最近研究魔方的玩法，就突然想用hmtl5写一个魔方的模型，由于魔方是一个3d的立方体，这次就试着用html5写了一个简单的3d模型。
下面是预览画面。
制作流程
首先你需要下载html5开源库件lufylegend-1.4.0
魔方分为6个面，每个面由9个小矩形组成，现在我把每个小矩形当做一个类封装起来，
因为现在建立的是一个3d魔方，所以要画出每个小矩形，需要知道小矩形的4个定点，而这4个定点会根据空间的旋转角度而变换，所以为了计算出这4个定点坐标，需要知道魔方绕x轴和z轴旋转的角度。
所以，建立矩形类如下
function rect(pointa,pointb,pointc,pointd,anglex,anglez,color){
base(this,lsprite,[]);
this.pointz=[(pointa[0]+pointb[0]+pointc[0]+pointd[0])/4,(pointa[1]+pointb[1]+pointc[1]+pointd[1])/4,(pointa[2]+pointb[2]+pointc[2]+pointd[2])/4];
this.z = this.pointz[2];
this.pointa=pointa,this.pointb=pointb,this.pointc=pointc,this.pointd=pointd,this.anglex=anglex,this.anglez=anglez,this.color=color;
}
rect.prototype.setangle = function(a,b){
this.anglex = a;
this.anglez = b;
this.z=this.getpoint(this.pointz)[2];
};
pointa,pointb,pointc,pointd是小矩形的四个顶点，anglex,anglez分别是x轴和z轴旋转的角度，color是小矩形的颜色。
魔方分为6个面，先看一下最前面的一面，如果以立方体的中心作为3d坐标系的中心，那么9个小矩形的各个定点所对应的坐标如下图所示
所以，前面这个面的9个小矩形可以由下面的代码来建立
for(var x=0;x<3;x++){
for(var y=0;y<3;y++){
z = 3;
var rect = new rect([-3*step + x*2*step,-3*step + y*2*step,-3*step + z*2*step],[-step + x*2*step,-3*step + y*2*step,-3*step + z*2*step],
[-step + x*2*step,-step + y*2*step,-3*step + z*2*step],[-3*step + x*2*step,-step + y*2*step,-3*step + z*2*step],0,0,"#ff0000");
backlayer.addchild(rect);
}
}
其中backlayer是一个lsprite类，step是半个小矩形的长，同样的道理，可以也得到其他5个面。
6个面都建立了，在绘制这6个面之前，首先要根据旋转的角度来计算各个定点的坐标，看下面的图
根据上面的图，用下面的公式即可得到变换后的定点坐标
rect.prototype.getpoint = function(p){
var u2,v2,w2,u=p[0],v=p[1],w=p[2];
u2 = u * math.cos(this.anglex) - v * math.sin(this.anglex);
v2 = u * math.sin(this.anglex) + v * math.cos(this.anglex);
w2 = w;
u = u2; v = v2; w = w2;
u2 = u;
v2 = v * math.cos(this.anglez) - w * math.sin(this.anglez);
w2 = v * math.sin(this.anglez) + w * math.cos(this.anglez);
u = u2; v = v2; w = w2;
return [u2,v2,w2];
};
最后根据小矩形的四个定点坐标，来绘制这个矩形，
rect.prototype.draw = function(layer){
this.graphics.clear();
this.graphics.drawvertices(1,"#000000",[this.getpoint(this.pointa),this.getpoint(this.pointb),
this.getpoint(this.pointc),this.getpoint(this.pointd)],true,this.color);
};
其中drawvertices是lufylegend.js库件中lgraphics类的一个方法，它可以根据传入的定点坐标数组来绘制一个多边形。
最后，给出完整代码，代码很少，js代码一共91行。
一，index.html
<!doctype html>
<html>
<head>
<meta charset="utf-8">
<title>3d魔方</title>
</head>
<body>
<p id="mylegend">loading……</p>
<script type="text/javascript" src="../lufylegend-1.4.0.min.js"></script>
<script type="text/javascript" src="./main.js"></script>
<script type="text/javascript" src="./rect.js"></script>
</body>
</html>
二，rect类
function rect(pointa,pointb,pointc,pointd,anglex,anglez,color){
base(this,lsprite,[]);
this.pointz=[(pointa[0]+pointb[0]+pointc[0]+pointd[0])/4,(pointa[1]+pointb[1]+pointc[1]+pointd[1])/4,(pointa[2]+pointb[2]+pointc[2]+pointd[2])/4];
this.z = this.pointz[2];
this.pointa=pointa,this.pointb=pointb,this.pointc=pointc,this.pointd=pointd,this.anglex=anglex,this.anglez=anglez,this.color=color;
}
rect.prototype.draw = function(layer){
this.graphics.clear();
this.graphics.drawvertices(1,"#000000",[this.getpoint(this.pointa),this.getpoint(this.pointb),
this.getpoint(this.pointc),this.getpoint(this.pointd)],true,this.color);
