latest release for fm (fog machine)
tested to work on 1.21.6

install instructions

• download the zip and
• windows: hit win+r and paste in %appdata%\.minecraft\resourcepacks\ to navigate to that folder and place it there
• macos: place it in ~/Library/Application Support/minecraft/resourcepacks

different render distances have different effects on the fog, so you'll have to dial in the look using that