基于Away3D实现全景的相机控制器。

   最近研究打算做个全景的Demo，发现Away3D本身的天空盒跟全景属于两种完全不同东西。最后只能基于HoverController来扩展（原因是HoverController能提供的距离控制，类似拉近拉远的效果）等不够好用。下面直接贴出扩展的代码，命名RotateController。

   其实也就是在HoverController的基础上添加了对distance的距离判断，添加了对负值的显示控制..

package away3d.controllers

{

    import away3d.core.math.MathConsts;

    import away3d.core.render.PositionRenderer;

    import away3d.entities.Entity;

    

    import flash.geom.Matrix3D;

    import flash.geom.Vector3D;

    

    public class RotateController extends ControllerBase

    {

        private var _distance:Number = 100;

        

        private var _panAngle:Number = 0;

        

        private var _tiltAngle:Number = 0;

        

        private var _currentTiltAngle:Number = 0;

        

        private var _currentPanAngle:Number = 0;

        

        public function RotateController(targetObject:Entity=null)

        {

            super(targetObject);

        }

        

        override public function update(interpolate:Boolean=false):void

        {

            if (_invalid) {

                _invalid = false;

                

                if (_panAngle < 0) {

                    _currentPanAngle += _panAngle%360 + 360 - _panAngle;

                    _panAngle = _panAngle%360 + 360;

                } else {

                    _currentPanAngle += _panAngle%360 - _panAngle;

                    _panAngle = _panAngle%360;

                }

                

                while (_panAngle - _currentPanAngle < -180)

                    _currentPanAngle -= 360;

                

                while (_panAngle - _currentPanAngle > 180)

                    _currentPanAngle += 360;

                

                _currentPanAngle = _panAngle;

                _currentTiltAngle = _tiltAngle;

                

                

                if(targetObject)

                {

                    var tempMatrix3d:Matrix3D = targetObject.transform;

                    tempMatrix3d.identity();

                    

                    tempMatrix3d.appendRotation(_currentTiltAngle, Vector3D.X_AXIS);

                    tempMatrix3d.appendRotation(_currentPanAngle, Vector3D.Y_AXIS);

                    

                    var pos:Vector3D = new Vector3D;

                    pos.x = distance*Math.sin(_currentPanAngle*MathConsts.DEGREES_TO_RADIANS)*Math.cos(_currentTiltAngle*MathConsts.DEGREES_TO_RADIANS);

                    pos.z = distance*Math.cos(_currentPanAngle*MathConsts.DEGREES_TO_RADIANS)*Math.cos(_currentTiltAngle*MathConsts.DEGREES_TO_RADIANS);

                    pos.y = distance*Math.sin(_currentTiltAngle*MathConsts.DEGREES_TO_RADIANS);

                    

                    tempMatrix3d.appendTranslation(pos.x, -pos.y, pos.z);

                    

                    targetObject.transform = tempMatrix3d;

                    

                }

            }

        }



        public function get distance():Number

        {

            return _distance;

        }



        public function set distance(value:Number):void

        {

            _distance = value;

            _invalid = true;

            notifyUpdate();

        }



        public function get panAngle():Number

        {

            return _panAngle;

        }



        public function set panAngle(value:Number):void

        {

            _panAngle = value;

            _invalid = true;

            notifyUpdate();

        }



        public function get tiltAngle():Number

        {

            return _tiltAngle;

        }



        public function set tiltAngle(value:Number):void

        {

            _tiltAngle = Math.max(-90, Math.min(90, value));

            _invalid = true;

            notifyUpdate();

        }





        private var _invalid:Boolean = false;

    }

}