examples/webgl_buffergeometry_instancing2.html

<!DOCTYPE html>
<html lang="en">
<head>
	<title>three.js webgl - instancing test (meshes)</title>
	<meta charset="utf-8">
	<meta name="viewport" content="width=device-width, user-scalable=no, minimum-scale=1.0, maximum-scale=1.0">
	<style>
		body {
			color: #ffffff;
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			font-size: 13px;
			text-align: center;
			font-weight: bold;
			background-color: #000000;
			margin: 0px;
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		#info {
			position: absolute;
			top: 0px;
			width: 100%;
			padding: 5px;
		}

		a {
			color: #ffffff;
		}

		#notSupported {
			width: 50%;
			margin: auto;
			border: 2px red solid;
			margin-top: 20px;
			padding: 10px;
		}
	</style>
</head>
<body>

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

	<script src="../build/three.js"></script>
	<script src="js/WebGL.js"></script>
	<script src="js/libs/stats.min.js"></script>

	<script src="js/controls/TrackballControls.js"></script>

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

		attribute vec3 instancePosition;
		attribute vec4 instanceQuaternion;
		attribute vec3 instanceScale;

		varying vec3 vColor;

		vec3 applyTRS( vec3 position, vec3 translation, vec4 quaternion, vec3 scale ) {

			position *= scale;
			position += 2.0 * cross( quaternion.xyz, cross( quaternion.xyz, position ) + quaternion.w * position );
			return position + translation;

		}

		void main(){

			vColor = color;

			vec3 transformed = applyTRS( position.xyz, instancePosition, instanceQuaternion, instanceScale );

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

		}

	</script>

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

		precision highp float;
		varying vec3 vColor;

		void main() {

			gl_FragColor = vec4( vColor, 1.0 );

		}

	</script>

	<script>

		if ( WEBGL.isWebGLAvailable() === false ) {

			document.body.appendChild( WEBGL.getWebGLErrorMessage() );

		}

		var container, stats;

		var camera, scene, renderer;

		var controls;

		init();
		animate();

		function init() {

			container = document.getElementById( 'container' );

			camera = new THREE.PerspectiveCamera( 50, window.innerWidth / window.innerHeight, 0.01, 100 );
			camera.position.z = 4;

			controls = new THREE.TrackballControls( camera );

			scene = new THREE.Scene();

			//

			var geometry = new THREE.IcosahedronBufferGeometry( 0.1, 1 );

			var colors = [];

			for ( var i = 0, l = geometry.attributes.position.count; i < l; i ++ ) {

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

			}

			geometry.addAttribute( 'color', new THREE.Float32BufferAttribute( colors, 3 ) );

			var material = new THREE.MeshBasicMaterial( { color: 0xff0000, vertexColors: THREE.VertexColors } );

			//

			var instances = 100;

			var instancePositions = [];
			var instanceQuaternions = [];
			var instanceScales = [];

			// we create for each mesh a counterpart in our instanced geometry data

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

				// the red meshes are drawn with separate draw calls

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

				var position = mesh.position;
				var quaternion = mesh.quaternion;
				var scale = mesh.scale;

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

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

				scale.set( Math.random() * 2, Math.random() * 2, Math.random() * 2 );

				// instanced attribute data

				instancePositions.push( position.x, position.y, position.z );
				instanceQuaternions.push( quaternion.x, quaternion.y, quaternion.z, quaternion.w );
				instanceScales.push( scale.x, scale.y, scale.z );

			}

			var instancedGeometry = new THREE.InstancedBufferGeometry();
			instancedGeometry.attributes.position = geometry.attributes.position;
			instancedGeometry.attributes.color = geometry.attributes.color;

			instancedGeometry.addAttribute( 'instancePosition', new THREE.InstancedBufferAttribute( new Float32Array( instancePositions ), 3 ) );
			instancedGeometry.addAttribute( 'instanceQuaternion', new THREE.InstancedBufferAttribute( new Float32Array( instanceQuaternions ), 4 ) );
			instancedGeometry.addAttribute( 'instanceScale', new THREE.InstancedBufferAttribute( new Float32Array( instanceScales ), 3 ) );

			//

			var shaderMaterial = new THREE.ShaderMaterial( {

				uniforms: {},
				vertexShader: document.getElementById( 'vertexShader' ).textContent,
				fragmentShader: document.getElementById( 'fragmentShader' ).textContent,
				vertexColors: true

			} );

			// counterparts are drawn all at once with a single draw call (via instanced rendering)

			var instancedMesh = new THREE.Mesh( instancedGeometry, shaderMaterial );
			instancedMesh.position.x = 0.1;
			scene.add( instancedMesh );

			//

			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;

			}

			//

			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() {

			controls.update();

			renderer.render( scene, camera );

		}

	</script>

</body>

</html>