Epic’s new game engine, Unreal Engine 5, is set to add a new suite of options and seemingly ease the process of game development for developers large and small. That ease of use, plus a drastically improved toolset and multiple features designed to save time for developers, could lead to development methods that look vastly different from previous generations.
But how poised is it to actually change the game development landscape? IGN spoke to a number of both AAA and indie developers to discuss what Unreal Engine 5 brings to the table and the possible ripple effects it could have on the industry. The picture these devs painted of the engine is one of efficiency, increased useability for spread-out dev teams, and the possibility of indie games being larger in scope than ever before.
Nanite
The biggest changes Unreal Engine 5 introduces include Nanite (Unreal’s geometry system), Lumen (its updated lighting system), and advancements in world and data streaming. These of course only scratch the surface, as Unreal 5 also includes changes to physics, fluid simulations, AI operations, character animation, and many more. But let’s examine those big three.
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.