3D HTML5 Logo标志 超炫酷旋转特效

今天又要为大家带来一款超酷的HTML5 Canvas 3D动画特效，是一款可以旋转的HTML5 Logo标志。画面上一共有两块可旋转的区域，第一是可旋转的背景，第二则是可旋转的Logo标志。Logo标志在旋转的时候还有3D的视觉效果，这一切我们都是在canvas上实现的。具体演示和实现过程可以看下文。

你也可以在这里查看在线演示

下面我们来简单分析一下实现这款3D动画的过程及其部分核心代码，主要由HTML代码以及Javascript代码组成。

HTML代码：

<canvas id="canvas" style="background-color:#ddd"></canvas>

非常简单，仅仅是构造了一个canvas容器，接下来的3D动画，包括旋转的特效都将在这里绘制和实现。

Javascript代码：

function onloadHandler()
{
   var canvas = document.getElementById('canvas');
   canvas.width = window.innerWidth;
   canvas.height = window.innerHeight;
   var k3dmain = new K3D.Controller(canvas, true);
   
   // generate 3D objects
   
   var obj1 = new K3D.K3DObject();
   with (obj1)
   {
      drawmode = "solid";
      shademode = "lightsource";
      sortmode = "unsorted";
      addphi = -0.5;
      abouty = -90;
      perslevel = 1000;
      init(
         [{x:-80,y:180,z:0},{x:0,y:180,z:-80},{x:0,y:0,z:-80},{x:-80,y:20,z:0},{x:-50,y:150,z:-30},{x:0,y:150,z:-80},{x:0,y:130,z:-80},{x:-30,y:130,z:-50},{x:-28,y:110,z:-52},{x:0,y:110,z:-80},{x:0,y:90,z:-80},{x:-45,y:90,z:-35},{x:-44,y:80,z:-36},{x:-25,y:80,z:-55},{x:-22,y:66,z:-58},{x:0,y:60,z:-80},{x:0,y:40,z:-80},{x:-40,y:50,z:-40}],
         [],
         [{color:[227,76,38],vertices:[0,1,2,3,0]},{color:[235,235,235],vertices:[4,5,6,7,8,9,10,11,4]},{color:[235,235,235],vertices:[12,13,14,15,16,17,12]}]
      );
   }
   k3dmain.addK3DObject(obj1);
   
   var obj2 = new K3D.K3DObject();
   with (obj2)
   {
      drawmode = "solid";
      shademode = "lightsource";
      sortmode = "unsorted";
      addphi = -0.5;
      abouty = -90;
      perslevel = 1000;
      init(
         [{x:0,y:180,z:-80},{x:80,y:180,z:0},{x:80,y:20,z:0},{x:0,y:0,z:-80},{x:0,y:165,z:-80},{x:68,y:165,z:-12},{x:55,y:35,z:-25},{x:0,y:20,z:-80},{x:0,y:150,z:-80},{x:50,y:150,z:-30},{x:47,y:130,z:-33},{x:0,y:130,z:-80},{x:0,y:110,z:-80},{x:45,y:110,z:-35},{x:40,y:50,z:-40},{x:0,y:40,z:-80},{x:0,y:60,z:-80},{x:20,y:66,z:-60},{x:23,y:90,z:-57},{x:0,y:90,z:-80}],
         [],
         [{color:[227,76,38],vertices:[0,1,2,3,0]},{color:[240,101,41],vertices:[4,5,6,7,4]},{color:[235,235,235],vertices:[8,9,10,11,8]},{color:[235,235,235],vertices:[12,13,14,15,16,17,18,19,12]}]
      );
   }
   k3dmain.addK3DObject(obj2);
   
   var obj3 = new K3D.K3DObject();
   with (obj3)
   {
      drawmode = "solid";
      shademode = "lightsource";
      sortmode = "unsorted";
      addphi = -0.5;
      abouty = -90;
      perslevel = 1000;
      init(
         [{x:80,y:180,z:0},{x:0,y:180,z:80},{x:0,y:0,z:80},{x:80,y:20,z:0},{x:50,y:150,z:30},{x:0,y:150,z:80},{x:0,y:130,z:80},{x:30,y:130,z:50},{x:28,y:110,z:52},{x:0,y:110,z:80},{x:0,y:90,z:80},{x:45,y:90,z:35},{x:44,y:80,z:36},{x:25,y:80,z:55},{x:22,y:66,z:58},{x:0,y:60,z:80},{x:0,y:40,z:80},{x:40,y:50,z:40}],
         [],
         [{color:[227,76,38],vertices:[0,1,2,3,0]},{color:[235,235,235],vertices:[4,5,6,7,8,9,10,11,4]},{color:[235,235,235],vertices:[12,13,14,15,16,17,12]}]
      );
   }
   k3dmain.addK3DObject(obj3);
   
