LimHyungTae/ERASOR

When using LIO-SAM, should I save the keyframe's pose ?

llxClover opened this issue · 2 comments

I'm using LIO-SAM, I do not know which pose should save. keyframe's pose ? every frame(the lidar frames between two keyframes are discarded)?

Here's my code! Please just refer to this code since it's rather personalized such as de_msg/node.h. What you note is saveEachPosesAndDeskewedPcs function part.

#include "utility.h"
#include "lio_sam/cloud_info.h"
#include "lio_sam/save_map.h"
#include "de_msg/node.h"
#include <iomanip> // for std::setprecision()
//#include <pcl/common/transforms.h>

#include <gtsam/geometry/Rot3.h>
#include <gtsam/geometry/Pose3.h>
#include <gtsam/slam/PriorFactor.h>
#include <gtsam/slam/BetweenFactor.h>
#include <gtsam/navigation/GPSFactor.h>
#include <gtsam/navigation/ImuFactor.h>
#include <gtsam/navigation/CombinedImuFactor.h>
#include <gtsam/nonlinear/NonlinearFactorGraph.h>
#include <gtsam/nonlinear/LevenbergMarquardtOptimizer.h>
#include <gtsam/nonlinear/Marginals.h>
#include <gtsam/nonlinear/Values.h>
#include <gtsam/inference/Symbol.h>

#include <gtsam/nonlinear/ISAM2.h>

using namespace gtsam;

using symbol_shorthand::X; // Pose3 (x,y,z,r,p,y)
using symbol_shorthand::V; // Vel   (xdot,ydot,zdot)
using symbol_shorthand::B; // Bias  (ax,ay,az,gx,gy,gz)
using symbol_shorthand::G; // GPS pose

/*
    * A point cloud type that has 6D pose info ([x,y,z,roll,pitch,yaw] intensity is time stamp)
    */
struct PointXYZIRPYT {
    PCL_ADD_POINT4D

    PCL_ADD_INTENSITY;                  // preferred way of adding a XYZ+padding
    float  roll;
    float  pitch;
    float  yaw;
    double time;

    EIGEN_MAKE_ALIGNED_OPERATOR_NEW   // make sure our new allocators are aligned
} EIGEN_ALIGN16;                    // enforce SSE padding for correct memory alignment

POINT_CLOUD_REGISTER_POINT_STRUCT (PointXYZIRPYT,
                                   (float, x, x)(float, y, y)
                                           (float, z, z)(float, intensity, intensity)
                                           (float, roll, roll)(float, pitch, pitch)(float, yaw, yaw)
                                           (double, time, time))

typedef PointXYZIRPYT PointTypePose;


class mapOptimization : public ParamServer {

public:
    EIGEN_MAKE_ALIGNED_OPERATOR_NEW

    // gtsam
    NonlinearFactorGraph gtSAMgraph;
    Values               initialEstimate;
    Values               optimizedEstimate;
    ISAM2                *isam;
    Values               isamCurrentEstimate;
    Eigen::MatrixXd      poseCovariance;

    ros::Publisher pubLaserCloudSurround;
    ros::Publisher pubDeskewLaserCloud;
    ros::Publisher pubLaserOdometryGlobal;
    ros::Publisher pubNode;
    ros::Publisher pubLaserOdometryIncremental;
    ros::Publisher pubKeyPoses;
    ros::Publisher pubPath;

    ros::Publisher pubHistoryKeyFrames;
    ros::Publisher pubIcpKeyFrames;
    ros::Publisher pubRecentKeyFrames;
    ros::Publisher pubRecentKeyFrame;
    ros::Publisher pubCloudRegisteredRaw;
    ros::Publisher pubLoopConstraintEdge;

    ros::Subscriber subCloud;
    ros::Subscriber subGPS;
    ros::Subscriber subLoop;

    ros::ServiceServer srvSaveMap;

    std::deque<nav_msgs::Odometry> gpsQueue;
    lio_sam::cloud_info            cloudInfo;

