Unreal Fest 2025: The Witcher 4 and UE 5.6 – all the important info at a glance

Unreal Fest 2025 is in full swing. Epic Games is not only giving a glimpse of the graphical splendor of The Witcher 4, but also letting Unreal Engine 5.6 off the leash.

Unreal Fest 2025 kicked off today in Orlando. Naturally, the developers at Epic Games were focused on the new features of Unreal Engine and The Witcher 4, which had already been announced ahead of the festivities.

The Witcher 4: A technical demo in Unreal Engine 5.6

The absolute highlight of the State of Unreal keynote was undoubtedly the demonstration of The Witcher 4

Unlike previous announcements with pre-rendered trailers, CD Projekt Red and Epic Games presented scenes from the current state of development of the game.
However, it should be noted that the images shown are a technical presentation in the context of Unreal Engine 5.6 and not actual gameplay, as CD Projekt Red explains in the accompanying announcement.

The tech demo took players to the previously unknown region of Kovir, where protagonist Ciri travels through snow-covered mountain landscapes and dense forests with her horse Kelpie.

Unreal Engine 5.6: Focus on performance and open-world development

Alongside the Witcher demo, Epic Games announced the immediate availability of Unreal Engine 5.6. According to the announcement, the new version focuses on optimizing open-world games and achieving consistent 60 FPS performance on current console hardware.

Lumen optimizations

One of the most important improvements concerns the lumen system for global illumination:

According to Epic Games, the hardware-based ray tracing implementation has been fundamentally redesigned to eliminate CPU bottlenecks.

The optimizations are intended to bring the hardware ray tracing variant of Lumen up to the performance level of the software-based solution, freeing up corresponding CPU resources for other systems.

“Fast Geometry Streaming Plugin”

Another key feature of Unreal Engine 5.6 is the (still experimental) “Fast Geometry Streaming Plugin.”

According to the developers, this system allows large amounts of static geometry to be loaded faster and with more consistent frame rates at runtime.
For open-world games, Epic Games promises smoother transitions between different areas without annoying loading times or frame rate drops.

Renderer parallelization and more

The Render Hardware Interface (RHI) has been extensively reworked to better utilize the multithreading capabilities of modern hardware. Previously, certain rendering operations were limited to the render thread, even though current graphics APIs such as DirectX 12, Vulkan, and Metal support parallel processing. These limitations have been removed in version 5.6, as Epic Games explains in the release notes

“MetaHuman Creator,” Epic’s tool for creating photorealistic digital humans, has also received fresh updates. The system is now directly integrated into the Unreal Editor and offers new parametric body systems and improved visual quality.

MetaHuman is used in The Witcher 4 to render NPCs, giving even minor characters a high degree of realism.
The new MetaHuman Animator, on the other hand, enables real-time workflows for facial and body animation.

Another aspect of the Witcher 4 demo was the dense vegetation in the forest areas. This is made possible by “Nanite Foliage,” a newly added extension to the Nanite virtualization system. The system is designed to render extremely detailed trees and plants in large numbers without any loss of performance.

Nanite Foliage also solves problems with dynamically moving objects such as swaying trees and improves integration with the Lumen lighting system. However, the full version of this feature is not expected until Unreal Engine 5.7.