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ThreeJS: Performance Tips

How to increase and not to increase the performance of your THREE.js application.

Do as little processing as possible in the animation loop. This will help to increase the frames per second performance dramatically. For example, instead of checking the scroll position to position objects in the animation loop, do it all during the scroll event.

Reuse mesh materials whenever possible. In the following example, the choice is given to reuse materials or to create materials for every new 3D object. Notice that reusing the mesh material results in a higher frames-per-second performance.


<!DOCTYPE html>
<html lang="en">
<head>
	<meta charset="UTF-8">
	<meta http-equiv="X-UA-Compatible" content="IE=edge">
	<meta name="viewport" content="width=device-width, initial-scale=1.0">
	<title>Performance</title>
	<style>
		canvas {
			position: fixed;
			top: 0;
			left: 0;
			display: block;
			width: 100%;
			height: 100vh;
		}
		#fps {
			position: fixed;
			top: 0;
			left: 0;
			background-color: rgba(0,0,0,0.5);
			color: white;
			padding: 5px;
		}
	</style>
</head>
<body>
	<canvas></canvas>
	<div id="fps">0 FPS</div>
	<script src="/js/three.min.js"></script>
	<script type="text/javascript">

(function () {

	var createCubeGridReuse = function (gridSize, cubeSize, gap) {
		var x = 0, y = 0, z = 0, rows, cols, colors = [
			new THREE.MeshPhongMaterial({ color: 0x666666 }),
			new THREE.MeshPhongMaterial({ color: 0x999999 }),
			new THREE.MeshPhongMaterial({ color: 0xCCCCCC })
		], group = new THREE.Group();
		gap = Math.abs(gap);
		gridSize = Math.pow(gridSize, 1 / 3);
		if (gridSize % 1 != 0) {
			gridSize = Math.round(gridSize);
		}
		rows = cols = gridSize;
		for (var row = 0; row < rows; row++) {
			for (var col = 0; col < cols; col++) {
				for (var depth = 0; depth < rows; depth++) {
					var position = cubeSize / 2 * rows / 2 + gap;
					x = position * row;
					y = position * col;
					z = position * depth;
					var num = (row + col + depth) % 3;
					var mesh = new THREE.Mesh(new THREE.BoxGeometry(cubeSize, cubeSize, cubeSize), colors[num]);
					mesh.receiveShadow = mesh.castShadow = true;
					mesh.position.set(x, y, z);
					group.add(mesh);
				}
			}
		}
		group.position.set(x / -2, y / -2, z / -2);
		var grid = new THREE.Group();
		grid.add(group);
		return grid;
	};

	var createCubeGrid = function (gridSize, cubeSize, gap) {
		var x = 0, y = 0, z = 0, rows, cols, colors = [0x666666, 0x999999, 0xCCCCCC], group = new THREE.Group();
		gap = Math.abs(gap);
		gridSize = Math.pow(gridSize, 1 / 3);
		if (gridSize % 1 != 0) {
			gridSize = Math.round(gridSize);
		}
		rows = cols = gridSize;
		console.log(Math.pow(gridSize, 3) + " cubes");
		for (var row = 0; row < rows; row++) {
			for (var col = 0; col < cols; col++) {
				for (var depth = 0; depth < rows; depth++) {
					var position = cubeSize / 2 * rows / 2 + gap;
					x = position * row;
					y = position * col;
					z = position * depth;
					var num = (row + col + depth) % 3;
					var mesh = new THREE.Mesh(new THREE.BoxGeometry(cubeSize, cubeSize, cubeSize), new THREE.MeshPhongMaterial({ color: colors[num] }));
					mesh.receiveShadow = mesh.castShadow = true;
					mesh.position.set(x, y, z);
					group.add(mesh);
				}
			}
		}
		group.position.set(x / -2, y / -2, z / -2);
		var grid = new THREE.Group();
		grid.add(group);
		return grid;
	};

	var canvas = document.getElementsByTagName("canvas")[0];