    PointTypePose poseWrtInit;

    vector<pcl::PointCloud<PointType>::Ptr> deskewCloudKeyFrames;
    vector<pcl::PointCloud<PointType>::Ptr> cornerCloudKeyFrames;
    vector<pcl::PointCloud<PointType>::Ptr> surfCloudKeyFrames;
    vector<double>                          timestamps;

    pcl::PointCloud<PointType>::Ptr     cloudKeyPoses3D;
    pcl::PointCloud<PointTypePose>::Ptr cloudKeyPoses6D;
    pcl::PointCloud<PointType>::Ptr     copy_cloudKeyPoses3D;
    pcl::PointCloud<PointTypePose>::Ptr copy_cloudKeyPoses6D;

    pcl::PointCloud<PointType>::Ptr laserCloudDeskewLast; // Deskew
    pcl::PointCloud<PointType>::Ptr laserCloudCornerLast; // corner feature set from odoOptimization
    pcl::PointCloud<PointType>::Ptr laserCloudSurfLast; // surf feature set from odoOptimization

    pcl::PointCloud<PointType>::Ptr laserCloudDeskewLastDS; // downsampled raw point cloud
    pcl::PointCloud<PointType>::Ptr laserCloudCornerLastDS; // downsampled corner featuer set from odoOptimization
    pcl::PointCloud<PointType>::Ptr laserCloudSurfLastDS; // downsampled surf featuer set from odoOptimization

    pcl::PointCloud<PointType>::Ptr laserCloudOri;
    pcl::PointCloud<PointType>::Ptr coeffSel;

    std::vector<PointType> laserCloudOriCornerVec; // corner point holder for parallel computation
    std::vector<PointType> coeffSelCornerVec;
    std::vector<bool>      laserCloudOriCornerFlag;
    std::vector<PointType> laserCloudOriSurfVec; // surf point holder for parallel computation
    std::vector<PointType> coeffSelSurfVec;
    std::vector<bool>      laserCloudOriSurfFlag;

    map<int, pair<pcl::PointCloud<PointType>, pcl::PointCloud<PointType>>> laserCloudMapContainer;
    pcl::PointCloud<PointType>::Ptr                                        laserCloudCornerFromMap;
    pcl::PointCloud<PointType>::Ptr                                        laserCloudSurfFromMap;
    pcl::PointCloud<PointType>::Ptr                                        laserCloudCornerFromMapDS;
    pcl::PointCloud<PointType>::Ptr                                        laserCloudSurfFromMapDS;

    pcl::KdTreeFLANN<PointType>::Ptr kdtreeCornerFromMap;
    pcl::KdTreeFLANN<PointType>::Ptr kdtreeSurfFromMap;

    pcl::KdTreeFLANN<PointType>::Ptr kdtreeSurroundingKeyPoses;
    pcl::KdTreeFLANN<PointType>::Ptr kdtreeHistoryKeyPoses;

    pcl::VoxelGrid<PointType> downSizeFilterDeskew;
    pcl::VoxelGrid<PointType> downSizeFilterCorner;
    pcl::VoxelGrid<PointType> downSizeFilterSurf;
    pcl::VoxelGrid<PointType> downSizeFilterICP;
    pcl::VoxelGrid<PointType> downSizeFilterSurroundingKeyPoses; // for surrounding key poses of scan-to-map optimization

    ros::Time timeLaserInfoStamp;
    double    timeLaserInfoCur;
    double    timeLaserInfoCurToSave;

    float transformTobeMapped[6];

    std::mutex mtx;
    std::mutex mtxLoopInfo;

    bool    isDegenerate = false;
    cv::Mat matP;

    int laserCloudCornerFromMapDSNum = 0;
    int laserCloudSurfFromMapDSNum   = 0;
    int laserCloudCornerLastDSNum    = 0;
    int laserCloudSurfLastDSNum      = 0;

    bool                                            aLoopIsClosed = false;
    map<int, int>                                   loopIndexContainer; // from new to old
    vector<pair<int, int>>                          loopIndexQueue;
    vector<gtsam::Pose3>                            loopPoseQueue;
    vector<gtsam::noiseModel::Diagonal::shared_ptr> loopNoiseQueue;
    deque<std_msgs::Float64MultiArray>              loopInfoVec;

    nav_msgs::Path globalPath;

