// 得到逆矩阵，标准接口，控制场景
osg::Matrixd CameraController::getInverseMatrix(void) const
{
    std::cout << "----getInverseMatrix " << std::endl;

    osg::Matrixd matObj;
    matObj.makeRotate(m_vRotation._v[0], osg::Vec3(1.0f, 0.0f, 0.0f),
        m_vRotation._v[1], osg::Vec3(0.0f, 1.0f, 0.0f),
        m_vRotation._v[2], osg::Vec3(0.0f, 0.0f, 1.0f)
        );
    return osg::Matrixd::inverse(matObj * osg::Matrixd::translate(m_vPosition));
}