This article will introduce to you through examples how to use JS to achieve super beautiful 3D fireworks effects? It has certain reference value. Friends in need can refer to it. I hope it will be helpful to everyone.
Without further ado, let’s go straight to the code:
<!doctype html>
<html>
<head>
<meta charset="utf-8">
<title>3D烟花</title>
<style>
html,body{
margin:0px;
width:100%;
height:100%;
overflow:hidden;
background:#000;
}
#canvas{
width:100%;
height:100%;
}
</style>
</head>
<body>
<canvas id="canvas"></canvas><script>
function initVars(){
pi=Math.PI;
ctx=canvas.getContext("2d");
canvas.width=canvas.clientWidth;
canvas.height=canvas.clientHeight;
cx=canvas.width/2;
cy=canvas.height/2;
playerZ=-25;
playerX=playerY=playerVX=playerVY=playerVZ=pitch=yaw=pitchV=yawV=0;
scale=600;
seedTimer=0;seedInterval=5,seedLife=100;gravity=.02;
seeds=new Array();
sparkPics=new Array();
s="https://cantelope.org/NYE/";
for(i=1;i<=10;++i){
sparkPic=new Image();
sparkPic.src=s+"spark"+i+".png";
sparkPics.push(sparkPic);
}
sparks=new Array();
pow1=new Audio(s+"pow1.ogg");
pow2=new Audio(s+"pow2.ogg");
pow3=new Audio(s+"pow3.ogg");
pow4=new Audio(s+"pow4.ogg");
frames = 0;
}
function rasterizePoint(x,y,z){
var p,d;
x-=playerX;
y-=playerY;
z-=playerZ;
p=Math.atan2(x,z);
d=Math.sqrt(x*x+z*z);
x=Math.sin(p-yaw)*d;
z=Math.cos(p-yaw)*d;
p=Math.atan2(y,z);
d=Math.sqrt(y*y+z*z);
y=Math.sin(p-pitch)*d;
z=Math.cos(p-pitch)*d;
var rx1=-1000,ry1=1,rx2=1000,ry2=1,rx3=0,ry3=0,rx4=x,ry4=z,uc=(ry4-ry3)*(rx2-rx1)-(rx4-rx3)*(ry2-ry1);
if(!uc) return {x:0,y:0,d:-1};
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=.000000001;
if(ua>0&&ua<1&&ub>0&&ub<1){
return {
x:cx+(rx1+ua*(rx2-rx1))*scale,
y:cy+y/z*scale,
d:Math.sqrt(x*x+y*y+z*z)
};
}else{
return {
x:cx+(rx1+ua*(rx2-rx1))*scale,
y:cy+y/z*scale,
d:-1
};
}
}
function spawnSeed(){
seed=new Object();
seed.x=-50+Math.random()*100;
seed.y=25;
seed.z=-50+Math.random()*100;
seed.vx=.1-Math.random()*.2;
seed.vy=-1.5;//*(1+Math.random()/2);
seed.vz=.1-Math.random()*.2;
seed.born=frames;
seeds.push(seed);
}
function splode(x,y,z){
t=5+parseInt(Math.random()*150);
sparkV=1+Math.random()*2.5;
type=parseInt(Math.random()*3);
switch(type){
case 0:
pic1=parseInt(Math.random()*10);
break;
case 1:
pic1=parseInt(Math.random()*10);
do{ pic2=parseInt(Math.random()*10); }while(pic2==pic1);
break;
case 2:
pic1=parseInt(Math.random()*10);
do{ pic2=parseInt(Math.random()*10); }while(pic2==pic1);
do{ pic3=parseInt(Math.random()*10); }while(pic3==pic1 || pic3==pic2);
break;
}
for(m=1;m<t;++m){
spark=new Object();
spark.x=x; spark.y=y; spark.z=z;
p1=pi*2*Math.random();
p2=pi*Math.random();
v=sparkV*(1+Math.random()/6)
spark.vx=Math.sin(p1)*Math.sin(p2)*v;
spark.vz=Math.cos(p1)*Math.sin(p2)*v;
spark.vy=Math.cos(p2)*v;
switch(type){
case 0: spark.img=sparkPics[pic1]; break;
case 1:
spark.img=sparkPics[parseInt(Math.random()*2)?pic1:pic2];
break;
case 2:
switch(parseInt(Math.random()*3)){
case 0: spark.img=sparkPics[pic1]; break;
case 1: spark.img=sparkPics[pic2]; break;
case 2: spark.img=sparkPics[pic3]; break;
}
break;
}
spark.radius=25+Math.random()*50;
spark.alpha=1;
spark.trail=new Array();
sparks.push(spark);
}
switch(parseInt(Math.random()*4)){
case 0: pow=new Audio(s+"pow1.ogg"); break;
case 1: pow=new Audio(s+"pow2.ogg"); break;
case 2: pow=new Audio(s+"pow3.ogg"); break;
case 3: pow=new Audio(s+"pow4.ogg"); break;
}
d=Math.sqrt((x-playerX)*(x-playerX)+(y-playerY)*(y-playerY)+(z-playerZ)*(z-playerZ));
pow.volume=1.5/(1+d/10);
pow.play();
}
function doLogic(){
if(seedTimer<frames){
seedTimer=frames+seedInterval*Math.random()*10;
spawnSeed();
}
for(i=0;i<seeds.length;++i){
seeds[i].vy+=gravity;
seeds[i].x+=seeds[i].vx;
