examples/webgl_buffergeometry_instancing.html

<!DOCTYPE html>
<html lang="en">
<head>
	<title>three.js webgl - instancing test (single triangle)</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="main.css">
	<style>
		a {
			color: #08f;
		}
		#notSupported {
			width: 50%;
			margin: auto;
			background-color: #f00;
			margin-top: 20px;
			padding: 10px;
		}
	</style>
</head>
<body>

	<div id="container"></div>
	<div id="info">
		<a href="https://threejs.org" target="_blank" rel="noopener">three.js</a> - instancing demo (single triangle)
		<div id="notSupported" style="display:none">Sorry your graphics card + browser does not support hardware instancing</div>
	</div>

	<script id="vertexShader" type="x-shader/x-vertex">
		precision highp float;

		uniform float sineTime;

		uniform mat4 modelViewMatrix;
		uniform mat4 projectionMatrix;

		attribute vec3 position;
		attribute vec3 offset;
		attribute vec4 color;
		attribute vec4 orientationStart;
		attribute vec4 orientationEnd;

		varying vec3 vPosition;
		varying vec4 vColor;

		void main(){

			vPosition = offset * max( abs( sineTime * 2.0 + 1.0 ), 0.5 ) + position;
			vec4 orientation = normalize( mix( orientationStart, orientationEnd, sineTime ) );
			vec3 vcV = cross( orientation.xyz, vPosition );
			vPosition = vcV * ( 2.0 * orientation.w ) + ( cross( orientation.xyz, vcV ) * 2.0 + vPosition );

			vColor = color;

			gl_Position = projectionMatrix * modelViewMatrix * vec4( vPosition, 1.0 );

		}

	</script>

	<script id="fragmentShader" type="x-shader/x-fragment">

		precision highp float;

		uniform float time;

		varying vec3 vPosition;
		varying vec4 vColor;

		void main() {

			vec4 color = vec4( vColor );
			color.r += sin( vPosition.x * 10.0 + time ) * 0.5;

			gl_FragColor = color;

		}

	</script>

	<script type="module">
		import * as THREE from '../build/three.module.js';

		import Stats from './jsm/libs/stats.module.js';
		import { GUI } from './jsm/libs/dat.gui.module.js';

		var container, stats;

		var camera, scene, renderer;

		init();
		animate();

		function init() {

			container = document.getElementById( 'container' );

			camera = new THREE.PerspectiveCamera( 50, window.innerWidth / window.innerHeight, 1, 10 );
			camera.position.z = 2;

			scene = new THREE.Scene();

			// geometry

			var vector = new THREE.Vector4();

			var instances = 50000;

			var positions = [];
			var offsets = [];
			var colors = [];
			var orientationsStart = [];
			var orientationsEnd = [];

			positions.push( 0.025, - 0.025, 0 );
			positions.push( - 0.025, 0.025, 0 );
			positions.push( 0, 0, 0.025 );

			// instanced attributes

			for ( var i = 0; i < instances; i ++ ) {

				// offsets

				offsets.push( Math.random() - 0.5, Math.random() - 0.5, Math.random() - 0.5 );

				// colors

				colors.push( Math.random(), Math.random(), Math.random(), Math.random() );

				// orientation start

				vector.set( Math.random() * 2 - 1, Math.random() * 2 - 1, Math.random() * 2 - 1, Math.random() * 2 - 1 );
				vector.normalize();

				orientationsStart.push( vector.x, vector.y, vector.z, vector.w );

				// orientation end

				vector.set( Math.random() * 2 - 1, Math.random() * 2 - 1, Math.random() * 2 - 1, Math.random() * 2 - 1 );
				vector.normalize();

				orientationsEnd.push( vector.x, vector.y, vector.z, vector.w );

			}

			var geometry = new THREE.InstancedBufferGeometry();
			geometry.maxInstancedCount = instances; // set so its initalized for dat.GUI, will be set in first draw otherwise

			geometry.setAttribute( 'position', new THREE.Float32BufferAttribute( positions, 3 ) );

			geometry.setAttribute( 'offset', new THREE.InstancedBufferAttribute( new Float32Array( offsets ), 3 ) );
			geometry.setAttribute( 'color', new THREE.InstancedBufferAttribute( new Float32Array( colors ), 4 ) );
			geometry.setAttribute( 'orientationStart', new THREE.InstancedBufferAttribute( new Float32Array( orientationsStart ), 4 ) );
			geometry.setAttribute( 'orientationEnd', new THREE.InstancedBufferAttribute( new Float32Array( orientationsEnd ), 4 ) );

			// material

			var material = new THREE.RawShaderMaterial( {

				uniforms: {
					"time": { value: 1.0 },
					"sineTime": { value: 1.0 }
				},
				vertexShader: document.getElementById( 'vertexShader' ).textContent,
				fragmentShader: document.getElementById( 'fragmentShader' ).textContent,
				side: THREE.DoubleSide,
				transparent: true

			} );

			//

			var mesh = new THREE.Mesh( geometry, material );
			scene.add( mesh );

			//

			renderer = new THREE.WebGLRenderer();
			renderer.setPixelRatio( window.devicePixelRatio );
			renderer.setSize( window.innerWidth, window.innerHeight );
			container.appendChild( renderer.domElement );

			if ( renderer.extensions.get( 'ANGLE_instanced_arrays' ) === null ) {

				document.getElementById( 'notSupported' ).style.display = '';
				return;

			}

			//

			var gui = new GUI( { width: 350 } );
			gui.add( geometry, 'maxInstancedCount', 0, instances );

			//

			stats = new Stats();
			container.appendChild( stats.dom );

			//

			window.addEventListener( 'resize', onWindowResize, false );

		}

		function onWindowResize() {

			camera.aspect = window.innerWidth / window.innerHeight;
			camera.updateProjectionMatrix();

			renderer.setSize( window.innerWidth, window.innerHeight );

		}

		//

		function animate() {

			requestAnimationFrame( animate );

			render();
			stats.update();

		}

		function render() {

			var time = performance.now();

			var object = scene.children[ 0 ];

			object.rotation.y = time * 0.0005;
			object.material.uniforms[ "time" ].value = time * 0.005;
			object.material.uniforms[ "sineTime" ].value = Math.sin( object.material.uniforms[ "time" ].value * 0.05 );

			renderer.render( scene, camera );

		}

	</script>

</body>

</html>