javascript
/
three.js
镜像来自 https://github.com/tazdij/three.js.git


			
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							<!DOCTYPE html>
<html lang="en">
<head>
	<title>three.js webgl - indexed instancing (single box), interleaved buffers, dynamic updates</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="http://threejs.org" target="_blank" rel="noopener">three.js</a> - indexed instancing (single box)<br/>interleaved buffers, dynamic updates
		<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 mat4 modelViewMatrix;
		uniform mat4 projectionMatrix;

		attribute vec3 position;
		attribute vec3 offset;
		attribute vec2 uv;
		attribute vec4 orientation;

		varying vec2 vUv;

		// http://www.geeks3d.com/20141201/how-to-rotate-a-vertex-by-a-quaternion-in-glsl/

		vec3 applyQuaternionToVector( vec4 q, vec3 v ){

			return v + 2.0 * cross( q.xyz, cross( q.xyz, v ) + q.w * v );

		}

		void main() {

			vec3 vPosition = applyQuaternionToVector( orientation, position );

			vUv = uv;

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

		}

	</script>

	<script id="fragmentShader" type="x-shader/x-fragment">
		precision highp float;

		uniform sampler2D map;

		varying vec2 vUv;

		void main() {

			gl_FragColor = texture2D(map, vUv);

		}

	</script>

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

		import Stats from './jsm/libs/stats.module.js';

		var container, stats;

		var camera, scene, renderer;
		var orientations, instanceBuffer;


		function init() {

			container = document.getElementById( 'container' );

			camera = new THREE.PerspectiveCamera( 50, window.innerWidth / window.innerHeight, 1, 1000 );

			scene = new THREE.Scene();
			scene.background = new THREE.Color( 0x101010 );

			renderer = new THREE.WebGLRenderer();

			// geometry

			var instances = 5000;

			var geometry = new THREE.InstancedBufferGeometry();

			// per mesh data x,y,z,w,u,v,s,t for 4-element alignment
			// only use x,y,z and u,v; but x, y, z, nx, ny, nz, u, v would be a good layout
			var vertexBuffer = new THREE.InterleavedBuffer( new Float32Array( [
				// Front
				- 1, 1, 1, 0, 0, 0, 0, 0,
				1, 1, 1, 0, 1, 0, 0, 0,
				- 1, - 1, 1, 0, 0, 1, 0, 0,
				1, - 1, 1, 0, 1, 1, 0, 0,
				// Back
				1, 1, - 1, 0, 1, 0, 0, 0,
				- 1, 1, - 1, 0, 0, 0, 0, 0,
				1, - 1, - 1, 0, 1, 1, 0, 0,
				- 1, - 1, - 1, 0, 0, 1, 0, 0,
				// Left
				- 1, 1, - 1, 0, 1, 1, 0, 0,
				- 1, 1, 1, 0, 1, 0, 0, 0,
				- 1, - 1, - 1, 0, 0, 1, 0, 0,
				- 1, - 1, 1, 0, 0, 0, 0, 0,
				// Right
				1, 1, 1, 0, 1, 0, 0, 0,
				1, 1, - 1, 0, 1, 1, 0, 0,
				1, - 1, 1, 0, 0, 0, 0, 0,
				1, - 1, - 1, 0, 0, 1, 0, 0,
				// Top
				- 1, 1, 1, 0, 0, 0, 0, 0,
				1, 1, 1, 0, 1, 0, 0, 0,
				- 1, 1, - 1, 0, 0, 1, 0, 0,
				1, 1, - 1, 0, 1, 1, 0, 0,
				// Bottom
				1, - 1, 1, 0, 1, 0, 0, 0,
				- 1, - 1, 1, 0, 0, 0, 0, 0,
				1, - 1, - 1, 0, 1, 1, 0, 0,
				- 1, - 1, - 1, 0, 0, 1, 0, 0
			] ), 8 );