   var obj4 = new K3D.K3DObject();
   with (obj4)
   {
      drawmode = "solid";
      shademode = "lightsource";
      sortmode = "unsorted";
      addphi = -0.5;
      abouty = -90;
      perslevel = 1000;
      init(
         [{x:0,y:180,z:80},{x:-80,y:180,z:0},{x:-80,y:20,z:0},{x:0,y:0,z:80},{x:0,y:165,z:80},{x:-68,y:165,z:12},{x:-55,y:35,z:25},{x:0,y:20,z:80},{x:0,y:150,z:80},{x:-50,y:150,z:30},{x:-47,y:130,z:33},{x:0,y:130,z:80},{x:0,y:110,z:80},{x:-45,y:110,z:35},{x:-40,y:50,z:40},{x:0,y:40,z:80},{x:0,y:60,z:80},{x:-20,y:66,z:60},{x:-23,y:90,z:57},{x:0,y:90,z:80}],
         [],
         [{color:[227,76,38],vertices:[0,1,2,3,0]},{color:[240,101,41],vertices:[4,5,6,7,4]},{color:[235,235,235],vertices:[8,9,10,11,8]},{color:[235,235,235],vertices:[12,13,14,15,16,17,18,19,12]}]
      );
   }
   k3dmain.addK3DObject(obj4);
   
   var objBase = new K3D.K3DObject();
   with (objBase)
   {
      drawmode = "solid";
      shademode = "lightsource";
      sortmode = "unsorted";
      addphi = -0.5;
      abouty = -90;
      perslevel = 1000;
      init(
         [{x:0,y:0,z:-80},{x:-80,y:20,z:0},{x:0,y:0,z:80},{x:80,y:20,z:0}],
         [],
         [{color:[227,76,38],vertices:[0,2,1,0]},{color:[227,76,38],vertices:[0,3,2,0]}]
      );
   }
   k3dmain.addK3DObject(objBase);
   
   var objHtml = new K3D.K3DObject();
   with (objHtml)
   {
      drawmode = "solid";
      shademode = "lightsource";
      //sortmode = "unsorted";
      color = [64,64,64];
      doublesided = true;
      addphi = -0.5;
      abouty = 100;
      scale = 0.75;
      perslevel = 1000;
      init(
         [{x:-80,y:40,z:0},{x:-70,y:40,z:0},{x:-70,y:30,z:0},{x:-60,y:30,z:0},{x:-60,y:40,z:0},{x:-50,y:40,z:0},{x:-50,y:10,z:0},{x:-60,y:10,z:0},{x:-60,y:20,z:0},{x:-70,y:20,z:0},{x:-70,y:10,z:0},{x:-80,y:10,z:0},{x:-40,y:40,z:0},{x:-10,y:40,z:0},{x:-10,y:30,z:0},{x:-20,y:30,z:0},{x:-20,y:10,z:0},{x:-30,y:10,z:0},{x:-30,y:30,z:0},{x:-40,y:30,z:0},{x:0,y:40,z:0},{x:10,y:40,z:0},{x:20,y:30,z:0},{x:30,y:40,z:0},{x:40,y:40,z:0},{x:40,y:10,z:0},{x:30,y:10,z:0},{x:30,y:30,z:0},{x:20,y:20,z:0},{x:10,y:30,z:0},{x:10,y:10,z:0},{x:0,y:10,z:0},{x:50,y:40,z:0},{x:60,y:40,z:0},{x:60,y:20,z:0},{x:80,y:20,z:0},{x:80,y:10,z:0},{x:50,y:10,z:0}],
         [],
         [{vertices:[0,1,2,3,4,5,6,7,8,9,10,11,0]},{vertices:[12,13,14,15,16,17,18,19,12]},{vertices:[20,21,22,23,24,25,26,27,28,29,30,31,20]},{vertices:[32,33,34,35,36,37,32]}]
      );
   }
   k3dmain.addK3DObject(objHtml);
   
