flex中Away3D更复杂的例子（支持拖拽改变摄像头角度）

1，下面通过一个更复杂的样例，演示Away3D的使用

（1）舞台中央添加一个地板，地板上方放置一个方块。方块与地板间有一段距离。

（2）地板和方块使用不同的纹理皮肤。

（3）默认摄像头的角度是沿x轴倾斜15度。

（4）按住鼠标左键拖动视图可以改变摄像头的视角，鼠标滚轮可以改变摄像头远近距离。

（5）整个舞台随窗口大小改变，一直保持全屏。

（6）添加抗锯齿设置，使物体边缘更加平滑。 

2，效果图如下：

package{
    import flash.display.Sprite;
    import flash.display.StageAlign;
    import flash.display.StageScaleMode;
    import flash.events.Event;
    import flash.events.MouseEvent;
    import flash.geom.Vector3D;
     
    import away3d.containers.View3D;
    import away3d.controllers.HoverController;
    import away3d.entities.Mesh;
    import away3d.materials.TextureMaterial;
    import away3d.primitives.CubeGeometry;
    import away3d.utils.Cast;
     
    [SWF(frameRate="60", backgroundColor="#FFFFFF")]
    public class S3 extends Sprite {
         
        private  var _view3D:View3D;
        private var cameraController:HoverController;//360全景展示相机控制器
         
        //物体 图片（用作方块 的纹理 ）
        [Embed(source="assets/snow_diffuse.png")]
        private var blockClass:Class;
         
        //地板图片（用作地板的纹理 ）
        [Embed(source="assets/road.jpg")]
        private var floorClass:Class;
         
        //物体材质
        private var blockMaterial:TextureMaterial;
         
        //地板材质
        private var floorMaterial:TextureMaterial;
         
        private var lastPanAngle:Number;
        private var lastTiltAngle:Number;
        private var lastMouseX:Number;
        private var lastMouseY:Number;
        private var move:Boolean;
         
        public function S3() {
            initEngine();
            initMaterials();
            initObjects();
            initListeners();
        }
         
        /**
         * 初始化引擎
         */
        private function initEngine():void
        {
            stage.scaleMode = StageScaleMode.NO_SCALE;
            stage.align = StageAlign.TOP_LEFT;
             
            // 创建一个视口
            _view3D = new View3D();
            _view3D.antiAlias = 4; //设置抗锯齿级别
             
            //初始化摄像头
            cameraController = new HoverController(_view3D.camera);
            /*cameraController.distance = 1000;
            cameraController.minTiltAngle = 0;
            cameraController.maxTiltAngle = 90;
            cameraController.panAngle = 45;*/
            cameraController.tiltAngle = 15;
             
            addChild(_view3D);
        }
         
        /**
         * 初始化材质
         */
        private function initMaterials():void
        {
            //地板的纹理
            floorMaterial = new TextureMaterial(Cast.bitmapTexture(floorClass));
            //方块 的纹理
            blockMaterial = new TextureMaterial(Cast.bitmapTexture(blockClass));
        }
         
        /**
         * 初始化物体
         */
        private function initObjects():void
        {
            // 在三维舞台中创建一个方块（地板 ）
            var cube1:Mesh = new Mesh(new CubeGeometry(700, 20, 500), floorMaterial);
            _view3D.scene.addChild(cube1);
             
            // 在三维舞台中创建一个方块（地板上的 方块 ）
            var cube2:Mesh = new Mesh(new CubeGeometry(200, 70, 200), blockMaterial);
            cube2.position = new Vector3D(0,100,0);
            _view3D.scene.addChild(cube2);
        }
         
        /**
         * 初始化监听
         */
        private function initListeners():void
        {
            addEventListener(Event.ENTER_FRAME, _onEnterFrame);
            //鼠标事件监听
            stage.addEventListener(MouseEvent.MOUSE_DOWN, onMouseDown);
            stage.addEventListener(MouseEvent.MOUSE_UP, onMouseUp);
            stage.addEventListener(MouseEvent.MOUSE_WHEEL,onWheel);
            stage.addEventListener(Event.RESIZE, onResize);
            onResize();
        }
         
        /**
         * 渲染视图
         */
        private function _onEnterFrame(e:Event):void
        {
             
            //移动视角
            if (move) {
                cameraController.panAngle = 0.3 * (stage.mouseX - lastMouseX) + lastPanAngle;
                cameraController.tiltAngle = 0.3 * (stage.mouseY - lastMouseY) + lastTiltAngle;
            }
            //渲染视图
            _view3D.render();
        }
         
        /**
         * 使用舞台大小一直全屏
         */
        private function onResize(event:Event = null):void
        {
            _view3D.width = stage.stageWidth;
            _view3D.height = stage.stageHeight;
        }
         
        /**
         * 鼠标滚轮事件
         */
        private function onWheel(e:MouseEvent):void
        {
            if(e.delta > 0){
                if(cameraController.distance < 1000)
                    cameraController.distance += 100;
            }else{
                if(cameraController.distance > 600)
                    cameraController.distance -= 100;
            }
        }
         
        /**
         * 鼠标按下事件
         */
        private function onMouseDown(event:MouseEvent):void
        {
            lastPanAngle = cameraController.panAngle;
            lastTiltAngle = cameraController.tiltAngle;
            lastMouseX = stage.mouseX;
            lastMouseY = stage.mouseY;
            move = true;
        }
         
        /**
         * 鼠标弹起事件
         */
        private function onMouseUp(event:MouseEvent):void
        {
            move = false;
        }
    }
}