Llorenç Marti Garcia

Hi! technical question, do you happen to know how these “volumetric fogs” are implemented?

Is it some sort of raymarching? SDFs ? Or mahbe rendered mesh in a secondary pass that extraxts the depth from the surface of the volumetric fog from the surface of the objects to compute the color of the fog on that pixel?

Any hint ?

#gamedev #diablo4beta #screenshotsaturday

Mar 18, 2023 at 10:54pmWeb
Show threadGnome KatMar 18, 2023

@llorens

Probably something using froxels. Just my guess.

https://www.ea.com/frostbite/news/physically-based-unified-volumetric-rendering-in-frostbite

Physically-based & Unified Volumetric Rendering in Frostbite - Frostbite

Talk by Sebastien Hillaire at SIGGRAPH 2015 in the Advances in Real-time Rendering course.

Electronic Arts Inc.
Show threadLlorenç Marti GarciaMar 18, 2023
@gnomekat Thanks! :D
Show threadJean-Sébastien GuayMar 18, 2023
@llorens @BartWronski wrote about it a while ago, good blog post, I encourage you to read it!
Show threadLlorenç Marti GarciaMar 18, 2023
@skylark13 @BartWronski Thanks! :D
Show threadBart Wronski 🇺🇦🇵🇸Mar 18, 2023
@llorens @skylark13 here's a link https://bartwronski.com/publications/ (scroll down, Volumetric Fog)
On my blog there are also some posts with implementation details, and an implementation on Github :)
Publications

Bart Wronski
Show threadLlorenç Marti GarciaMar 18, 2023
@BartWronski @skylark13 lots of thanks!! :D
Show threaddemofoxMar 18, 2023
@skylark13 @llorens @BartWronski I was one of two gfx programmers on this game for a lil over a year, saw this toot just now and was ashamed to not remember hehe. I'm glad bart wrote it up. Btw see if you can see the blue noise when the game comes out, or in screenshots. The video compression is eating it all up (not a bad thing!).
Show threadMike Wuetherick  Mar 18, 2023

@llorens
Unity uses local box volumes to define regions like this, internally it "voxelizes" the area to define fog regions and blends the edges

You can also use a 3d depth texture to define the fog but I have no idea how to generate one of those ;P

https://docs.unity3d.com/Packages/com.[email protected]/manual/Local-Volumetric-Fog.html

Local Volumetric Fog | High Definition RP | 14.0.6

Show threadLlorenç Marti GarciaMar 18, 2023
@gekido Thanks!!! :D