	// NOTE: create the scene to place objects in
	var scene = new THREE.Scene();
	scene.background = new THREE.Color(0x6699CC);
	scene.matrixWorldAutoUpdate = true;

	// NOTE: the width and height of the canvas
	var size = {
		width: canvas.offsetWidth,
		height: canvas.offsetHeight
	};


	var cameraNear = 1, cameraFar = 500;
	var camera = new THREE.PerspectiveCamera(75, size.width / size.height, cameraNear, cameraFar);

	// NOTE: position the camera in space a bit
	camera.position.z = 30;


	var renderer = new THREE.WebGLRenderer({
		canvas: canvas,
		antialias: true
	});
	renderer.shadowMap.enabled = true; // NOTE: must enable shadows on the renderer
	renderer.setPixelRatio(window.devicePixelRatio);
	renderer.setSize(size.width, size.height);
	renderer.render(scene, camera);


	var light = new THREE.DirectionalLight(0xffffff, 1.5);
	light.position.set(2, 2, 2);
	light.castShadow = true;
	light.shadow.mapSize.width = 1024;
	light.shadow.mapSize.height = 1024;
	light.shadow.camera.near = cameraNear;
	light.shadow.camera.far = cameraFar;
	scene.add(light);
	scene.add(new THREE.AmbientLight(0xffffff, .3));

	var reuse = confirm("Okay to be efficient and reuse mesh materials for a greater frames-per-second performance?");
	var num = parseInt(prompt("Enter grid size:", 21) || 21) || 21;
	var size = num*num*num;
	if(!confirm("This will create " + size + " cubes.")) { alert("Aborting!"); return; }
	
	var grid = reuse ? createCubeGridReuse(size, 0.2, 0.001) : createCubeGrid(size, 0.2, 0.001);
	scene.add(grid);

	var frame = Math.PI / 192;

	var frameCount = 0;

	var getFrameCount = function () {
		document.getElementById("fps").innerText = frameCount + " FPS, reuse: " + (reuse ? "yes" : "no");
		frameCount = 0;
	};

	setInterval(getFrameCount, 1000);

	// NOTE: MUST HAVE AN ANIMATE FUNCTION
	var animate = function () {

		frameCount++;

		grid.rotation.x += frame;
		grid.rotation.y += frame;
		
		renderer.render(scene, camera);
		requestAnimationFrame(animate);
	};
	animate();

})();

	</script>
</body>
</html>

Setting the antialias property of the renderer to false will increase the performance but at the cost of image quality, even on high resolution monitors.

Instead of adding and removing lights from a scene set their intensity to low values. This is because the renderer must recompile the shader program. The THREE.DirectionalLight is a good lightweight light to use.

Set the camera frustum to be as little as possible to support the scene.

Using models, like glTF ones, just slows things down, particularly for complex 3D models. Sometimes they are required but they do not always play nice in the world of THREE.js. Shadows can create problems, for example.

The penalty to using the highest quality mesh THREE.MeshStandardMaterial is negligible. The performance difference between this and THREE.MeshBasicMaterial is about 10% (if that), so using a lesser mesh material like THREE.MeshPhongMaterial is really only required for the largest projects or for adapting to lesser hardware. It is a popular myth that the higher quality materials come with a big performance penalty, but the THREE developers have probably made some performance increases (through caching) that make the penalty less now than when this myth was originally floated.

In order of lowest to highest performance:

  1. THREE.MeshStandardMaterial
  2. THREE.MeshPhongMaterial
  3. THREE.MeshLambertMaterial
  4. THREE.MeshBasicMaterial

Bear in mind that changing properties of the mesh material will affect performance.

