【HTML5】3D模型--百行代码实现旋转立体魔方实例

2017-01-12 07:50:11来源:作者:人点击

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>  <div id="mylegend">loading……</div>  <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);     }  }  

这只是一个非常简陋的3D模型,希望对大家的学习有所帮助,也希望大家多多支持第七城市。

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