今天又要為大家帶來一款超酷的Html5 Canvas 3D動畫特效,是一款可以旋轉的Html5 Logo標志。畫面上一共有兩塊可旋轉的區域,第一是可旋轉的背景,第二則是可旋轉的Logo標志。Logo標志在旋轉的時候還有3D的視覺效果,這一切 我們都是在canvas上實現的。具體演示和實現過程可以看下文。

你也可以在這裡查看在線演示
下面我們來簡單分析一下實現這款3D動畫的過程及其部分核心代碼,主要由Html代碼以及Javascript代碼組成。
Html代碼:
<canvas id="canvas" style="background-color:#ddd"></canvas>
非常簡單,僅僅是構造了一個canvas容器,接下來的3D動畫,包括旋轉的特效都將在這裡繪制和實現。
Javascript代碼:
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);
}
這部分代碼是整個動畫的初始化代碼,其中我們利用了k3d的腳本庫,所以你需要在項目中引用它,關於k3d,你可以在最後的源代碼中找到它。
<script src="k3d-min.JS"></script>
下面是一些鼠標事件,你可以拖動鼠標來讓其旋轉,具體代碼如下:
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,一個簡單的3D動畫實現起來還是有點復雜的,你可以下載源代碼來研究學習。源碼下載