seeds[i].y+=seeds[i].vy;
seeds[i].z+=seeds[i].vz;
if(frames-seeds[i].born>seedLife){
splode(seeds[i].x,seeds[i].y,seeds[i].z);
seeds.splice(i,1);
}
}
for(i=0;i<sparks.length;++i){
if(sparks[i].alpha>0 && sparks[i].radius>5){
sparks[i].alpha-=.01;
sparks[i].radius/=1.02;
sparks[i].vy+=gravity;
point=new Object();
point.x=sparks[i].x;
point.y=sparks[i].y;
point.z=sparks[i].z;
if(sparks[i].trail.length){
x=sparks[i].trail[sparks[i].trail.length-1].x;
y=sparks[i].trail[sparks[i].trail.length-1].y;
z=sparks[i].trail[sparks[i].trail.length-1].z;
d=((point.x-x)*(point.x-x)+(point.y-y)*(point.y-y)+(point.z-z)*(point.z-z));
if(d>9){
sparks[i].trail.push(point);
}
}else{
sparks[i].trail.push(point);
}
if(sparks[i].trail.length>5)sparks[i].trail.splice(0,1);
sparks[i].x+=sparks[i].vx;
sparks[i].y+=sparks[i].vy;
sparks[i].z+=sparks[i].vz;
sparks[i].vx/=1.075;
sparks[i].vy/=1.075;
sparks[i].vz/=1.075;
}else{
sparks.splice(i,1);
}
}
p=Math.atan2(playerX,playerZ);
d=Math.sqrt(playerX*playerX+playerZ*playerZ);
d+=Math.sin(frames/80)/1.25;
t=Math.sin(frames/200)/40;
playerX=Math.sin(p+t)*d;
playerZ=Math.cos(p+t)*d;
yaw=pi+p+t;
}
function rgb(col){
var r = parseInt((.5+Math.sin(col)*.5)*16);
var g = parseInt((.5+Math.cos(col)*.5)*16);
var b = parseInt((.5-Math.sin(col)*.5)*16);
return "#"+r.toString(16)+g.toString(16)+b.toString(16);
}
function draw(){
ctx.clearRect(0,0,cx*2,cy*2);
ctx.fillStyle="#ff8";
for(i=-100;i<100;i+=3){
for(j=-100;j<100;j+=4){
x=i;z=j;y=25;
point=rasterizePoint(x,y,z);
if(point.d!=-1){
size=250/(1+point.d);
d = Math.sqrt(x * x + z * z);
a = 0.75 - Math.pow(d / 100, 6) * 0.75;
if(a>0){
ctx.globalAlpha = a;
ctx.fillRect(point.x-size/2,point.y-size/2,size,size);
}
}
}
}
ctx.globalAlpha=1;
for(i=0;i<seeds.length;++i){
point=rasterizePoint(seeds[i].x,seeds[i].y,seeds[i].z);
if(point.d!=-1){
size=200/(1+point.d);
ctx.fillRect(point.x-size/2,point.y-size/2,size,size);
}
}
point1=new Object();
for(i=0;i<sparks.length;++i){
point=rasterizePoint(sparks[i].x,sparks[i].y,sparks[i].z);
if(point.d!=-1){
size=sparks[i].radius*200/(1+point.d);
if(sparks[i].alpha<0)sparks[i].alpha=0;
if(sparks[i].trail.length){
point1.x=point.x;
point1.y=point.y;
switch(sparks[i].img){
case sparkPics[0]:ctx.strokeStyle="#f84";break;
case sparkPics[1]:ctx.strokeStyle="#84f";break;
case sparkPics[2]:ctx.strokeStyle="#8ff";break;
case sparkPics[3]:ctx.strokeStyle="#fff";break;
case sparkPics[4]:ctx.strokeStyle="#4f8";break;
case sparkPics[5]:ctx.strokeStyle="#f44";break;
case sparkPics[6]:ctx.strokeStyle="#f84";break;
case sparkPics[7]:ctx.strokeStyle="#84f";break;
case sparkPics[8]:ctx.strokeStyle="#fff";break;
case sparkPics[9]:ctx.strokeStyle="#44f";break;
}
for(j=sparks[i].trail.length-1;j>=0;--j){
point2=rasterizePoint(sparks[i].trail[j].x,sparks[i].trail[j].y,sparks[i].trail[j].z);
if(point2.d!=-1){
ctx.globalAlpha=j/sparks[i].trail.length*sparks[i].alpha/2;
ctx.beginPath();
ctx.moveTo(point1.x,point1.y);
ctx.lineWidth=1+sparks[i].radius*10/(sparks[i].trail.length-j)/(1+point2.d);
ctx.lineTo(point2.x,point2.y);
ctx.stroke();
point1.x=point2.x;
point1.y=point2.y;
}
}
}
ctx.globalAlpha=sparks[i].alpha;
ctx.drawImage(sparks[i].img,point.x-size/2,point.y-size/2,size,size);
}
}
}
function frame(){
if(frames>100000){
seedTimer=0;
frames=0;
}
frames++;
draw();
doLogic();
requestAnimationFrame(frame);
}
window.addEventListener("resize",()=>{
canvas.width=canvas.clientWidth;
canvas.height=canvas.clientHeight;
cx=canvas.width/2;
cy=canvas.height/2;
});
initVars();
frame();</script>
<div style="text-align:center;">
</div>
</body>
</html>
For more related knowledge, please visit javascript study guide ! !
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