flex Away3D 使用背景透明的贴图的教程

www.111cn.net 更新:2015-12-01 编辑:angel 来源:转载
Away3D 使用背景透明的贴图效果不能直接使用图片而需要通过图片与代码结合才可以实现了,我们下文就一起来看一个例子,希望对大家会带来帮助.

有时需要在舞台中添加一些背景透明的图片贴图,比如一些标志什么的。

这个就需要设置纹理材质的透明度(alpha 和 alphaThreshold),最后再使用 PlaneGeometry 平面类型的 Mesh 即可。 
 

比如,这里有一张背景透明的图片:


原文:Away3D - 使用背景透明的贴图
 

 

把它添加到视图中,效果图如下: 


原文:Away3D - 使用背景透明的贴图
   
原文:Away3D - 使用背景透明的贴图


package{
    import flash.display.Sprite;
    import flash.display.StageAlign;
    import flash.display.StageScaleMode;
    import flash.events.Event;
    import flash.events.MouseEvent;
     
    import away3d.containers.View3D;
    import away3d.controllers.HoverController;
    import away3d.entities.Mesh;
    import away3d.materials.TextureMaterial;
    import away3d.primitives.CubeGeometry;
    import away3d.primitives.PlaneGeometry;
    import away3d.utils.Cast;
     
    [SWF(frameRate="60", backgroundColor="#FFFFFF")]
    public class S5 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/logo_f10.png")]
        private var logoClass:Class;
         
        //地板图片(用作地板的纹理 )
        [Embed(source="assets/road.jpg")]
        private var floorClass:Class;
         
        //logo材质
        private var logoMaterial:TextureMaterial;
         
        //地板材质
        private var floorMaterial:TextureMaterial;
         
        private var _lastX:Number = 0;
        private var _lastY:Number = 0;
         
        public function S5() {
            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));
             
            //logo的纹理
            logoMaterial = new TextureMaterial(Cast.bitmapTexture(logoClass));
            logoMaterial.alpha = 1
            logoMaterial.alphaThreshold=0.5 //图片背景透明
        }
         
        /**
         * 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(500, 20, 300), floorMaterial);
            _view3D.scene.addChild(cube1);
             
            // 在三维舞台中创建一个平面的logo           
            var logo:Mesh = new Mesh(new PlaneGeometry(128, 128), logoMaterial);
            //(logo.geometry as PlaneGeometry).doubleSided = true; //双面 贴图
            logo.y = 100;
            logo.rotationX = 90;
            logo.rotationZ = 180;
            _view3D.scene.addChild(logo);
        }
         
        /**
         * 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
        {
            //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
        {
            _view3D.stage.addEventListener(MouseEvent.MOUSE_MOVE, mouseMoveHandler);
            _lastX = _view3D.mouseX;
            _lastY = _view3D.mouseY;
        }
         
        /**
         * 鼠标弹起事件
         */
        private function onMouseUp(event:MouseEvent):void
        {
            _view3D.stage.removeEventListener(MouseEvent.MOUSE_MOVE, mouseMoveHandler);
        }
         
        /**
         * 鼠标移动事件
         */
        private function mouseMoveHandler(event:MouseEvent):void
        {
            //移动摄像机
            var dx:Number = _view3D.mouseX - _lastX;
            var dy:Number = _view3D.mouseY - _lastY;
             
            cameraController.panAngle += dx;
            cameraController.tiltAngle += dy;
             
            _lastX = _view3D.mouseX;
            _lastY = _view3D.mouseY;
        }
    }
}