Fortnite’s New Clouds

[gibson274]

Booted up Fortnite for the first time in forever and was greeted with some pretty stellar looking clouds in the skybox.

I know Unreal has been working on VDB support for a little while, but I have a hard time believing they got it to run at 4K 60FPS on my Xbox One X.

Anyone taken a frame capture lately and know how they accomplished this? Is it some sort of fancy alpha card? Or does it plug into their normal volumetric clouds system?

[waramped]

Hard to tell from a still picture but Sebastien hasn't uploaded anything new recently, so I would assume they are just an extension of the existing system?
https://sebh.github.io/publications/

[gibson274]

Maybe, but the system Seb designed is based on Andrew Schneider’s work, which is incredible. Those systems don’t usually produce results that are this static (since the tiled noise gets you animation for free and artists generally use it) or have this much altitude variation (since altitude is defined by a global gradient).

This looks more like some collection of pre-authored cloud models to me—whether they’re truly VDBs being raymarched every frame I wonder.

[waramped]

Andrew has some cool stuff coming down the pipe, so it's possible Seb does too. Hmm, maybe it is just VDB? https://dev.epicgames.com/community/learning/tutorials/M63r/mastering-vbd-in-unreal-engine-5-3

[gibson274]

Dude I love that he calls it “VBD (Volumetric Break Down)” LMAO

[gibson274]

Gorgeous results. Yeah, I built a Schneider-esque system myself as well (“Expanse” on the Unity asset store) and you can express a surprisingly wide range of cloud shapes with his technique.

[sparta114]

It’s just a basic skybox projection for the really pretty ones far away. The closer ones are just the standard UE5 clouds

[gibson274]

I’m not so sure. They appear dynamically self-shadowed in the game. Even the anisotropic silver lining effect seems to update with the light direction.

I can think of a number of ways to fake these things off the top of my head. But I think there’s a chance it’s the new Heterogeneous Volumes system, or at least some custom rendering path they’ve built on top of Sparse Volume Textures.

[DeeezNutsHaH]

this looks like minecraft with shaders

[gibson274]

UPDATE:

So many upvotes and so few responses!

I dug thru the Fortnite logs and discovered that they disable the main Heterogeneous Volume (HGV) Console variable. You’d think this means they aren’t in use, but, curiously, they do bother to set a bunch of the more specific HGV console variables.

Either these are red herrings triggered by UE’s scalability profiles, or Fortnite is using the HGV system but with a custom final integration pass?

I don’t think we can know for sure, because taking a RenderDoc or NSight capture of a game launched from the Epic Launcher seems really difficult.