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


			
							123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271272273274275276277278279280281282283284285286287288289290291292293
							<!DOCTYPE html>
<html lang="en">
	<head>
		<title>three.js webgl - buffergeometry - lines drawrange</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;
			}
		</style>
	</head>
	<body>

		<div id="container"></div>
		<div id="info">
			<a href="https://threejs.org" target="_blank" rel="noopener">three.js</a> webgl - buffergeometry drawrange<br/>
			by <a href="https://twitter.com/fernandojsg">fernandojsg</a>
		</div>

		<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';

			import { OrbitControls } from './jsm/controls/OrbitControls.js';

			var group;
			var container, stats;
			var particlesData = [];
			var camera, scene, renderer;
			var positions, colors;
			var particles;
			var pointCloud;
			var particlePositions;
			var linesMesh;

			var maxParticleCount = 1000;
			var particleCount = 500;
			var r = 800;
			var rHalf = r / 2;

			var effectController = {
				showDots: true,
				showLines: true,
				minDistance: 150,
				limitConnections: false,
				maxConnections: 20,
				particleCount: 500
			};

			init();
			animate();

			function initGUI() {

				var gui = new GUI();

				gui.add( effectController, "showDots" ).onChange( function ( value ) {

					pointCloud.visible = value;

				} );
				gui.add( effectController, "showLines" ).onChange( function ( value ) {

					linesMesh.visible = value;

				} );
				gui.add( effectController, "minDistance", 10, 300 );
				gui.add( effectController, "limitConnections" );
				gui.add( effectController, "maxConnections", 0, 30, 1 );
				gui.add( effectController, "particleCount", 0, maxParticleCount, 1 ).onChange( function ( value ) {

					particleCount = parseInt( value );
					particles.setDrawRange( 0, particleCount );

				} );

			}

			function init() {

				initGUI();

				container = document.getElementById( 'container' );

				camera = new THREE.PerspectiveCamera( 45, window.innerWidth / window.innerHeight, 1, 4000 );
				camera.position.z = 1750;

				var controls = new OrbitControls( camera, container );
				controls.minDistance = 1000;
				controls.maxDistance = 3000;

				scene = new THREE.Scene();


				group = new THREE.Group();
				scene.add( group );

				var helper = new THREE.BoxHelper( new THREE.Mesh( new THREE.BoxBufferGeometry( r, r, r ) ) );
				helper.material.color.setHex( 0x101010 );
				helper.material.blending = THREE.AdditiveBlending;
				helper.material.transparent = true;
				group.add( helper );

				var segments = maxParticleCount * maxParticleCount;

				positions = new Float32Array( segments * 3 );
				colors = new Float32Array( segments * 3 );

				var pMaterial = new THREE.PointsMaterial( {
					color: 0xFFFFFF,
					size: 3,
					blending: THREE.AdditiveBlending,
					transparent: true,
					sizeAttenuation: false
				} );

				particles = new THREE.BufferGeometry();
				particlePositions = new Float32Array( maxParticleCount * 3 );

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

					var x = Math.random() * r - r / 2;
					var y = Math.random() * r - r / 2;
					var z = Math.random() * r - r / 2;

					particlePositions[ i * 3 ] = x;
					particlePositions[ i * 3 + 1 ] = y;
					particlePositions[ i * 3 + 2 ] = z;

					// add it to the geometry
					particlesData.push( {
						velocity: new THREE.Vector3( - 1 + Math.random() * 2, - 1 + Math.random() * 2, - 1 + Math.random() * 2 ),
						numConnections: 0
					} );

				}

				particles.setDrawRange( 0, particleCount );
				particles.setAttribute( 'position', new THREE.BufferAttribute( particlePositions, 3 ).setUsage( THREE.DynamicDrawUsage ) );

