The Witcher 4's leafy glory is all down to Epic's Nanite Foliage, and largely so is the fact it can run ray-traced at 60 fps on a lowly PS5

As the opener to an annual tech event, it's pretty hard to beat showing off what The Witcher 4 will look and run like in actual gameplay, but that's exactly what Epic and CD Projekt Red did for the former's keynote speech, State of Unreal 2025.

We all knew it was coming, of course, but sitting in a crowd of developers, creators, and journalists in Orlando, eardrums being blasted away with surround sound Ciri, it was clear that everyone wanted to be absolutely wowed at what The Witcher 4's developers had in store for us.

The thing is, we kind of knew that too, because rather than use its own RED Engine, CDPR switched had already announced its move to Unreal Engine 5 for The Witcher 4.

So I didn't think there wouldn't be anything that new to really show off. And, to a certain degree, that was very much the case, but there was one standout technological improvement Epic will eventually be bringing out with Unreal Engine 5.7, and one thing that looks to be making The Witcher 4's environment so dense, lush, and detailed, and it's Nanite Foliage. The first iteration of Epic's Nanite tech (a virtualised geometry engine) was for improving the surfaces of rocks, walls, and other large objects, and now it's all about leaves. Lots and lots of leaves.

What Epic and CDPR demonstrated with The Witcher 4 showed that Nanite Foliage is going to be a much more popular system. That's because it use voxels—instead of rasterized triangles, for handling leaves, needles, branches, etc—when the camera moves away, to a point where you can't tell that what was a highly detailed tree is now just a haze of blobs.

The voxels still get lit as part of Lumen and all generate real-time shadows, and the overall look is very convincing. At one point in the CDPR tech demo, the camera swoops down and rushes through a dense forest: at no point do you see any stuttering or lag or obvious LOD changes, just a seamless rush through countless trees.

Naturally, because it's all done using Nanite, the overall landscape, ground, lakes, rivers, and so on is just as fast and smooth. Letting the side down somewhat is the shadowing, as there are clear moments in the demo where shadows cast by trees and other objects popped into view, as the camera hurtled about. That might all be improved by the time The Witcher 4 is released, of course, but it might also just be a limitation of the fact that a standard PS5 was being used to run the demo.

Just a standard PlayStation 5, not a Pro, running the tech demo at a solid 60 fps with ray tracing. Given that the "main goal" for UE 5.6 is performance not necessarily pretties, that's pretty pleasing.

With the next chapter in the Witcher games aiming to be ray-traced and running at 60 fps on that particular platform, it bodes well for what the PC version might be capable of. That said, we thought about Cyberpunk 2077 and looked how that turned out.

In fairness, the 2077 one can play now is vastly superior to the game's original launch state, but perhaps with CDPR choosing UE5 for The Witcher 4, the developers will be able to focus far more on content, assets, gameplay, and optimisation, rather than just having to get the damned thing to work in the first place.

Anyway, the breakdown of what Epic's Nanite Foliage system will do garnered the biggest audience reaction of the whole Witcher tech demo, which could possibly mean that we'll see more open-world games in the future sporting truly epic scales of vegetation and all things nature-wise. Or should that be Epic scales?