3d树实例

package com.ddd
{
    import flash.display.Sprite;

    public class Tree extends Sprite
    {
        public var xpos:Number=0;
        public var ypos:Number=0;
        public var zpos:Number=0;

        public function Tree()
        {
            init();
        }

        public function init():void
        {
            graphics.lineStyle(0, 0xffffff);
            graphics.lineTo(0, -140 - Math.random() * 20);
            graphics.moveTo(0, -30 - Math.random() * 30);
            graphics.lineTo(Math.random() * 80 - 40, -100 - Math.random() * 40);
            graphics.moveTo(0, -60 - Math.random() * 40);
            graphics.lineTo(Math.random() * 60 - 30, -110 - Math.random() * 20);
        }
    }
}

package com.ddd
{
    import flash.display.Sprite;
    import flash.display.StageScaleMode;
    import flash.events.Event;
    import flash.events.KeyboardEvent;
    import flash.ui.Keyboard;

    [SWF(backgroundColor=0x000000)]
    public class Trees extends Sprite
    {
        private var trees:Array=[];
        private var num:int=100;
        private var fl:Number=250;

        private var vpX:Number=stage.stageWidth / 2;
        private var vpY:Number=stage.stageHeight / 2;

        private var float:Number=50;
        private var fir:Number=.98;
        private var vz:Number=0;

        public function Trees()
        {
            super();
            stage.scaleMode=StageScaleMode.NO_SCALE;
            init();
        }

        private function init():void
        {
            var tree:Tree;
            for (var i:int=0; i < num; i++)
            {
                tree=new Tree;

                trees.push(tree);

                tree.xpos=Math.random() * 2000 - 1000;
                tree.ypos=float;
                tree.zpos=Math.random() * 1000;

                this.addChild(tree);
            }

            stage.addEventListener(KeyboardEvent.KEY_DOWN, onKeyDown)

            this.addEventListener(Event.ENTER_FRAME, onEnterFrame)
        }

        private function onEnterFrame(e:Event):void
        {
            for (var i:int=0; i < num; i++)
            {
                var tree:Tree=trees[i];
                move(tree);
            }

            vz*=fir;

            sortZ();
        }

        private function move(tree:Tree):void
        {
//            tree.vy+=g;
//
//            tree.xpos+=tree.vx;
//            tree.ypos+=tree.vy;
            tree.zpos+=vz;

//            if (tree.ypos > float)
//            {
//                tree.ypos=float;
//                tree.vy*=bounce;
//            }

            if (tree.zpos < -fl)
            {
                tree.zpos+=10000;
            }

            if (tree.zpos > 10000 - fl)
            {
                tree.zpos-=10000;
            }

            var scale:Number=fl / (fl + tree.zpos);

            tree.scaleX=tree.scaleY=scale;

            tree.x=vpX + tree.xpos * scale;
            tree.y=vpY + tree.ypos * scale;
        }

        private function sortZ():void
        {
            trees.sortOn("zpos", Array.DESCENDING | Array.NUMERIC);

            for (var i:int=0; i < num; i++)
            {
                setChildIndex(trees[i], i);
            }
        }

        private function onKeyDown(e:KeyboardEvent):void
        {
            if (e.keyCode == Keyboard.DOWN)
            {
                vz+=1;
            }
            else if (e.keyCode == Keyboard.UP)
            {
                vz-=1;
            }


        }

    }
}

package com.ddd
{
    import flash.display.Sprite;
    import flash.events.Event;
    import flash.events.KeyboardEvent;
    import flash.ui.Keyboard;

    [SWF(backgroundColor="0x0")]
    public class Trees2 extends Sprite
    {
        private var trees:Array=[];
        private var fl:Number=250;
        private var num:int=100;
        private var vpx:Number=stage.stageWidth / 2;
        private var vpy:Number=stage.stageHeight / 2;

        private var ax:Number=0;
        private var ay:Number=0;
        private var az:Number=0;

        private var vx:Number=0;
        private var vy:Number=0;
        private var vz:Number=0;

        private var float:Number=50;
        private var fir:Number=.98;
        private var g:Number=.3;

        public function Trees2()
        {
            super();
            init();
        }

        private function init():void
        {
            for (var i:int=0; i < num; i++)
            {
                var tree:Tree=new Tree;

                this.addChild(tree);

                trees.push(tree);

                tree.xpos=Math.random() * 2000 - 1000;
                tree.ypos=float;
                tree.zpos=Math.random() * 10000;
            }

            stage.addEventListener(KeyboardEvent.KEY_DOWN, onKeyDown);
            stage.addEventListener(KeyboardEvent.KEY_UP, onKeyUp);

            this.addEventListener(Event.ENTER_FRAME, onEnterFrame)
        }

        private function onEnterFrame(e:Event):void
        {
            vx+=ax;
            vy+=ay;
            vz+=az;

            vy-=g;

            for (var i:int=0; i < num; i++)
            {
                var tree:Tree=trees[i];
                move(tree);
            }

            vx*=fir;
            vy*=fir;
            vz*=fir;
        }

        private function sortZ():void
        {
            trees.sortOn("zpos", Array.DESCENDING | Array.NUMERIC);

            for (var i:int=0; i < num; i++)
            {
                var tree:Tree=trees[i];
                this.setChildIndex(tree, i);
            }
        }

        private function move(tree:Tree):void
        {
            tree.xpos+=vx;
            tree.ypos+=vy;
            tree.zpos+=vz;

            if (tree.ypos < float)
            {
                tree.ypos=float;
            }

            if (tree.zpos < -fl)
            {
                tree.zpos+=10000;
            }

            if (tree.zpos > 10000 - fl)
            {
                tree.zpos-=10000;
            }

            var scale:Number=fl / (fl + tree.zpos);

            tree.x=vpx + tree.xpos * scale;
            tree.y=vpy + tree.ypos * scale;
            tree.alpha=scale;
        }

        private function onKeyDown(e:KeyboardEvent):void
        {
            switch (e.keyCode)
            {
                case Keyboard.DOWN:
                    ay=1;
                    break;
                case Keyboard.UP:
                    ay=-1;
                    break;
                case Keyboard.LEFT:
                    ax=-1;
                    break;
                case Keyboard.RIGHT:
                    ax=1;
                    break;
                case Keyboard.SPACE:
                    az=1;
                    break;
            }
        }

        private function onKeyUp(e:KeyboardEvent):void
        {
            switch (e.keyCode)
            {
                case Keyboard.DOWN:
                    az=0
                    break;
                case Keyboard.RIGHT:
                    ax=0
                    break;
                case Keyboard.SPACE:
                    ay=0
                    break;
            }

        }

    }
}