Yesterday, Swedish developer Coffee Stain Studios released Update 8 on the Experimental branch of its highly successful factory building game Satisfactory, upgrading the game from Unreal Engine 4 to Unreal Engine 5. This effectively makes it the first third-party game to support UE5, just ahead of today's release of Layers of Fear.

　　The engine upgrade comes with a lot of technical improvements, taking advantage of the World Partitioning system to improve level streaming and reduce hitches while traversing the open world, exploiting the Chaos physics simulation system to drive vehicles, adding Unreal Engine 5's own Temporal Super Resolution upscaling, and even converting part of the game's content (specifically Rocks, Cliffs, and Conveyor items) to support the new Nanite virtual geometry system.

　　However, by far the most impactful change from a visual standpoint is the switch to Unreal Engine 5's Lumen global illumination lighting. It is currently disabled by default (even when selecting the Ultra graphics preset) because of the increased strain on performance, though you can reduce that by disabling the Lumen reflections in the graphics settings.

　　That would still leave the high-quality bounce light system in place which, as showcased by YouTuber TotalXClipse in a comparison video between Lumen and the previous lighting system, is simply glorious. ResetEra user Lant_War also shared many comparison pictures; I've embedded them below.

　　Lumen OFF

　　Lumen ON

　　Lumen OFF

　　Lumen ON

　　Lumen OFF

　　Lumen OFF

　　Lumen ON

　　Lumen OFF

　　Lumen ONThey say pictures are worth a thousand words, but let's try to unpack it anyway. On the one hand, it is immediately obvious from the first image comparison that Satisfactory players will need to properly place lights in their interiors now since they won't be unrealistically lit as before. That tends to result in darker visuals. On the other hand, after placing enough lights around (or simply going outside), the lighting bounces around the scene in a way that singlehandedly makes the visuals look more grounded and realistic, regardless of the game's artistic style.

　　This isn't even the full extent of the potential of Unreal Engine 5's Lumen. Coffee Stain Studios didn't say anything about supporting hardware ray tracing, which means they're using the default software ray tracing based on Mesh Distance Fields. As explained by Epic in UE5's Lumen documentation, hardware ray tracing can achieve far better quality thanks to its support for tracing against skinned meshes. Additionally, Lumen with hardware ray tracing adds Far Field traces, which expand the Global Illumination (and Reflections, if enabled) to one kilometer. In contrast, the software based solution is set to 200 meters by default.

　　With even more triple-A studios switching to Unreal Engine 5 from their internal engines (Crystal Dynamics and CD Projekt RED, for instance), the usage of Lumen and Nanite is only going to become more ubiquitous. Let's hope that more of the countless UE4 games opt to switch to UE5 like Satisfactory, Payday 3, and others have chosen to do. The visual payoff is massive.