OSG中获取视点的世界座标

OSG中获取视点的世界座标：

（1）osg::Vec3 vPosEye, vCenter, vUp;

     cameraMaster->getViewMatrixAsLookAt( vPosEye, vCenter, vUp);//获取世界座标系下的视点值

（2）//主相机

           osg::ref_ptr<osg::Camera> cameraMaster = viewer->getCamera();

 

           osg::Matrix _inverseMV;

           _inverseMV.invert( cameraMaster->getViewMatrix());

           osg::Vec3 ptEye= osg::Vec3(  0, 0, 0) * _inverseMV;

/*获取世界座标系下的视点座标：世界座标系中某点Pworld在视点座标系中为Pview，则Pview= Pworld * MV。则Pworld=Pview * MV逆，则视点座标系下的视点（0,0,0）在世界座标系下为：ptEye=（0,0,0）* MV逆。*/