In 2013, Epic Games teased the capabilities of Unreal Engine 4 with the Infiltrator demo. It looked incredible at the time, and you can still read the astonished comments from seven years ago on YouTube. Of course, now this sci-fi vignette only looks so-so. It's amazing how quickly incredible technology can become routine.

Well, here we go again: Unreal Engine 5 will be released next year, and Epic Games has a new PlayStation 5 tech demo called "Lumen in the Land of Nanite" to show it off (embedded above). Like the "Infiltrator" demo from 2013, it looks a bit unreasonable, with dynamically lit photorealistic caves and an entire collapsed city appearing at the end with no less detail.

With UE5, developers no longer have to worry about polygon counts, Epic said. Import a 3D asset consisting of hundreds of millions or billions of polygons, and the engine will do the rest, streaming the ultra-complex geometry at the highest possible level of detail.

This sounds like the kind of incredible propaganda that was occasionally seen in the 2010s. But according to Tim Sweeney, CEO of Epic Games, polygon count is really over as a measure of graphic fidelity.

"The philosophy behind this technology goes back to the idea of REYES (Render Everything Your Eye Sees) in the 1980s. It's a funny acronym that basically says that if an infinite amount of detail is available, it's the engine's job to determine exactly what pixels it needs to draw to display it," Sweeney said this week on a conference call with PC Gamer and others. 'Because some polygons are much smaller than pixels. That means you can render an approximation of that without missing any detail that you can perceive. Once you get to this point, you're done with the geometry. There is nothing more that can be done. If you render more polygons, you won't even notice them because the contribution of the polygons to each pixel on the screen is infinitesimally small."

Aside from looking cool, UE5's features are expected to make cross-platform development easier for smaller developers, allowing them to bring in just one set of high-quality assets. The engine handles all the necessary complexity scaling, right down to cell phones.

"If you have a custom-made asset like a statue, it's one thing to generate a high-resolution mesh, but then generating a mesh that works and looks good from different view distances is actually a pretty daunting task. It's a real challenge," said Kim Libreri, chief technical officer at Epic Games.

Even cinematic-quality assets can be used in UE5 games, and the technical demo was created primarily using Quixel Megascans.

"Nanite's virtualized geometry means that cinematic-quality source art consisting of hundreds of millions or billions of polygons can be imported directly into the Unreal Engine, from ZBrush sculpts to photogrammetric scans to CAD data. [The ability to use billions of polygons is amazing, but it doesn't mean that you can easily render movie-quality environmental scans. To achieve results like those in the tech demo, you'll need superior hardware, but it's within reach for today's gaming PCs.

"Rendering at this level of detail requires a variety of components," says Sweeney. One is the performance of the GPU and the GPU architecture to render this incredible amount of geometry." This requires a very large number of teraflops. The other is the ability to load and stream geometry efficiently. "

Will this demo run on my PC with RTX 2070 Super? For comparison, the PlayStation 5 GPU on which the demo video was captured achieves 10.28 teraflops, while the RTX 2070 Super achieves just over 9 teraflops. (Note that teraflops is not everything.)

Regarding loading and streaming, Sweeney said that the PlayStation 5's SSD architecture is "god-level" and "significantly more advanced than a PC," but that even with the NVMe SSD I am using " One thing's for sure, if you're not already using one, it's time to ditch the HDD.

"One of the big things we've done and are still working on with Unreal Engine 5 is optimizing for next-generation storage to make loading many times faster than current performance.

"This is so that we can bring in geometry and display it even though it won't all fit in memory.

Mr. Sweeney seemed surprised when I told him that until recently I had been loading some games from my HDD. I took the time to upgrade to an SSD-only system, but I'm sure I'm not alone. If you haven't completely switched over yet, be prepared for it to become obsolete in the next few years. It must happen eventually.

Also shown off in the tech demo: a new lighting technology called Lumen, a clever particle system that can mimic the behavior of a swarm of bats or a cockroach, the Chaos physics system, and ambisonic rendering (360 degree surround sound). All of these are said to work well with Nvidia's RTX ray tracing, but specific details about that and how Nvidia's DLSS may bring performance to UE5 games are unknown.

You will be able to start playing with this engine next year. A preview version of Unreal Engine 5 will be released in early 2021, with the full release expected later that year. Games made with the current version of the Unreal Engine can migrate to UE5 when the time is right, which Epic plans to do with Fortnite.

Use of the Unreal Engine will remain free, but Epic will also change its royalty policy. Retroactive to January 1 of this year, Epic will no longer collect royalties on the first $1 million in revenue from games using the Unreal Engine. Previously, Epic collected a 5% royalty on the first $3,000 in sales in a quarter.