			// Use vertexBuffer, starting at offset 0, 3 items in position attribute
			var positions = new THREE.InterleavedBufferAttribute( vertexBuffer, 3, 0 );
			geometry.setAttribute( 'position', positions );
			// Use vertexBuffer, starting at offset 4, 2 items in uv attribute
			var uvs = new THREE.InterleavedBufferAttribute( vertexBuffer, 2, 4 );
			geometry.setAttribute( 'uv', uvs );

			var indices = new Uint16Array( [
				0, 1, 2,
				2, 1, 3,
				4, 5, 6,
				6, 5, 7,
				8, 9, 10,
				10, 9, 11,
				12, 13, 14,
				14, 13, 15,
				16, 17, 18,
				18, 17, 19,
				20, 21, 22,
				22, 21, 23
			] );

			geometry.setIndex( new THREE.BufferAttribute( indices, 1 ) );

			// per instance data
			instanceBuffer = new THREE.InstancedInterleavedBuffer( new Float32Array( instances * 8 ), 8, 1 ).setUsage( THREE.DynamicDrawUsage );
			var offsets = new THREE.InterleavedBufferAttribute( instanceBuffer, 3, 0 );

			var vector = new THREE.Vector4();
			for ( var i = 0, ul = offsets.count; i < ul; i ++ ) {

				var x = Math.random() * 100 - 50;
				var y = Math.random() * 100 - 50;
				var z = Math.random() * 100 - 50;
				vector.set( x, y, z, 0 ).normalize();
				// move out at least 5 units from center in current direction
				offsets.setXYZ( i, x + vector.x * 5, y + vector.y * 5, z + vector.z * 5 );

			}

			geometry.setAttribute( 'offset', offsets ); // per mesh translation

			orientations = new THREE.InterleavedBufferAttribute( instanceBuffer, 4, 4 );

			for ( var i = 0, ul = orientations.count; i < ul; i ++ ) {

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

				orientations.setXYZW( i, vector.x, vector.y, vector.z, vector.w );

			}

			geometry.setAttribute( 'orientation', orientations ); // per mesh orientation

			// material
			var texture = new THREE.TextureLoader().load( 'textures/crate.gif' );
			texture.anisotropy = renderer.capabilities.getMaxAnisotropy();

			var material = new THREE.RawShaderMaterial( {

				uniforms: {
					map: { value: texture }
				},
				vertexShader: document.getElementById( 'vertexShader' ).textContent,
				fragmentShader: document.getElementById( 'fragmentShader' ).textContent,
				side: THREE.DoubleSide,
				transparent: false

			} );

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


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

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

			}

			renderer.setPixelRatio( window.devicePixelRatio );
			renderer.setSize( window.innerWidth, window.innerHeight );
			container.appendChild( renderer.domElement );

			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();

		}

		var lastTime = 0;

		var moveQ = ( new THREE.Quaternion( .5, .5, .5, 0.0 ) ).normalize();
		var tmpQ = new THREE.Quaternion();
		var currentQ = new THREE.Quaternion();
		function render() {

			var time = performance.now();


			var object = scene.children[ 0 ];

			object.rotation.y = time * 0.00005;

			renderer.render( scene, camera );

			var delta = ( time - lastTime ) / 5000;
			tmpQ.set( moveQ.x * delta, moveQ.y * delta, moveQ.z * delta, 1 ).normalize();

			for ( var i = 0, ul = orientations.count; i < ul; i ++ ) {

				var index = i * instanceBuffer.stride + orientations.offset;
				currentQ.set( instanceBuffer.array[ index ], instanceBuffer.array[ index + 1 ], instanceBuffer.array[ index + 2 ], instanceBuffer.array[ index + 3 ] );
				currentQ.multiply( tmpQ );

				orientations.setXYZW( i, currentQ.x, currentQ.y, currentQ.z, currentQ.w );

			}
			instanceBuffer.needsUpdate = true;
			lastTime = time;

		}

		init();
		animate();

	</script>

</body>

</html>