This is the Fogtools PLUGIN for PAPER - SPIGOT

YOU NEED THE FOGTOOLS MOD IN THE CLIENT TO WORK WITH THE PLUGIN

Client Mod:
https://www.curseforge.com/minecraft/mc-mods/fogtools

With this plugin you can set custom fog to players or @a, also it only works with OP permission level.

Server Commands:

/fogtoolsplugin set (player/@a) (radius) (density) (color) (sky) (opacity) (fade in) (fade out)

/fogtoolsplugin gradient (player/@a) (gradientshape) (radius) (density) (topcolor) (centercolor) (bottomcolor) (sky) (opacity) (fade in) (fade out)

/fogtoolsplugin clear (player/@a)

Also it have a new command that only work on servers!

BIOME COMMANDS:

/fogtoolsplugin biome (gradient/set/clear/list) (biome) (....)

Biome commands work so that if a player enters or leaves a specific biome, a fog is automatically placed on them.