Volumetric fog

FogLayer fills the low air with drifting ground fog that wraps around buildings, roofs, landmarks and trees, tinted by the theme and glowing toward the sun:

import { FogLayer } from 'maplibre-landmarks';

map.addLayer(new FogLayer({ id: 'fog' }), firstSymbolLayerId); // after the other 3D layers

Option	Default	Description
density	0.6	Thickness (setDensity to change live)
height	40	Fog thickness above the ground (or the valley floor with terrain)
altitude	—	With terrain: absolute fog top in metres (overrides height)
coverage	0.65	0–1: scattered banks to a full blanket (setCoverage)
wind	{ speed: 2, direction: 270 }	m/s and bearing it drifts toward (setWind)
slices	32	8–64; more is smoother and costs fill rate
radius	auto	Metres around the map centre that get fog (default grows with the view)
color	theme	CSS colour override
horizonHaze	true	Also tint MapLibre's sky fog toward the horizon
minZoom	12	Below this zoom nothing is drawn

The fog is drawn as camera-facing slices tested against the depth buffer, so buildings and mountains hide the fog behind them. On flat maps it lies on the ground; with terrain it pools in the valleys up to height above the lowest ground near the centre (or up to altitude), with ridges and peaks rising out of it. It never covers labels. setHeight, setAltitude, setDensity, setCoverage and setWind change it live.