This example compares both THREE.MeshStandardMaterial (the highest image quality) and THREE.MeshBasicMaterial (the lowest):


<!DOCTYPE html>
<html lang="en">
<head>
	<meta charset="UTF-8">
	<meta http-equiv="X-UA-Compatible" content="IE=edge">
	<meta name="viewport" content="width=device-width, initial-scale=1.0">
	<title>Performance</title>
	<style>
		canvas {
			position: fixed;
			top: 0;
			left: 0;
			display: block;
			width: 100%;
			height: 100vh;
		}
		#fps {
			position: fixed;
			top: 0;
			left: 0;
			background-color: rgba(0,0,0,0.5);
			color: white;
			padding: 5px;
		}
	</style>
</head>
<body>
	<canvas></canvas>
	<div id="fps">0 FPS</div>
	<script src="/js/three.min.js"></script>
	<script type="text/javascript">

(function () {

	var createCubeGridHi = function (gridSize, cubeSize, gap) {
		var x = 0, y = 0, z = 0, rows, cols, colors = [
			new THREE.MeshStandardMaterial({ color: 0x666666, roughness: 0.5, metalness: 0.5 }),
			new THREE.MeshStandardMaterial({ color: 0x999999, roughness: 0.5, metalness: 0.5 }),
			new THREE.MeshStandardMaterial({ color: 0xCCCCCC, roughness: 0.5, metalness: 0.5 })
		], group = new THREE.Group();
		gap = Math.abs(gap);
		gridSize = Math.pow(gridSize, 1 / 3);
		if (gridSize % 1 != 0) {
			gridSize = Math.round(gridSize);
		}
		rows = cols = gridSize;
		for (var row = 0; row < rows; row++) {
			for (var col = 0; col < cols; col++) {
				for (var depth = 0; depth < rows; depth++) {
					var position = cubeSize / 2 * rows / 2 + gap;
					x = position * row;
					y = position * col;
					z = position * depth;
					var num = (row + col + depth) % 3;
					var mesh = new THREE.Mesh(new THREE.BoxGeometry(cubeSize, cubeSize, cubeSize), colors[num]);
					mesh.receiveShadow = mesh.castShadow = true;
					mesh.position.set(x, y, z);
					group.add(mesh);
				}
			}
		}
		group.position.set(x / -2, y / -2, z / -2);
		var grid = new THREE.Group();
		grid.add(group);
		return grid;
	};

	var createCubeGridLo = function (gridSize, cubeSize, gap) {
		var x = 0, y = 0, z = 0, rows, cols, colors = [
			new THREE.MeshBasicMaterial({ color: 0x666666 }),
			new THREE.MeshBasicMaterial({ color: 0x999999 }),
			new THREE.MeshBasicMaterial({ color: 0xCCCCCC })
		], group = new THREE.Group();
		gap = Math.abs(gap);
		gridSize = Math.pow(gridSize, 1 / 3);
		if (gridSize % 1 != 0) {
			gridSize = Math.round(gridSize);
		}
		rows = cols = gridSize;
		for (var row = 0; row < rows; row++) {
			for (var col = 0; col < cols; col++) {
				for (var depth = 0; depth < rows; depth++) {
					var position = cubeSize / 2 * rows / 2 + gap;
					x = position * row;
					y = position * col;
					z = position * depth;
					var num = (row + col + depth) % 3;
					var mesh = new THREE.Mesh(new THREE.BoxGeometry(cubeSize, cubeSize, cubeSize), colors[num]);
					mesh.receiveShadow = mesh.castShadow = true;
					mesh.position.set(x, y, z);
					group.add(mesh);
				}
			}
		}
		group.position.set(x / -2, y / -2, z / -2);
		var grid = new THREE.Group();
		grid.add(group);
		return grid;
	};

	var canvas = document.getElementsByTagName("canvas")[0];

	// NOTE: create the scene to place objects in
	var scene = new THREE.Scene();
	scene.background = new THREE.Color(0x6699CC);
	scene.matrixWorldAutoUpdate = true;

	// NOTE: the width and height of the canvas
	var size = {
		width: canvas.offsetWidth,
		height: canvas.offsetHeight
	};


	var cameraNear = 1, cameraFar = 500;
	var camera = new THREE.PerspectiveCamera(75, size.width / size.height, cameraNear, cameraFar);