    Eigen::Affine3f transPointAssociateToMap;
    Eigen::Affine3f incrementalOdometryAffineFront;
    Eigen::Affine3f incrementalOdometryAffineBack;


    mapOptimization() {
        ISAM2Params parameters;
        parameters.relinearizeThreshold = 0.1;
        parameters.relinearizeSkip      = 1;
        isam = new ISAM2(parameters);

        pubKeyPoses                 = nh.advertise<sensor_msgs::PointCloud2>("lio_sam/mapping/trajectory", 1);
        pubLaserCloudSurround       = nh.advertise<sensor_msgs::PointCloud2>("lio_sam/mapping/map_global", 1);
//        pubDeskewLaserCloud         = nh.advertise<sensor_msgs::PointCloud2>("lio_sam/mapping/deskew_local", 1);
        pubLaserOdometryGlobal      = nh.advertise<nav_msgs::Odometry>("lio_sam/mapping/odometry", 1);
        pubLaserOdometryIncremental = nh.advertise<nav_msgs::Odometry>("lio_sam/mapping/odometry_incremental", 1);
        pubPath                     = nh.advertise<nav_msgs::Path>("lio_sam/mapping/path", 1);

        pubNode                     = nh.advertise<de_msg::node>("lio_sam/mapping/node", 1);

        subCloud = nh.subscribe<lio_sam::cloud_info>("lio_sam/feature/cloud_info", 1, &mapOptimization::laserCloudInfoHandler, this,
                                                     ros::TransportHints().tcpNoDelay());
        subGPS   = nh.subscribe<nav_msgs::Odometry>(gpsTopic, 200, &mapOptimization::gpsHandler, this, ros::TransportHints().tcpNoDelay());
        subLoop  = nh.subscribe<std_msgs::Float64MultiArray>("lio_loop/loop_closure_detection", 1, &mapOptimization::loopInfoHandler, this,
                                                             ros::TransportHints().tcpNoDelay());

        srvSaveMap = nh.advertiseService("lio_sam/save_map", &mapOptimization::saveMapService, this);

        pubHistoryKeyFrames   = nh.advertise<sensor_msgs::PointCloud2>("lio_sam/mapping/icp_loop_closure_history_cloud", 1);
        pubIcpKeyFrames       = nh.advertise<sensor_msgs::PointCloud2>("lio_sam/mapping/icp_loop_closure_corrected_cloud", 1);
        pubLoopConstraintEdge = nh.advertise<visualization_msgs::MarkerArray>("/lio_sam/mapping/loop_closure_constraints", 1);

        pubRecentKeyFrames    = nh.advertise<sensor_msgs::PointCloud2>("lio_sam/mapping/map_local", 1);
        pubRecentKeyFrame     = nh.advertise<sensor_msgs::PointCloud2>("lio_sam/mapping/cloud_registered", 1);
        pubCloudRegisteredRaw = nh.advertise<sensor_msgs::PointCloud2>("lio_sam/mapping/cloud_registered_raw", 1);

        downSizeFilterDeskew.setLeafSize(0.05, 0.05, 0.05);

        downSizeFilterCorner.setLeafSize(mappingCornerLeafSize, mappingCornerLeafSize, mappingCornerLeafSize);
        downSizeFilterSurf.setLeafSize(mappingSurfLeafSize, mappingSurfLeafSize, mappingSurfLeafSize);
        downSizeFilterICP.setLeafSize(mappingSurfLeafSize, mappingSurfLeafSize, mappingSurfLeafSize);
        downSizeFilterSurroundingKeyPoses.setLeafSize(surroundingKeyframeDensity, surroundingKeyframeDensity,
                                                      surroundingKeyframeDensity); // for surrounding key poses of scan-to-map optimization

        allocateMemory();
    }

    void allocateMemory() {
        cloudKeyPoses3D.reset(new pcl::PointCloud<PointType>());
        cloudKeyPoses6D.reset(new pcl::PointCloud<PointTypePose>());
        copy_cloudKeyPoses3D.reset(new pcl::PointCloud<PointType>());
        copy_cloudKeyPoses6D.reset(new pcl::PointCloud<PointTypePose>());

        kdtreeSurroundingKeyPoses.reset(new pcl::KdTreeFLANN<PointType>());
        kdtreeHistoryKeyPoses.reset(new pcl::KdTreeFLANN<PointType>());

