OSG中獲取視點的世界座標:
(1)osg::Vec3 vPosEye, vCenter, vUp;
cameraMaster->getViewMatrixAsLookAt( vPosEye, vCenter, vUp);//獲取世界座標系下的視點值
(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;
/*獲取世界座標系下的視點座標:世界座標系中某點Pworld在視點座標系中爲Pview,則Pview= Pworld * MV。則Pworld=Pview * MV逆,則視點座標系下的視點(0,0,0)在世界座標系下爲:ptEye=(0,0,0)* MV逆。*/