Flash AS3代码绘制旋转的3D立体菜单动画效果

在这篇教程里，我们将学会如何利用Flash AS3代码绘制旋转的3D立体菜单动画效果，教木马将会根据鼠标决定旋转速度。教程绘制效果非常酷，转发过来，感兴趣的朋友快点来学习吧。
演示：

绘制步骤：

1、新建Flash文件,设置宽、高属性为 550 × 400 。

2、用圆角矩形工具，画一个 158 × 35的长方形。笔触为8白色，填充色#0 F7E 88。图1：

3、将长方形转换成名为  Menu Item  的影片剪辑。设定注册点为中心。图2：

4、双击舞台上的影片剪辑，进入编辑状态。创建动态文本，在它里面输入需要的本文。图3

5、在属性面板中输入实例名字  menuItemText 。

6、按下字符嵌入按钮，插入下列字型。图4：

7、切换回主场景1，删除舞台上的影片剪辑，实例将由代码生成。

8、打开库元件面板，右键单击影片剪辑，(CS3选链接、CS4选属性)给元件添加一个绑定类。类名  MenuItem 。图5：

9、选中第1帧，打开动作面板输入代码：

复制代码代码如下://The total number of menu items
const NUMBER_OF_ITEMS:uint = 20;
//This array will contain all the menu items
var menuItems:Array = new Array();
//Set the focal length
var focalLength:Number = 350;
//Set the vanishing point
var vanishingPointX:Number = stage.stageWidth / 2;
var vanishingPointY:Number = stage.stageHeight / 2;
//We calculate the angleSpeed in the ENTER_FRAME listener
var angleSpeed:Number = 0;
//Radius of the circle
var radius:Number = 128;
//Calculate the angle difference between the menu items (in radians)
var angleDifference:Number = Math.PI * (360 / NUMBER_OF_ITEMS) / 180;
//This loop creates and positions the carousel items
for (var i:uint = 0; i < NUMBER_OF_ITEMS; i++) {
//Create a new menu item
var menuItem:MenuItem = new MenuItem();
//Calculate the starting angle for the menu item
var startingAngle:Number = angleDifference * i;
//Set a currentAngle attribute for the menu item
menuItem.currentAngle = startingAngle;
//Position the menu item
menuItem.xpos3D = - radius * Math.cos(menuItem.currentAngle) * 0.5;
menuItem.ypos3D = radius * Math.sin(startingAngle);
menuItem.zpos3D = radius * Math.cos(startingAngle);
//Calculate the scale ratio for the menu item (the further the item -> the smaller the scale ratio)
var scaleRatio = focalLength/(focalLength + menuItem.zpos3D);
//Scale the menu item according to the scale ratio
menuItem.scaleX = menuItem.scaleY = scaleRatio;
//Position the menu item to the stage (from 3D to 2D coordinates)
menuItem.x = vanishingPointX + menuItem.xpos3D * scaleRatio;
menuItem.y = vanishingPointY + menuItem.ypos3D * scaleRatio;
//Assign an initial alpha
menuItem.alpha = 0.3;
//Add a text to the menu item
menuItem.menuItemText.text = Menu item + i;
//We don’t want the text field to catch mouse events
menuItem.mouseChildren = false;
//Assign MOUSE_OVER, MOUSE_OUT and CLICK listeners for the menu item
menuItem.addEventListener(MouseEvent.MOUSE_OVER, mouseOverItem);
menuItem.addEventListener(MouseEvent.MOUSE_OUT, mouseOutItem);
menuItem.addEventListener(MouseEvent.CLICK, itemClicked);
//Add the menu item to the menu items array
menuItems.push(menuItem);
//Add the menu item to the stage
addChild(menuItem);
}
//Add an ENTER_FRAME listener for the animation
addEventListener(Event.ENTER_FRAME, moveCarousel);
//This function is called in each frame
function moveCarousel(e:Event):void {
//Calculate the angle speed according to mouseY position
angleSpeed = (mouseY - stage.stageHeight / 2) * 0.0002;
//Loop through the menu items
for (var i:uint = 0; i < NUMBER_OF_ITEMS; i++) {
//Store the menu item to a local variable
var menuItem:MenuItem = (MenuItem)(menuItems[i]);
//Update the current angle of the item
menuItem.currentAngle += angleSpeed;
//Calculate a scale ratio
var scaleRatio = focalLength/(focalLength + menuItem.zpos3D);
//Scale the item according to the scale ratio
menuItem.scaleX=menuItem.scaleY=scaleRatio;
//Set new 3D coordinates
menuItem.xpos3D=- radius*Math.cos(menuItem.currentAngle)*0.5;
menuItem.ypos3D=radius*Math.sin(menuItem.currentAngle);
menuItem.zpos3D=radius*Math.cos(menuItem.currentAngle);
//Update the item’s coordinates.
menuItem.x=vanishingPointX+menuItem.xpos3D*scaleRatio;
menuItem.y=vanishingPointY+menuItem.ypos3D*scaleRatio;
}
//Call the function that sorts the items so they overlap each other correctly
sortZ();
}
//This function sorts the items so they overlap each other correctly
function sortZ():void {
//Sort the array so that the item which has the highest
//z position (= furthest away) is first in the array
menuItems.sortOn(zpos3D, Array.NUMERIC | Array.DESCENDING);
//Set new child indexes for the images
for (var i:uint = 0; i < NUMBER_OF_ITEMS; i++) {
setChildIndex(menuItems[i], i);
}
}
//This function is called when a mouse is over an item
function mouseOverItem(e:Event):void {
//Change the alpha to 1
e.target.alpha=1;
}
//This function is called when a mouse is out of an item
function mouseOutItem(e:Event):void {
//Change the alpha to 1
e.target.alpha=0.3;
}
//This function is called when an item is clicked
function itemClicked(e:Event):void {
trace(Item clicked! Add your own logic here.);
}