        // Deskew for static map building
        laserCloudDeskewLast.reset(new pcl::PointCloud<PointType>());
        laserCloudCornerLast.reset(new pcl::PointCloud<PointType>()); // corner feature set from odoOptimization
        laserCloudSurfLast.reset(new pcl::PointCloud<PointType>()); // surf feature set from odoOptimization

        laserCloudDeskewLastDS.reset(new pcl::PointCloud<PointType>());
        laserCloudCornerLastDS.reset(new pcl::PointCloud<PointType>()); // downsampled corner featuer set from odoOptimization
        laserCloudSurfLastDS.reset(new pcl::PointCloud<PointType>()); // downsampled surf featuer set from odoOptimization

        laserCloudOri.reset(new pcl::PointCloud<PointType>());
        coeffSel.reset(new pcl::PointCloud<PointType>());

        laserCloudOriCornerVec.resize(N_SCAN * Horizon_SCAN);
        coeffSelCornerVec.resize(N_SCAN * Horizon_SCAN);
        laserCloudOriCornerFlag.resize(N_SCAN * Horizon_SCAN);
        laserCloudOriSurfVec.resize(N_SCAN * Horizon_SCAN);
        coeffSelSurfVec.resize(N_SCAN * Horizon_SCAN);
        laserCloudOriSurfFlag.resize(N_SCAN * Horizon_SCAN);

        std::fill(laserCloudOriCornerFlag.begin(), laserCloudOriCornerFlag.end(), false);
        std::fill(laserCloudOriSurfFlag.begin(), laserCloudOriSurfFlag.end(), false);

        laserCloudCornerFromMap.reset(new pcl::PointCloud<PointType>());
        laserCloudSurfFromMap.reset(new pcl::PointCloud<PointType>());
        laserCloudCornerFromMapDS.reset(new pcl::PointCloud<PointType>());
        laserCloudSurfFromMapDS.reset(new pcl::PointCloud<PointType>());

        kdtreeCornerFromMap.reset(new pcl::KdTreeFLANN<PointType>());
        kdtreeSurfFromMap.reset(new pcl::KdTreeFLANN<PointType>());

        for (int i = 0; i < 6; ++i) {
            transformTobeMapped[i] = 0;
        }

        matP = cv::Mat(6, 6, CV_32F, cv::Scalar::all(0));
    }

    void laserCloudInfoHandler(const lio_sam::cloud_infoConstPtr &msgIn) {
        // extract time stamp
        timeLaserInfoStamp     = msgIn->header.stamp;
        timeLaserInfoCur       = msgIn->header.stamp.toSec();
        timeLaserInfoCurToSave = msgIn->header.stamp.toNSec();

        // extract info and feature cloud
        cloudInfo = *msgIn;
        pcl::fromROSMsg(msgIn->cloud_deskewed, *laserCloudDeskewLast);
        pcl::fromROSMsg(msgIn->cloud_corner, *laserCloudCornerLast);
        pcl::fromROSMsg(msgIn->cloud_surface, *laserCloudSurfLast);

        std::lock_guard<std::mutex> lock(mtx);

        static double timeLastProcessing = -1;
        if (timeLaserInfoCur - timeLastProcessing >= mappingProcessInterval) {
            timeLastProcessing = timeLaserInfoCur;

            updateInitialGuess();

            extractSurroundingKeyFrames();

            downsampleCurrentScan();

            scan2MapOptimization();

            saveKeyFramesAndFactor();

            correctPoses();

            publishOdometry();

            publishLastMileNode();

            publishFrames();
        }
    }

    void gpsHandler(const nav_msgs::Odometry::ConstPtr &gpsMsg) {
        gpsQueue.push_back(*gpsMsg);
    }

    void pointAssociateToMap(PointType const *const pi, PointType *const po) {
        po->x =
                transPointAssociateToMap(0, 0) * pi->x + transPointAssociateToMap(0, 1) * pi->y + transPointAssociateToMap(0, 2) * pi->z +
                transPointAssociateToMap(0, 3);
        po->y =
                transPointAssociateToMap(1, 0) * pi->x + transPointAssociateToMap(1, 1) * pi->y + transPointAssociateToMap(1, 2) * pi->z +
                transPointAssociateToMap(1, 3);
        po->z =
                transPointAssociateToMap(2, 0) * pi->x + transPointAssociateToMap(2, 1) * pi->y + transPointAssociateToMap(2, 2) * pi->z +
                transPointAssociateToMap(2, 3);
        po->intensity = pi->intensity;
    }

    pcl::PointCloud<PointType>::Ptr transformPointCloud(pcl::PointCloud<PointType>::Ptr cloudIn, PointTypePose *transformIn) {
        pcl::PointCloud<PointType>::Ptr cloudOut(new pcl::PointCloud<PointType>());

        int cloudSize = cloudIn->size();
        cloudOut->resize(cloudSize);

