could let you see the best version of an object as you examine it from three inches away, but including that same asset far off on the horizon would simply be a waste of resources, as the engine would have to work to maintain that level of detail while it’s not even possible to see. This was all done manually in previous engines, as developers had to create these extra assets and tell the engine when to use them.

Both of these solutions, among many others, were creative workarounds to unavoidable problems, but Epic claims to fix them with Nanite. Nanite allows the developer to place the highest quality asset possible, with massive amounts of geometric detail, without worrying about faking it with normal mapping or papering over the cracks with custom LODs. Indie developer Dan Kim Nguyen praised this element of UE5, and told us that “it’s a game changer.”

“Any environment assets I create are less likely to cause performance issues when brought into UE5. I worry less about poly counts [or the level of detail], for assets. This gives me more freedom as an environment artist to create more realistic assets.”

Unreal’s website claims it achieves all this by “[Intelligently doing] work on only the detail that can be perceived and no more,” by handling LODs without the extra steps of having to create and tell the engine when to use them, and by streaming its data much more efficiently. And this isn’t only going to help resource-constrained indie devs, as Bloober Team (The Medium, The Blair Witch Project) Lead Programmer Mariusz Szaflik explained.

“Multiple orders of magnitude increase in geometry complexity is a huge game changer for us,” he said. “Artists are less constrained by polygon budget, could work faster and be more creative. Of course, Nanite is not a holy grail that will allow artists to put whatever they want into the game world, but certainly, it can smooth asset related pipelines and increase productivity/visual fidelity…”

These detailed assets can either be custom-made, or imported from the Quixel Megascan library, a huge repository of assets available to pull from inside Unreal 5 using Quixel Bridge with just a drag and drop. But detailed geometry wasn’t the only thing slowing down developers; lighting was also very cumbersome in previous engines.

Which brings us to Lumen.

Lumen

Lumen is Unreal 5’s “fully dynamic global illumination and reflections system.” Much like Nanite, Lumen promises to save on development time and to maximize resources. Travis Johnston, Director of Technology for ProbablyMonsters (whose team Firewalk is working on a new multiplayer IP for Sony), told us why that’s so useful.

“Literally everyone at the company has been waiting for this,” he said. “Most importantly, artists are beside themselves as they no longer have to make tradeoffs of either reduced lighting quality or slower workflows with delayed results. Designers no longer need to choose between the amount of dynamic environments in the game vs. the overall lighting and shadow quality.

Engineers no longer have to set up and maintain lightmap farms that slow down builds and can suddenly fail during important milestones. Lastly, the finance people at small companies no longer need to make capital investments in lightmap farms just to get decent-looking demos out the door. Gamers now get worlds they can interact with and modify that still look amazing for even better immersion. Literally everyone wins, so we expect the visual bar on games to jump very quickly in the next year.”

Lumen also works hand-in-hand with Nanite, as high detail geometry would be wasted without high detail shadows and lighting. “Diffuse lighting,” or indirect lighting that often bounces off multiple sources is now dynamic, much more accurate, and less resource-intensive, as it can all be handled in-engine without a lighting artist performing multiple render passes or “baking” light to check the look of their scene.

This interactivity with geometry also has dynamic in-game consequences, as Lumen in the Land of Nanite shows during its cave section. In that demo, the lighting that was hitting the outside roof of the cavern is allowed to shine through once the geometry is broken, creating a hole in the structure.

In older engines, this would be a scripted section with pre-baked lighting that would require specific instruction and rendering passes by a lighting artist. “Lumen and Nanite have changed the way we think about content creation,” said Szaflik, “and now some things (like fully dynamic environments) are easier to create than ever before.”

But Lumen and Nanite, although possible game changers on their own, wouldn’t make as much of an impact in giant open worlds if Unreal 5 didn’t change how the engine handles data across those immense spaces. For that, Epic created World Partition.

