先看看官方的例子
https://threejs.org/examples/#canvas_particles_sprites
根据这个改的
首先看一下源码，了解一下
<!DOCTYPE html>
<html lang="en">
<head>
<title>three.js canvas - particles - sprites</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 {
background-color: #000000;
margin: 0px;
overflow: hidden;
}
a {
color: #0078ff;
}
</style>
</head>
<body>
<script src="../build/three.js"></script>
<script src="js/renderers/Projector.js"></script>
<script src="js/renderers/CanvasRenderer.js"></script>
<script src="js/libs/stats.min.js"></script>
<script src="js/libs/tween.min.js"></script>
<script>
var container, stats;
var camera, scene, renderer, particle;
var mouseX = 0, mouseY = 0;
var windowHalfX = window.innerWidth / 2;
var windowHalfY = window.innerHeight / 2;
init();
animate();
function init() {
container = document.createElement( 'div' );
document.body.appendChild( container );
camera = new THREE.PerspectiveCamera( 75, window.innerWidth / window.innerHeight, 1, 5000 );
camera.position.z = 1000;
scene = new THREE.Scene();
scene.background = new THREE.Color( 0x000040 );
var material = new THREE.SpriteMaterial( {
map: new THREE.CanvasTexture( generateSprite() ),
blending: THREE.AdditiveBlending
} );
for ( var i = 0; i < 1000; i++ ) {
particle = new THREE.Sprite( material );
initParticle( particle, i * 10 );
scene.add( particle );
}
renderer = new THREE.CanvasRenderer();
renderer.setPixelRatio( window.devicePixelRatio );
renderer.setSize( window.innerWidth, window.innerHeight );
container.appendChild( renderer.domElement );
stats = new Stats();
container.appendChild( stats.dom );
document.addEventListener( 'mousemove', onDocumentMouseMove, false );
document.addEventListener( 'touchstart', onDocumentTouchStart, false );
document.addEventListener( 'touchmove', onDocumentTouchMove, false );
//
window.addEventListener( 'resize', onWindowResize, false );
}
function onWindowResize() {
windowHalfX = window.innerWidth / 2;
windowHalfY = window.innerHeight / 2;
camera.aspect = window.innerWidth / window.innerHeight;
camera.updateProjectionMatrix();
renderer.setSize( window.innerWidth, window.innerHeight );
}
function generateSprite() {
var canvas = document.createElement( 'canvas' );
canvas.width = 16;
canvas.height = 16;
var context = canvas.getContext( '2d' );
var gradient = context.createRadialGradient( canvas.width / 2, canvas.height / 2, 0, canvas.width / 2, canvas.height / 2, canvas.width / 2 );
gradient.addColorStop( 0, 'rgba(255,255,255,1)' );
gradient.addColorStop( 0.2, 'rgba(0,255,255,1)' );
gradient.addColorStop( 0.4, 'rgba(0,0,64,1)' );
gradient.addColorStop( 1, 'rgba(0,0,0,1)' );
context.fillStyle = gradient;
context.fillRect( 0, 0, canvas.width, canvas.height );
return canvas;
}
function initParticle( particle, delay ) {
var particle = this instanceof THREE.Sprite ? this : particle;
var delay = delay !== undefined ? delay : 0;
particle.position.set( 0, 0, 0 );
particle.scale.x = particle.scale.y = Math.random() * 32 + 16;
new TWEEN.Tween( particle )
.delay( delay )
.to( {}, 10000 )
.onComplete( initParticle )
.start();
new TWEEN.Tween( particle.position )
.delay( delay )
.to( { x: Math.random() * 4000 - 2000, y: Math.random() * 1000 - 500, z: Math.random() * 4000 - 2000 }, 10000 )