				// create the particle system
				pointCloud = new THREE.Points( particles, pMaterial );
				group.add( pointCloud );

				var geometry = new THREE.BufferGeometry();

				geometry.setAttribute( 'position', new THREE.BufferAttribute( positions, 3 ).setUsage( THREE.DynamicDrawUsage ) );
				geometry.setAttribute( 'color', new THREE.BufferAttribute( colors, 3 ).setUsage( THREE.DynamicDrawUsage ) );

				geometry.computeBoundingSphere();

				geometry.setDrawRange( 0, 0 );

				var material = new THREE.LineBasicMaterial( {
					vertexColors: true,
					blending: THREE.AdditiveBlending,
					transparent: true
				} );

				linesMesh = new THREE.LineSegments( geometry, material );
				group.add( linesMesh );

				//

				renderer = new THREE.WebGLRenderer( { antialias: true } );
				renderer.setPixelRatio( window.devicePixelRatio );
				renderer.setSize( window.innerWidth, window.innerHeight );
				renderer.outputEncoding = THREE.sRGBEncoding;

				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() {

				var vertexpos = 0;
				var colorpos = 0;
				var numConnected = 0;

				for ( var i = 0; i < particleCount; i ++ )
					particlesData[ i ].numConnections = 0;

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

					// get the particle
					var particleData = particlesData[ i ];

					particlePositions[ i * 3 ] += particleData.velocity.x;
					particlePositions[ i * 3 + 1 ] += particleData.velocity.y;
					particlePositions[ i * 3 + 2 ] += particleData.velocity.z;

					if ( particlePositions[ i * 3 + 1 ] < - rHalf || particlePositions[ i * 3 + 1 ] > rHalf )
						particleData.velocity.y = - particleData.velocity.y;

					if ( particlePositions[ i * 3 ] < - rHalf || particlePositions[ i * 3 ] > rHalf )
						particleData.velocity.x = - particleData.velocity.x;

					if ( particlePositions[ i * 3 + 2 ] < - rHalf || particlePositions[ i * 3 + 2 ] > rHalf )
						particleData.velocity.z = - particleData.velocity.z;

					if ( effectController.limitConnections && particleData.numConnections >= effectController.maxConnections )
						continue;

					// Check collision
					for ( var j = i + 1; j < particleCount; j ++ ) {

						var particleDataB = particlesData[ j ];
						if ( effectController.limitConnections && particleDataB.numConnections >= effectController.maxConnections )
							continue;

						var dx = particlePositions[ i * 3 ] - particlePositions[ j * 3 ];
						var dy = particlePositions[ i * 3 + 1 ] - particlePositions[ j * 3 + 1 ];
						var dz = particlePositions[ i * 3 + 2 ] - particlePositions[ j * 3 + 2 ];
						var dist = Math.sqrt( dx * dx + dy * dy + dz * dz );

						if ( dist < effectController.minDistance ) {

							particleData.numConnections ++;
							particleDataB.numConnections ++;

							var alpha = 1.0 - dist / effectController.minDistance;

							positions[ vertexpos ++ ] = particlePositions[ i * 3 ];
							positions[ vertexpos ++ ] = particlePositions[ i * 3 + 1 ];
							positions[ vertexpos ++ ] = particlePositions[ i * 3 + 2 ];

							positions[ vertexpos ++ ] = particlePositions[ j * 3 ];
							positions[ vertexpos ++ ] = particlePositions[ j * 3 + 1 ];
							positions[ vertexpos ++ ] = particlePositions[ j * 3 + 2 ];

							colors[ colorpos ++ ] = alpha;
							colors[ colorpos ++ ] = alpha;
							colors[ colorpos ++ ] = alpha;

							colors[ colorpos ++ ] = alpha;
							colors[ colorpos ++ ] = alpha;
							colors[ colorpos ++ ] = alpha;

							numConnected ++;

						}

					}

				}


				linesMesh.geometry.setDrawRange( 0, numConnected * 2 );
				linesMesh.geometry.attributes.position.needsUpdate = true;
				linesMesh.geometry.attributes.color.needsUpdate = true;

				pointCloud.geometry.attributes.position.needsUpdate = true;

				requestAnimationFrame( animate );

				stats.update();
				render();

			}

			function render() {

				var time = Date.now() * 0.001;

				group.rotation.y = time * 0.1;
				renderer.render( scene, camera );

			}

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