OSG中擷取視點的全局座標

OSG中擷取視點的全局座標：

（1）osg::Vec3 vPosEye, vCenter, vUp;

     cameraMaster->getViewMatrixAsLookAt( vPosEye, vCenter, vUp);//擷取全局座標系下的視點值

（2）//主相機

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

 

           osg::Matrix _inverseMV;

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

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

/*擷取全局座標系下的視點座標：全局座標系中某點Pworld在視點座標系中為Pview，則Pview= Pworld * MV。則Pworld=Pview * MV逆，則視點座標系下的視點（0,0,0）在全局座標系下為：ptEye=（0,0,0）* MV逆。*/