‘World Partition’ and ‘One File Per Actor’

World Partition is, essentially, a new system that makes it much easier to build large open worlds. While “data management” isn’t the sexiest term to the outside observer, World Partition has the potential to be one of the most important features for both AAA and indie studios, as it automates much of what makes open worlds currently so hard to manage. The potential to streamline the creation of open worlds particularly excited CD Projekt Red (The Witcher 3, Cyberpunk 2077), explained its Chief Technology Officer Paweł Zawodny.

“Broadly I think one of the things I’m most excited about when thinking about the wider industry is the availability and accessibility of technology to create open worlds,” said Zawodny. “Large scale open worlds historically have required a lot of investment and resources, and are hard to make with smaller teams.

“They can be complicated and a massive challenge for independent studios who simply don’t have hundreds of developers on staff. But with Unreal Engine 5 putting a big focus on open worlds, I think you’ll start to see smaller developers taking on open worlds and seeing what they can do in that space.”

Unreal Engine 5 – Official Release Images

World Partition does the work of dividing your giant open world into smaller levels – behind-the-scenes, of course, not in the act of actually playing – so the game is only loading what it needs and not breaking the performance.

This not only helps with performance, but workflow as well. Both representatives from Bloober Team and ProbablyMonsters mentioned a new feature inside of World Partition by name: “One File Per Actor,” or OFPA. In older Unreal Engines, if you wanted to make changes to a particular file, it could lock another developer out of what they were doing until you were done, slowing everybody down. OFPA lets a developer work with a very small, partitioned building block of the level without affecting anyone else’s work, drastically easing the workflow for everyone.

In Johnston’s Words, “many conflicts over source control exclusive check-outs have all but gone away and team members can no longer accidentally hold each other up.” This new data management system is especially important in a post-pandemic world where many devs are no longer occupying the same physical space and can’t be asked to please log off for the twelfth time so everyone else can get their work done.

Workflow

There will be games that look incredible in large part because of these new tools, but again and again, the answers we received from devs about the features they were most excited about were ones that improved the efficiency of their workflow. Developers can theoretically focus on what they want to do in the first place: spending less time fiddling with tools, and more time making games fun, a process called “iteration” that requires tons of trial, error, and time.

The process of iteration is so important, that several developers mentioned it by name, especially as it pertains to the “gameplay loop,” or what the player will be doing over and over again while playing their game. If that core loop isn’t fun or enjoyable in some way, then what’s the point?

In that previously mentioned Xbox Wire, Rayner said “UE5 enables developers to take the handcuffs off and truly create the content we’ve always dreamed of making. No more compromises! It also creates the removal of friction points in workflow… UE5 has rapidly increased our iteration time because working within the engine is a what-you-see-is-what-you-get experience. There is no more guesswork. The tech is all there, and now all we have to do is familiarize our content creators to it.”

Unreal 5 promises to make developers’ lives easier. With ballooning budgets, expanding production timelines, and an increasingly remote workforce, anything to ease the pipeline will theoretically lead to more time in the playtesting and design phases. But this newfound accessibility when it comes to using lifelike assets doesn’t come without caveats. Bruce Straley, co-creator of The Last Of Us, addressed the general advancement in development tools in a recent tweet, saying that aesthetic distinction is a must.

“Now that realistic graphics are at every devs’ fingertips, stylization & art direction is going to be essential to stand out from the crowd,” tweeted Straley. “Good art directors, creative artists & artistically-minded rendering engineers are needed now more than ever… Likewise for gameplay systems: the more compromises to dynamic, interactive, responsive experiences made in order to [achieve] photorealistic graphics, the further we get from actually achieving integrated, “realistic” gameplay experiences.”

With Nanite, Lumen, World Partition, and a more efficient pipeline, Unreal Engine 5 appears to give developers more power over the scope, look, and mechanics of their games than ever before. “Unreal Engine 5 is going to continue to push the quality of all games higher,” said Genova. “Unreal allows teams to focus on the game instead of having to spend a significant amount of time building up all the framework and infrastructure of an engine.

“It showcases what is possible providing inspiration — even for games not made with Unreal Engine. Developers have more time to research, innovate, and iterate on the gameplay providing a wider variety of experiences for all the players. It is net-win for everyone.”

Ronny Barrier is a Gameplay Producer for IGN.