.start();
new TWEEN.Tween( particle.scale )
.delay( delay )
.to( { x: 0.01, y: 0.01 }, 10000 )
.start();
}
//
function onDocumentMouseMove( event ) {
mouseX = event.clientX - windowHalfX;
mouseY = event.clientY - windowHalfY;
}
function onDocumentTouchStart( event ) {
if ( event.touches.length == 1 ) {
event.preventDefault();
mouseX = event.touches[ 0 ].pageX - windowHalfX;
mouseY = event.touches[ 0 ].pageY - windowHalfY;
}
}
function onDocumentTouchMove( event ) {
if ( event.touches.length == 1 ) {
event.preventDefault();
mouseX = event.touches[ 0 ].pageX - windowHalfX;
mouseY = event.touches[ 0 ].pageY - windowHalfY;
}
}
//
function animate() {
requestAnimationFrame( animate );
render();
stats.update();
}
function render() {
TWEEN.update();
camera.position.x += ( mouseX - camera.position.x ) * 0.05;
camera.position.y += ( - mouseY - camera.position.y ) * 0.05;
camera.lookAt( scene.position );
renderer.render( scene, camera );
}
</script>
</body>
</html>
上面是官方的例子
接着修改参数，得到我想要的结果
<!DOCTYPE html>
<html lang="en">
<head>
<title>three.js canvas - particles - sprites</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 {
background-color: #000000;
margin: 0px;
overflow: hidden;
}
a {
color: #0078ff;
}
</style>
</head>
<body>
<script src="../js/three.js"></script>
<script src="../js/renderers/Projector.js"></script>
<script src="../js/renderers/CanvasRenderer.js"></script>
<script src="../js/libs/stats.min.js"></script>
<script src="../js/libs/tween.min.js"></script>
<script>
//容器container,帧检测
var container, stats;
//相机，场景，渲染器，粒子
var camera, scene, renderer, particle;
//鼠标坐标
var mouseX = 0, mouseY = 0;
//窗口中心点
var windowHalfX = window.innerWidth / 2;
var windowHalfY = window.innerHeight / 2;
//初始化一个空容器，装载粒子
var krq = new THREE.Object3D();
init();
animate();
//初始化
function init() {
//创建一个div容器
container = document.createElement( 'div' );
//添加到document中
document.body.appendChild( container );
//初始化相机
camera = new THREE.PerspectiveCamera( 75, window.innerWidth / window.innerHeight, 1, 5000 );
//(0,0,1000)
camera.position.z = 1000;
//初始化场景
scene = new THREE.Scene();
//场景背景
scene.background = new THREE.Color( 0x000040 );
//sprite材质
var material = new THREE.SpriteMaterial( {
//以canvas作为纹理
map: new THREE.CanvasTexture( generateSprite() ),
//混合度 加法混合
blending: THREE.AdditiveBlending
} );
//循环1000 添加粒子
for ( var i = 0; i < 1000; i++ ) {
particle = new THREE.Sprite( material );
initParticle( particle, i * 10 );
krq.add(particle);
}
//使用canvas渲染
renderer = new THREE.CanvasRenderer();
//设置像素比
renderer.setPixelRatio( window.devicePixelRatio );
//设置大小
renderer.setSize( window.innerWidth, window.innerHeight );
//添加render到容器
container.appendChild( renderer.domElement );
//空容器设置
krq.position.z = -200;
krq.rotateZ(1);
scene.add(krq);
//帧监测
stats = new Stats();
container.appendChild( stats.dom );
//添加监听器，使之能对camera进行控制
// document.addEventListener( 'mousemove', onDocumentMouseMove, false );
//document.addEventListener( 'touchstart', onDocumentTouchStart, false );
//document.addEventListener( 'touchmove', onDocumentTouchMove, false );
//窗口大小检测
window.addEventListener( 'resize', onWindowResize, false );
}
function onWindowResize() {
