Epic Games' debut Unreal Engine 5 tech demo on PlayStation 5 gave fans a first look at next-gen graphical power, but all those pretty polygons don't tell consumers much about how the engine will affect upcoming games. A closer analysis of Unreal Engine 5's technological advancements and differences from current engines, however, shows how PlayStation 5 games could utilize Epic's system to improve player experiences.

The Unreal Engine 5 reveal was part of The Game Awards host Geoff Keighley's Summer Games Fest, a months-long stand-in for E3 and other summertime game expos cancelled due to the COVID-19 pandemic. The demo, titled "Lumen in the Land of Nanite," showed a woman traveling through a subterranean temple in the desert. According to Epic, the demo's titular Lumen and Nanite technologies are designed to save developers time by streamlining the steps between sculpting models and effects and shipping a finished game.

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In its demo narration, Epic spoke of "authored LODs," "baked normal maps," "ZBrush" and "specular illumination," all of which are likely nonsense to those not familiar with the ins and outs of game development. Here's Unreal Engine 5's new features, explained with the help of the folks at Digital Foundry.

How Unreal Engine 5's Improved Tech Can Affect Graphics & Gameplay

PS5 Unreal Engine

In the "DF Direct" video below, Digital Foundry's Alex Battaglia and John Linneman broke down the Unreal Engine 5 presentation to explain how Epic Games' new technology works on PS5 and other game systems. As Epic described, the most important element of Unreal Engine 5 is the Nanite system, which allows the engine to render billions of the triangle-shaped polygons that make up in-game models. This means Unreal Engine 5 games can be beautiful and detailed, yes, but it also provides a huge time-saver to developers.

Film-quality, high-poly models are normally sculpted first in the ZBrush design program as a baseline, then scaled down in detail until they're able to be properly processed by a game engine. Several models of varying detail levels are saved to be rendered when players are at various distances from the object, allowing better performance by making far-away models take up less processing power. Epic explained Unreal Engine 5 instead allows developers to directly import the high-quality models from ZBrush into the engine, and the engine then dynamically renders a number of triangles for each model depending on how many pixels it's taking up on screen. This saves developers time, as they no longer need to optimize models for performance, and it also theoretically eliminates pop-in effects - as Digital Foundry pointed out - since there's only one level of detail (the highest) per model in the game's files.

The Lumens feature is designed to create a similar ease of use for developers. It's a dynamic lighting tool that generates realistic lighting effects based on the location of light sources, shaping the light around polygons and bouncing it around spaces as it would in the real world. This theoretically means a light source can simply be created and placed in-game, and developers won't have to fine-tune (i.e. "bake") the lighting in particular scenes in order to make it look more real. Epic said these lighting effects can also react to changes in geometry, like when a cave roof collapses to reveal the sky above, so players could see next-gen lighting that adapts to their interactions with the environment (destructible buildings, etc.).

Related: PlayStation 5 Will Reduce Clunky Install Sizes With New SSD

All of this means games running on Unreal Engine 5 could be much higher fidelity and run smoother than other graphically impressive modern video games, and they could also feature visuals that adapt more to players' actions. It will be a resource-intensive engine, however, so Digital Foundry theorized not all developers might take advantage of Nanite-like "micro-polygon" tech, and it's still not yet clear how well Unreal Engine 5 will scale to lower-power devices (though Epic has said it will be able to). As reported by PC Gamer, a fast SSD is essential for rendering the kind of highly detailed scenes seen in the demo, and Epic's Tim Sweeney described the PS5's SSD as "god-tier" and more efficient than current PC SSDs. Sweeney also told The Verge Epic has been working closely with Sony on optimizing the engine for PS5's memory speeds. The Xbox Series X will also be capable of running Nanite and Lumens, but it seems Sony's console could be uniquely suited to take advantage of Nanite, as its much-hyped SSD will make loading the billions of triangles easier.

Next: PlayStation 5 SSD Won't Change Open World Games Dramatically, Despite Hype

The PlayStation 5 is set for a holiday 2020 launch.

Source: Digital Foundry