};rect.prototype.setangle = function(a,b){
this.anglex = a;
this.anglez = b;
this.z=this.getpoint(this.pointz)[2];
};
rect.prototype.getpoint = function(p){
var u2,v2,w2,u=p[0],v=p[1],w=p[2];
u2 = u * math.cos(this.anglex) - v * math.sin(this.anglex);
v2 = u * math.sin(this.anglex) + v * math.cos(this.anglex);
w2 = w;
u = u2; v = v2; w = w2;
u2 = u;
v2 = v * math.cos(this.anglez) - w * math.sin(this.anglez);
w2 = v * math.sin(this.anglez) + w * math.cos(this.anglez);
u = u2; v = v2; w = w2;
return [u2,v2,w2];
};
三，main.js
init(50,"mylegend",400,400,main);
var a = 0,b=0,backlayer,step = 20,key = null;
function main(){
backlayer = new lsprite();
addchild(backlayer);
backlayer.x = 120,backlayer.y = 120;
//后
for(var x=0;x<3;x++){
for(var y=0;y<3;y++){
z = 0;
var rect = new rect([-3*step + x*2*step,-3*step + y*2*step,-3*step + z*2*step],[-step + x*2*step,-3*step + y*2*step,-3*step + z*2*step],
[-step + x*2*step,-step + y*2*step,-3*step + z*2*step],[-3*step + x*2*step,-step + y*2*step,-3*step + z*2*step],0,0,"#ff4500");
backlayer.addchild(rect);
}
}
//前
for(var x=0;x<3;x++){
for(var y=0;y<3;y++){
z = 3;
var rect = new rect([-3*step + x*2*step,-3*step + y*2*step,-3*step + z*2*step],[-step + x*2*step,-3*step + y*2*step,-3*step + z*2*step],
[-step + x*2*step,-step + y*2*step,-3*step + z*2*step],[-3*step + x*2*step,-step + y*2*step,-3*step + z*2*step],0,0,"#ff0000");
backlayer.addchild(rect);
}
}
//上
for(var x=0;x<3;x++){
for(var z=0;z<3;z++){
y = 0;
var rect = new rect([-3*step + x*2*step,-3*step + y*2*step,-3*step + z*2*step],[-step + x*2*step,-3*step + y*2*step,-3*step + z*2*step],
[-step + x*2*step,-3*step + y*2*step,-step + z*2*step],[-3*step + x*2*step,-3*step + y*2*step,-step + z*2*step],0,0,"#ffffff");
backlayer.addchild(rect);
}
}
//下
for(var x=0;x<3;x++){
for(var z=0;z<3;z++){
y = 3;
var rect = new rect([-3*step + x*2*step,-3*step + y*2*step,-3*step + z*2*step],[-step + x*2*step,-3*step + y*2*step,-3*step + z*2*step],
[-step + x*2*step,-3*step + y*2*step,-step + z*2*step],[-3*step + x*2*step,-3*step + y*2*step,-step + z*2*step],0,0,"#ffff00");
backlayer.addchild(rect);
}
}
//左
for(var y=0;y<3;y++){
for(var z=0;z<3;z++){
x = 0;
var rect = new rect([-3*step + x*2*step,-3*step + y*2*step,-3*step + z*2*step],[-3*step + x*2*step,-3*step + y*2*step,-step + z*2*step],
[-3*step + x*2*step,-step + y*2*step,-step + z*2*step],[-3*step + x*2*step,-step + y*2*step,-3*step + z*2*step],0,0,"#008000");
backlayer.addchild(rect);
}
}
//右
for(var y=0;y<3;y++){
for(var z=0;z<3;z++){
x = 3;
var rect = new rect([-3*step + x*2*step,-3*step + y*2*step,-3*step + z*2*step],[-3*step + x*2*step,-3*step + y*2*step,-step + z*2*step],
[-3*step + x*2*step,-step + y*2*step,-step + z*2*step],[-3*step + x*2*step,-step + y*2*step,-3*step + z*2*step],0,0,"#0000ff");
backlayer.addchild(rect);
}
}
backlayer.addeventlistener(levent.enter_frame,onframe);
}
function onframe(){
a += 0.1 , b += 0.1;
backlayer.childlist = backlayer.childlist.sort(function(a,b){return a.z - b.z;});
for(key in backlayer.childlist){
backlayer.childlist[key].setangle(a,b);
backlayer.childlist[key].draw(backlayer);
}
}
以上就是【html5】3d模型--百行代码实现旋转立体魔方实例 的内容。