Before revision:  Our method is to enforce feature points lie on the same edge or plane by minimizing the eigenvalue of the covariance matrix.
After revision:  Our method is to enforce feature points lie on the same edge or plane . Unlike the visual SLAM (and prior plane adjustment method in lidar SLAM) where the feature has to be co-determined along with the pose, we show that the feature can be analytically solved and removed from the BA, the resultant BA is only dependent on the scan poses. This greatly reduces the optimization scale and allows large-scale dense plane and edge features to be used.