   // add render loop callback
   var ctx = canvas.getContext('2d');
   var rotationOffset = 0;
   var len = (canvas.height > canvas.width ? canvas.height : canvas.width) * 0.7;
   k3dmain.clearBackground = false;
   k3dmain.callback = function()
   {
      // manually clear bg - as we want to render some extra goodies
      ctx.clearRect(0, 0, canvas.width, canvas.height);
      
      // draw bg effect before K3D does its 3D rendering
      ctx.save();
      ctx.translate(canvas.width/2, canvas.height/2);
      ctx.rotate(rotationOffset);
      
      // first fill pass - outer rays
      var RAYCOUNT = 24;
      ctx.fillStyle = "#eee";
      ctx.beginPath();
      for (var i=0; i<RAYCOUNT; i++)
      {
         // rotate context
         ctx.rotate(TWOPI / RAYCOUNT);
         ctx.moveTo(0, 0);
         ctx.lineTo(-20, len);
         ctx.lineTo(20, len);
      }
      ctx.closePath();
      ctx.fill();
      // second fill pass - inner rays
      ctx.fillStyle = "#fff";
      ctx.beginPath();
      for (var i=0; i<RAYCOUNT; i++)
      {
         // rotate context
         ctx.rotate(TWOPI / RAYCOUNT);
         ctx.moveTo(0, 0);
         ctx.lineTo(-15, len);
         ctx.lineTo(15, len);
      }
      ctx.closePath();
      ctx.fill();
      ctx.restore();
      rotationOffset += 0.005;
      
      // apply user interaction to rotation
      for (var i=0, objs=k3dmain.objects; i<objs.length; i++)
      {
         objs[i].ophi += targetRotationX;
      }
      
      if (targetRotationX > -0.5) targetRotationX -= 0.05;
      else if (targetRotationX < -0.55) targetRotationX += 0.05;
      if (targetRotationX > -0.55 && targetRotationX < -0.5) targetRotationX = -0.5;
   };
   
   // start demo loop
   k3dmain.paused = true;
   setInterval(function(){k3dmain.tick()}, 1000/60);
}

这部分代码是整个动画的初始化代码，其中我们利用了k3d的脚本库，所以你需要在项目中引用它，关于k3d，你可以在最后的源代码中找到它。

<script src="k3d-min.js"></script>

下面是一些鼠标事件，你可以拖动鼠标来让其旋转，具体代码如下：

function onDocumentMouseDown( event ) {

    event.preventDefault();
    
    document.addEventListener('mousemove', onDocumentMouseMove, false);
    document.addEventListener('mouseup', onDocumentMouseUp, false);
    document.addEventListener('mouseout', onDocumentMouseOut, false);
    
    mouseXOnMouseDown = event.clientX - windowHalfX;
    targetRotationOnMouseDownX = targetRotationX;
    mouseYOnMouseDown = event.clientY - windowHalfY;
    targetRotationOnMouseDownY = targetRotationY;
}

function onDocumentMouseMove( event )
{
    mouseX = event.clientX - windowHalfX;
    targetRotationX = targetRotationOnMouseDownX + (mouseX - mouseXOnMouseDown) * 0.02;
    mouseY = event.clientY - windowHalfY;
    targetRotationY = targetRotationOnMouseDownY + (mouseY - mouseYOnMouseDown) * 0.02;
}

function onDocumentMouseUp( event )
{
    document.removeEventListener('mousemove', onDocumentMouseMove, false);
    document.removeEventListener('mouseup', onDocumentMouseUp, false);
    document.removeEventListener('mouseout', onDocumentMouseOut, false);
}

function onDocumentMouseOut( event )
{
    document.removeEventListener('mousemove', onDocumentMouseMove, false);
    document.removeEventListener('mouseup', onDocumentMouseUp, false);
    document.removeEventListener('mouseout', onDocumentMouseOut, false);
}

function onDocumentTouchStart( event )
{
    if (event.touches.length == 1)
    {
        event.preventDefault();

        mouseXOnMouseDown = event.touches[0].pageX - windowHalfX;
        targetRotationOnMouseDownX = targetRotationX;
        mouseYOnMouseDown = event.touches[0].pageY - windowHalfY;
        targetRotationOnMouseDownY = targetRotationY;
    }
}

好了，一个简单的3D动画实现起来还是有点复杂的，你可以下载源代码来研究学习。源码下载>>