windowHalfX = window.innerWidth / 2;
windowHalfY = window.innerHeight / 2;
camera.aspect = window.innerWidth / window.innerHeight;
camera.updateProjectionMatrix();
renderer.setSize( window.innerWidth, window.innerHeight );
}
/**
* 返回canvas 作为纹理
* @returns {HTMLCanvasElement}
*/
function generateSprite() {
//创建canvas并设置大小
var canvas = document.createElement( 'canvas' );
canvas.width = 16;
canvas.height = 16;
//得到2d，canvas
var context = canvas.getContext( '2d' );
//渐变方式
var gradient = context.createRadialGradient( canvas.width / 2, canvas.height / 2, 0, canvas.width / 2, canvas.height / 2, canvas.width / 2 );
/*gradient.addColorStop( 0, 'rgba(255,255,255,1)' );
gradient.addColorStop( 0.2, 'rgba(0,255,255,1)' );
gradient.addColorStop( 0.4, 'rgba(0,0,64,1)' );
gradient.addColorStop( 1, 'rgba(0,0,0,1)' );*/
gradient.addColorStop( 0, 'rgba(255,255,255,1)' );
gradient.addColorStop( 0.6, 'rgba(0,255,255,.5)' );
gradient.addColorStop( 0.8, 'rgba(0,53,169,1)' );
gradient.addColorStop( 1, 'rgba(0,0,0,1)' );
//填充方式
context.fillStyle = gradient;
//填充矩形
context.fillRect( 0, 0, canvas.width, canvas.height );
return canvas;
}
/**
* 粒子 延迟发散
* @param particle
* @param delay
*/
function initParticle( particle, delay ) {
//粒子
var particle = this instanceof THREE.Sprite ? this : particle;
var delay = delay !== undefined ? delay : 0;
//粒子大小以及位置
particle.position.set( 0, 0, 0 );
particle.scale.x = particle.scale.y = Math.random() * 32 + 16;
//下面是一系列的动画
var xx = Math.random()* 400 -200;
var yy = -Math.cos((Math.PI/400) * xx)*500;
//位移
new TWEEN.Tween( particle.position )
.delay( delay )
// .to( { x: Math.random() * 4000 - 2000, y: Math.random() * 1000 - 500, z: Math.random() * 4000 - 2000 }, 10000 )
.to({x:xx,y:yy,z:Math.random()*-100 + 50},3000)
.start();
//理解为存活时间 x加一个判断
if(Math.abs(xx) > 150){
new TWEEN.Tween(particle)
.delay(delay)
.to({}, 0)
.onComplete(initParticle)
.start();
}else {
new TWEEN.Tween(particle)
.delay(delay)
.to({}, 2000)
.onComplete(initParticle)
.start();
}
//大小
new TWEEN.Tween( particle.scale )
.delay( delay )
.to( { x: 0.01, y: 0.01 }, 2000 )
.start();
}
//
function onDocumentMouseMove( event ) {
mouseX = event.clientX - windowHalfX;
mouseY = event.clientY - windowHalfY;
}
function onDocumentTouchStart( event ) {
if ( event.touches.length == 1 ) {
event.preventDefault();
mouseX = event.touches[ 0 ].pageX - windowHalfX;
mouseY = event.touches[ 0 ].pageY - windowHalfY;
}
}
function onDocumentTouchMove( event ) {
if ( event.touches.length == 1 ) {
event.preventDefault();
mouseX = event.touches[ 0 ].pageX - windowHalfX;
mouseY = event.touches[ 0 ].pageY - windowHalfY;
}
}
//
function animate() {
requestAnimationFrame( animate );
render();
stats.update();
}
var js = 0;
function render() {
TWEEN.update();
camera.position.x += ( mouseX - camera.position.x ) * 0.05;
camera.position.y += ( - mouseY - camera.position.y ) * 0.05;
camera.lookAt( scene.position );
//krq.rotation.x = 2;
//krq.rotation.y = 2;
if(krq.position.z !== 0){
krq.position.z += 1;
krq.position.x -= 1;
}else{
krq.rotation.z = 0;
}
//krq.vertices[1].position.x +=1;
renderer.render( scene, camera );
}
</script>
</body>
</html>
该有的参数都有的，最后的效果
fire
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