code · pull · Jan 4, 2026 · Jan 4, 2026
diff --git a/examples/files.json b/examples/files.json
@@ -332,6 +332,7 @@
 		"webgpu_depth_texture",
 		"webgpu_display_stereo",
 		"webgpu_equirectangular",
+		"webgpu_fog_height",
 		"webgpu_hdr",
 		"webgpu_instance_mesh",
 		"webgpu_instance_path",

diff --git a/examples/screenshots/webgpu_fog_height.jpg b/examples/screenshots/webgpu_fog_height.jpg
diff --git a/examples/webgpu_fog_height.html b/examples/webgpu_fog_height.html
@@ -0,0 +1,148 @@
+<!DOCTYPE html>
+<html lang="en">
+	<head>
+		<title>three.js webgpu - height fog</title>
+		<meta charset="utf-8">
+		<meta name="viewport" content="width=device-width, user-scalable=no, minimum-scale=1.0, maximum-scale=1.0">
+		<link type="text/css" rel="stylesheet" href="example.css">
+	</head>
+	<body>
+
+		<div id="info" class="invert">
+			<a href="https://threejs.org/" target="_blank" rel="noopener" class="logo-link"></a>
+
+			<div class="title-wrapper">
+				<a href="https://threejs.org/" target="_blank" rel="noopener">three.js</a><span>Height Fog</span>
+			</div>
+
+			<small>
+				Exponential Height Fog with TSL.
+			</small>
+		</div>
+
+		<script type="importmap">
+			{
+				"imports": {
+					"three": "../build/three.webgpu.js",
+					"three/webgpu": "../build/three.webgpu.js",
+					"three/tsl": "../build/three.tsl.js",
+					"three/addons/": "./jsm/"
+				}
+			}
+		</script>
+
+		<script type="module">
+
+			import * as THREE from 'three/webgpu';
+			import { exponentialHeightFogFactor, uniform, fog, color } from 'three/tsl';
+
+			import { OrbitControls } from 'three/addons/controls/OrbitControls.js';
+			import { Inspector } from 'three/addons/inspector/Inspector.js';
+
+			let camera, scene, renderer;
+			let controls;
+
+			init();
+
+			function init() {
+
+				camera = new THREE.PerspectiveCamera( 45, window.innerWidth / window.innerHeight, 1, 600 );
+				camera.position.set( 20, 10, 25 );
+
+				scene = new THREE.Scene();
+
+				// height fog
+
+				const density = uniform( 0.04 );
+				const height = uniform( 2 );
+
+				const fogFactor = exponentialHeightFogFactor( density, height );
+
+				scene.fogNode = fog( color( 0xffdfc1 ), fogFactor );
+				scene.backgroundNode = color( 0xffdfc1 );
+
+				// meshes
+
+				const geometry = new THREE.BoxGeometry( 1, 25, 1 );
+				const material = new THREE.MeshPhongNodeMaterial( { color: 0xcd959a } );
+
+				const mesh = new THREE.InstancedMesh( geometry, material, 100 );
+				mesh.position.y = - 10;
+				scene.add( mesh );
+
+				const dummy = new THREE.Object3D();
+
+				let index = 0;
+
+				for ( let i = 0; i < 10; i ++ ) {
+
+					for ( let j = 0; j < 10; j ++ ) {
+
+						dummy.position.x = - 18 + ( i * 4 );
+						dummy.position.z = - 18 + ( j * 4 );
+
+						dummy.updateMatrix();
+
+						mesh.setMatrixAt( index ++, dummy.matrix );
+
+					}
+
+				}
+
+				// lights
+
+				const directionalLight = new THREE.DirectionalLight( 0xffc0cb, 2 );
+				directionalLight.position.set( - 10, 10, 10 );
+				scene.add( directionalLight );
+
+				const ambientLight = new THREE.AmbientLight( 0xcccccc );
+				scene.add( ambientLight );
+
+				// renderer
+
+				renderer = new THREE.WebGPURenderer( { antialias: true } );
+				renderer.setPixelRatio( window.devicePixelRatio );
+				renderer.setSize( window.innerWidth, window.innerHeight );
+				renderer.setAnimationLoop( animate );
+				renderer.inspector = new Inspector();
+				document.body.appendChild( renderer.domElement );
+
+				// gui
+
+				const gui = renderer.inspector.createParameters( 'Fog Settings' );
+
+				gui.add( density, 'value', 0.001, 0.1 ).step( 0.0001 ).name( 'Density' );
+				gui.add( height, 'value', - 5, 5 ).name( 'Height' );
+
+				// controls
+
+				controls = new OrbitControls( camera, renderer.domElement );
+				controls.minDistance = 7;
+				controls.maxDistance = 100;
+				controls.maxPolarAngle = Math.PI / 2;
+				controls.enableDamping = true;
+
+				window.addEventListener( 'resize', resize );
+
+			}
+
+			function resize() {
+
+				camera.aspect = window.innerWidth / window.innerHeight;
+				camera.updateProjectionMatrix();
+
+				renderer.setSize( window.innerWidth, window.innerHeight );
+
+			}
+
+			function animate() {
+
+				controls.update();
+
+				renderer.render( scene, camera );
+
+			}
+
+		</script>
+	</body>
+</html>
diff --git a/src/Three.TSL.js b/src/Three.TSL.js
@@ -177,6 +177,7 @@ export const equal = TSL.equal;
 export const equirectUV = TSL.equirectUV;
 export const exp = TSL.exp;
 export const exp2 = TSL.exp2;
+export const exponentialHeightFogFactor = TSL.exponentialHeightFogFactor;
 export const expression = TSL.expression;
 export const faceDirection = TSL.faceDirection;
 export const faceForward = TSL.faceForward;

diff --git a/src/nodes/fog/Fog.js b/src/nodes/fog/Fog.js
@@ -1,4 +1,4 @@
-import { positionView } from '../accessors/Position.js';
+import { positionView, positionWorld } from '../accessors/Position.js';
 import { smoothstep } from '../math/MathNode.js';
 import { Fn, output, vec4 } from '../tsl/TSLBase.js';
 
@@ -62,6 +62,25 @@ export const densityFogFactor = Fn( ( [ density ], builder ) => {
 
 } );
 
+/**
+ * Constructs a new height fog factor node. This fog factor requires a Y-up coordinate system.
+ *
+ * @tsl
+ * @function
+ * @param {Node} density - Defines the fog density.
+ * @param {Node} height - The height threshold in world space. Everything below this y-coordinate is affected by fog.
+ */
+export const exponentialHeightFogFactor = Fn( ( [ density, height ], builder ) => {
+
+	const viewZ = getViewZNode( builder );
+
+	const distance = height.sub( positionWorld.y ).max( 0 ).toConst();
+	const m = distance.mul( viewZ ).toConst();
+
+	return density.mul( density, m, m ).negate().exp().oneMinus();
+
+} );
+
 /**
  * This class can be used to configure a fog for the scene.
  * Nodes of this type are assigned to `Scene.fogNode`.