19 回收粒子
2021-12-12 本文已影响0人
skoll
PCS和SPS这种有粒子总数的粒子系统，就需要回收，因为有总数，当粒子运动到视野外，如果需要在此使用这个粒子，就需要回收
<!DOCTYPE html>
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<html>
<head>
<meta http-equiv="Content-Type" content="text/html" charset="utf-8"/>
<title>Babylon - Getting Started</title>
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<style>
html, body {
overflow: hidden;
width : 100%;
height : 100%;
margin : 0;
padding : 0;
}
#renderCanvas {
width : 100%;
height : 100%;
touch-action: none;
}
</style>
<body>
<canvas id="renderCanvas" touch-action="none"></canvas>
<script>
const canvas = document.getElementById("renderCanvas");
var engine = null;
// 这里还不能用let，不然就爆炸，获取不到engine
var scene = null;
var sceneToRender = null;
const createDefaultEngine = function() { return new BABYLON.Engine(canvas, true, { preserveDrawingBuffer: true, stencil: true, disableWebGL2Support: false}); };
let createScene=async function(){
// 关键函数都写在这个里面
var scene = new BABYLON.Scene(engine);
var camera = new BABYLON.ArcRotateCamera("cam", -Math.PI / 2, Math.PI / 2.5,7, BABYLON.Vector3.Zero(), scene);
camera.attachControl(canvas, true);
var light = new BABYLON.HemisphericLight("HemiLight", new BABYLON.Vector3(1, 1, 0), scene);
light.intensity = 0.5;
var myTexture = new BABYLON.Texture("https://img0.baidu.com/it/u=1593955789,3403856786&fm=26&fmt=auto", scene);
// 粒子应用的材质
let pcs=new BABYLON.PointsCloudSystem('pcs',1,scene)
pcs.updateParticle=function(particle){
if(particle.position.y>particle.heightLim){
this.recycleParticle(particle)
}
particle.position.addInPlace(particle.velocity)
}
pcs.recycleParticle = function(particle) {
particle.position = BABYLON.Vector3.Zero();
particle.color = new BABYLON.Color4(Math.random(), Math.random(), Math.random(), Math.random());
particle.velocity = new BABYLON.Vector3(0.2 - 0.4 * Math.random(), 0.25 + 0.25 * Math.random(), 0.2 - 0.4 * Math.random());
particle.heightLim = 4 + 0.5 * Math.random();
}
pcs.addPoints(10000,pcs.recycleParticle)
pcs.buildMeshAsync()
scene.registerBeforeRender(() => pcs.setParticles());
return scene
}
window.initFunction=async function(){
let asyncEngineCreation=async function(){
try{
return createDefaultEngine()
}catch(e){
return createDefaultEngine()
}
}
window.engine=await asyncEngineCreation()
if(!engine){
throw('engine should not be null')
}
window.scene=createScene()
}
initFunction().then(()=>{
scene.then((returnedScene)=>{
sceneToRender=returnedScene
})
engine.runRenderLoop(function(){
if(sceneToRender&&sceneToRender.activeCamera){
sceneToRender.render()
}
})
})
window.addEventListener('resize',function(){
engine.resize()
})
</script>
<body>
