漩涡粒子

你的名字 2022-05-24 03:43 161阅读 0赞

相必各位同学们看过许多酷炫的用JS实现的3D漩涡吧，下面我为大家安利一下源码：

<!doctype html>
    <html>
    <head>
    <meta charset="utf-8">
    <title>漩涡粒子</title>
    
    <style>
    html,body{
    	margin:0px;
    	width:100%;
    	height:100%;
    	overflow:hidden;
      background:#000;
    }
    
    #canvas{
    	position:absolute;
    	width:100%;
    	height:100%;
    }
    </style>
    </head>
    <body>
    
    <canvas id="canvas"></canvas>
    
    <script>
    function project3D(x,y,z,vars){
    
    	var p,d;
    	x-=vars.camX;
    	y-=vars.camY-8;
    	z-=vars.camZ;
    	p=Math.atan2(x,z);
    	d=Math.sqrt(x*x+z*z);
    	x=Math.sin(p-vars.yaw)*d;
    	z=Math.cos(p-vars.yaw)*d;
    	p=Math.atan2(y,z);
    	d=Math.sqrt(y*y+z*z);
    	y=Math.sin(p-vars.pitch)*d;
    	z=Math.cos(p-vars.pitch)*d;
    	var rx1=-1000;
    	var ry1=1;
    	var rx2=1000;
    	var ry2=1;
    	var rx3=0;
    	var ry3=0;
    	var rx4=x;
    	var ry4=z;
    	var uc=(ry4-ry3)*(rx2-rx1)-(rx4-rx3)*(ry2-ry1);
    	var ua=((rx4-rx3)*(ry1-ry3)-(ry4-ry3)*(rx1-rx3))/uc;
    	var ub=((rx2-rx1)*(ry1-ry3)-(ry2-ry1)*(rx1-rx3))/uc;
    	if(!z)z=0.000000001;
    	if(ua>0&&ua<1&&ub>0&&ub<1){
    		return {
    			x:vars.cx+(rx1+ua*(rx2-rx1))*vars.scale,
    			y:vars.cy+y/z*vars.scale,
    			d:(x*x+y*y+z*z)
    		};
    	}else{
    		return { d:-1 };
    	}
    }
    
    
    function elevation(x,y,z){
    
    	var dist = Math.sqrt(x*x+y*y+z*z);
    	if(dist && z/dist>=-1 && z/dist <=1) return Math.acos(z / dist);
    	return 0.00000001;
    }
    
    
    function rgb(col){
    
    	col += 0.000001;
    	var r = parseInt((0.5+Math.sin(col)*0.5)*16);
    	var g = parseInt((0.5+Math.cos(col)*0.5)*16);
    	var b = parseInt((0.5-Math.sin(col)*0.5)*16);
    	return "#"+r.toString(16)+g.toString(16)+b.toString(16);
    }
    
    
    function interpolateColors(RGB1,RGB2,degree){
    	
    	var w2=degree;
    	var w1=1-w2;
    	return [w1*RGB1[0]+w2*RGB2[0],w1*RGB1[1]+w2*RGB2[1],w1*RGB1[2]+w2*RGB2[2]];
    }
    
    
    function rgbArray(col){
    
    	col += 0.000001;
    	var r = parseInt((0.5+Math.sin(col)*0.5)*256);
    	var g = parseInt((0.5+Math.cos(col)*0.5)*256);
    	var b = parseInt((0.5-Math.sin(col)*0.5)*256);
    	return [r, g, b];
    }
    
    
    function colorString(arr){
    
    	var r = parseInt(arr[0]);
    	var g = parseInt(arr[1]);
    	var b = parseInt(arr[2]);
    	return "#"+("0" + r.toString(16) ).slice (-2)+("0" + g.toString(16) ).slice (-2)+("0" + b.toString(16) ).slice (-2);
    }
    
    
    function process(vars){
    
    
    	if(vars.points.length<vars.initParticles) for(var i=0;i<5;++i) spawnParticle(vars);
    	var p,d,t;
    	
    	p = Math.atan2(vars.camX, vars.camZ);
    	d = Math.sqrt(vars.camX * vars.camX + vars.camZ * vars.camZ);
    	d -= Math.sin(vars.frameNo / 80) / 25;
    	t = Math.cos(vars.frameNo / 300) / 165;
    	vars.camX = Math.sin(p + t) * d;
    	vars.camZ = Math.cos(p + t) * d;
    	vars.camY = -Math.sin(vars.frameNo / 220) * 15;
    	vars.yaw = Math.PI + p + t;
    	vars.pitch = elevation(vars.camX, vars.camZ, vars.camY) - Math.PI / 2;
    	
    	var t;
    	for(var i=0;i<vars.points.length;++i){
    		
    		x=vars.points[i].x;
    		y=vars.points[i].y;
    		z=vars.points[i].z;
    		d=Math.sqrt(x*x+z*z)/1.0075;
    		t=.1/(1+d*d/5);
    		p=Math.atan2(x,z)+t;
    		vars.points[i].x=Math.sin(p)*d;
    		vars.points[i].z=Math.cos(p)*d;
    		vars.points[i].y+=vars.points[i].vy*t*((Math.sqrt(vars.distributionRadius)-d)*2);
    		if(vars.points[i].y>vars.vortexHeight/2 || d<.25){
    			vars.points.splice(i,1);
    			spawnParticle(vars);
    		}
    	}
    }
    