	// NOTE: position the camera in space a bit
	camera.position.z = 70;


	var renderer = new THREE.WebGLRenderer({
		canvas: canvas,
		antialias: true
	});
	renderer.shadowMap.enabled = true; // NOTE: must enable shadows on the renderer
	renderer.setPixelRatio(window.devicePixelRatio);
	renderer.setSize(size.width, size.height);
	renderer.render(scene, camera);


	var light = new THREE.DirectionalLight(0xffffff, 1.5);
	light.position.set(2, 2, 2);
	light.castShadow = true;
	light.shadow.mapSize.width = 1024;
	light.shadow.mapSize.height = 1024;
	light.shadow.camera.near = cameraNear;
	light.shadow.camera.far = cameraFar;
	scene.add(light);
	scene.add(new THREE.AmbientLight(0xffffff, .3));

	var hi = confirm("Okay to use highest quality mesh materials?");
	var num = parseInt(prompt("Enter grid size:", 25) || 25) || 25;
	var size = num*num*num;
	if(!confirm("This will create " + size + " cubes.")) { alert("Aborting!"); return; }
	
	var grid = hi ? createCubeGridHi(size, 0.5, 0.0001) : createCubeGridLo(size, 0.5, 0.0001);
	scene.add(grid);

	var frame = Math.PI / 192;

	var frameCount = 0;

	var getFrameCount = function () {
		document.getElementById("fps").innerText = frameCount + " FPS, hi: " + (hi ? "yes" : "no");
		frameCount = 0;
	};

	setInterval(getFrameCount, 1000);

	// NOTE: MUST HAVE AN ANIMATE FUNCTION
	var animate = function () {

		frameCount++;

		grid.rotation.x += frame;
		grid.rotation.y += frame;
		
		renderer.render(scene, camera);
		requestAnimationFrame(animate);
	};
	animate();

})();

	</script>
</body>
</html>
ThreeJS: A Survival Guide

A tutorial on the basics of THREE.js and a guide to more advanced features including examples, information about mesh materials both reflective and not, lighting, groups, textures and how to load them, displacement and alpha maps, and how to modify a scene during the window scroll event.
ThreeJS: Bouncing Ball

Two ways to create a bouncing ball using THREE.js; use sine/cosine or basic physics to bounce a ball.
ThreeJS: Cast Shadows

Cast object shadows and receive shadows from objects; how to create shadows in THREE.js, including how to configure a 3D model to cast and receive a shadow.
ThreeJS: Cover Background with Image without Stretching

How to set the background image to cover the scene without stretching it; how to make the background responsive for mobile apps using THREE.js.
ThreeJS: Create a Cube Array

How to create a cube grid array using THREE.js.
ThreeJS: Create an Egg

How to create a 3D egg object/geometry/mesh using the THREE.js LatheGeometry.
ThreeJS: Create Transparency with PNG Images

How to create transparency using Portable Network Graphics (PNG) images in THREE.js.
ThreeJS: How to Orbit a Body

How to make a 3D/mesh object (the satellite) orbit another object (the body) using THREE.js; how to make a celestial/solar system.
ThreeJS: Make an Object Appear to Follow the Mouse Cursor

How to make a mesh object appear to follow the mouse cursor by moving the camera in THREE.js.
ThreeJS: Make Objects Appear to Watch the Mouse Cursor or Touch Point

How to make mesh objects appear to watch the moving mouse cursor or point of touch on mobile devices in THREE.js.
ThreeJS: Move Camera Z-position Based on Object Size to Make a Responsive App

How to move the camera distance, or z-position, to fit an object within the size of the canvas or screen; how make an object fit within the confines of the canvas regardless of aspect ratio; how to make a mobile responsive web application using THREE.js.
ThreeJS: Performance Tips

How to increase and not to increase the performance of your THREE.js application.
ThreeJS: Raytracer Example

How to access individual objects on the canvas used by THREE.js.
ThreeJS: Transition from One Color to Another

How to gradually transition from one color to another using THREE.js with examples changing the scene background during the scroll event and animation event.
ThreeJS: Transparent Background

How to make the THREE.js canvas background transparent so that the HTML/CSS behind it can be seen.
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