    function drawFloor(vars){
    	
    	var x,y,z,d,point,a;
    	for (var i = -25; i <= 25; i += 1) {
    		for (var j = -25; j <= 25; j += 1) {
    			x = i*2;
    			z = j*2;
    			y = vars.floor;
    			d = Math.sqrt(x * x + z * z);
    			point = project3D(x, y-d*d/85, z, vars);
    			if (point.d != -1) {
    				size = 1 + 15000 / (1 + point.d);
    				a = 0.15 - Math.pow(d / 50, 4) * 0.15;
    				if (a > 0) {
    					vars.ctx.fillStyle = colorString(interpolateColors(rgbArray(d/26-vars.frameNo/40),[0,128,32],.5+Math.sin(d/6-vars.frameNo/8)/2));
    					vars.ctx.globalAlpha = a;
    					vars.ctx.fillRect(point.x-size/2,point.y-size/2,size,size);
    				}
    			}
    		}
    	}		
    	vars.ctx.fillStyle = "#82f";
    	for (var i = -25; i <= 25; i += 1) {
    		for (var j = -25; j <= 25; j += 1) {
    			x = i*2;
    			z = j*2;
    			y = -vars.floor;
    			d = Math.sqrt(x * x + z * z);
    			point = project3D(x, y+d*d/85, z, vars);
    			if (point.d != -1) {
    				size = 1 + 15000 / (1 + point.d);
    				a = 0.15 - Math.pow(d / 50, 4) * 0.15;
    				if (a > 0) {
    					vars.ctx.fillStyle = colorString(interpolateColors(rgbArray(-d/26-vars.frameNo/40),[32,0,128],.5+Math.sin(-d/6-vars.frameNo/8)/2));
    					vars.ctx.globalAlpha = a;
    					vars.ctx.fillRect(point.x-size/2,point.y-size/2,size,size);
    				}
    			}
    		}
    	}		
    }
    
    function sortFunction(a,b){
    	return b.dist-a.dist;
    }
    
    function draw(vars){
    
    	vars.ctx.globalAlpha=.15;
    	vars.ctx.fillStyle="#000";
    	vars.ctx.fillRect(0, 0, canvas.width, canvas.height);
    	
    	drawFloor(vars);
    	
    	var point,x,y,z,a;
    	for(var i=0;i<vars.points.length;++i){
    		x=vars.points[i].x;
    		y=vars.points[i].y;
    		z=vars.points[i].z;
    		point=project3D(x,y,z,vars);
    		if(point.d != -1){
    			vars.points[i].dist=point.d;
    			size=1+vars.points[i].radius/(1+point.d);
    			d=Math.abs(vars.points[i].y);
    			a = .8 - Math.pow(d / (vars.vortexHeight/2), 1000) * .8;
    			vars.ctx.globalAlpha=a>=0&&a<=1?a:0;
    			vars.ctx.fillStyle=rgb(vars.points[i].color);
    			if(point.x>-1&&point.x<vars.canvas.width&&point.y>-1&&point.y<vars.canvas.height)vars.ctx.fillRect(point.x-size/2,point.y-size/2,size,size);
    		}
    	}
    	vars.points.sort(sortFunction);
    }
    
    
    function spawnParticle(vars){
    
    	var p,ls;
    	pt={};
    	p=Math.PI*2*Math.random();
    	ls=Math.sqrt(Math.random()*vars.distributionRadius);
    	pt.x=Math.sin(p)*ls;
    	pt.y=-vars.vortexHeight/2;
    	pt.vy=vars.initV/20+Math.random()*vars.initV;
    	pt.z=Math.cos(p)*ls;
    	pt.radius=200+800*Math.random();
    	pt.color=pt.radius/1000+vars.frameNo/250;
    	vars.points.push(pt);	
    }
    
    function frame(vars) {
    
    	if(vars === undefined){
    		var vars={};
    		vars.canvas = document.querySelector("canvas");
    		vars.ctx = vars.canvas.getContext("2d");
    		vars.canvas.width = document.body.clientWidth;
    		vars.canvas.height = document.body.clientHeight;
    		window.addEventListener("resize", function(){
    			vars.canvas.width = document.body.clientWidth;
    			vars.canvas.height = document.body.clientHeight;
    			vars.cx=vars.canvas.width/2;
    			vars.cy=vars.canvas.height/2;
    		}, true);
    		vars.frameNo=0;
    
    		vars.camX = 0;
    		vars.camY = 0;
    		vars.camZ = -14;
    		vars.pitch = elevation(vars.camX, vars.camZ, vars.camY) - Math.PI / 2;
    		vars.yaw = 0;
    		vars.cx=vars.canvas.width/2;
    		vars.cy=vars.canvas.height/2;
    		vars.bounding=10;
    		vars.scale=500;
    		vars.floor=26.5;
    
    		vars.points=[];
    		vars.initParticles=700;
    		vars.initV=.01;
    		vars.distributionRadius=800;
    		vars.vortexHeight=25;
    	}
    
    	vars.frameNo++;
    	requestAnimationFrame(function() {
    		frame(vars);
    	});
    
    	process(vars);
    	draw(vars);
    }
    frame();
    </script>
    <div style="text-align:center;">
    <p>来源:<a href="http://www.mycodes.net/" target="_blank">漩涡粒子</a></p>
    </div>
    </body>
    </html>