        Eigen::Affine3f transCur = pcl::getTransformation(transformIn->x, transformIn->y, transformIn->z, transformIn->roll,
                                                          transformIn->pitch, transformIn->yaw);

#pragma omp parallel for num_threads(numberOfCores)
        for (int i = 0; i < cloudSize; ++i) {
            const auto &pointFrom = cloudIn->points[i];
            cloudOut->points[i].x =
                    transCur(0, 0) * pointFrom.x + transCur(0, 1) * pointFrom.y + transCur(0, 2) * pointFrom.z + transCur(0, 3);
            cloudOut->points[i].y =
                    transCur(1, 0) * pointFrom.x + transCur(1, 1) * pointFrom.y + transCur(1, 2) * pointFrom.z + transCur(1, 3);
            cloudOut->points[i].z =
                    transCur(2, 0) * pointFrom.x + transCur(2, 1) * pointFrom.y + transCur(2, 2) * pointFrom.z + transCur(2, 3);
            cloudOut->points[i].intensity = pointFrom.intensity;
        }
        return cloudOut;
    }

    gtsam::Pose3 pclPointTogtsamPose3(PointTypePose thisPoint) {
        return gtsam::Pose3(gtsam::Rot3::RzRyRx(double(thisPoint.roll), double(thisPoint.pitch), double(thisPoint.yaw)),
                            gtsam::Point3(double(thisPoint.x), double(thisPoint.y), double(thisPoint.z)));
    }

    gtsam::Pose3 trans2gtsamPose(float transformIn[]) {
        return gtsam::Pose3(gtsam::Rot3::RzRyRx(transformIn[0], transformIn[1], transformIn[2]),
                            gtsam::Point3(transformIn[3], transformIn[4], transformIn[5]));
    }

    Eigen::Affine3f pclPointToAffine3f(PointTypePose thisPoint) {
        return pcl::getTransformation(thisPoint.x, thisPoint.y, thisPoint.z, thisPoint.roll, thisPoint.pitch, thisPoint.yaw);
    }

    Eigen::Affine3f trans2Affine3f(float transformIn[]) {
        return pcl::getTransformation(transformIn[3], transformIn[4], transformIn[5], transformIn[0], transformIn[1], transformIn[2]);
    }

    PointTypePose trans2PointTypePose(float transformIn[]) {
        PointTypePose thisPose6D;
        thisPose6D.x     = transformIn[3];
        thisPose6D.y     = transformIn[4];
        thisPose6D.z     = transformIn[5];
        thisPose6D.roll  = transformIn[0];
        thisPose6D.pitch = transformIn[1];
        thisPose6D.yaw   = transformIn[2];
        return thisPose6D;
    }


    bool saveMapService(lio_sam::save_mapRequest &req, lio_sam::save_mapResponse &res) {
        string saveMapDirectory;

        cout << "****************************************************" << endl;
        cout << "Saving map to pcd files ..." << endl;
        if (req.destination.empty()) saveMapDirectory = std::getenv("HOME") + savePCDDirectory;
        else saveMapDirectory = std::getenv("HOME") + req.destination;
        cout << "Save destination: " << saveMapDirectory << endl;
        // create directory and remove old files;
        int unused = system((std::string("exec rm -r ") + saveMapDirectory).c_str());
        unused                            = system((std::string("mkdir -p ") + saveMapDirectory).c_str());
        // save key frame transformations
        pcl::io::savePCDFileBinary(saveMapDirectory + "/trajectory.pcd", *cloudKeyPoses3D);
        pcl::io::savePCDFileBinary(saveMapDirectory + "/transformations.pcd", *cloudKeyPoses6D);
        // extract global point cloud map
        pcl::PointCloud<PointType>::Ptr globalCornerCloud(new pcl::PointCloud<PointType>());
        pcl::PointCloud<PointType>::Ptr globalCornerCloudDS(new pcl::PointCloud<PointType>());
        pcl::PointCloud<PointType>::Ptr globalSurfCloud(new pcl::PointCloud<PointType>());
        pcl::PointCloud<PointType>::Ptr globalSurfCloudDS(new pcl::PointCloud<PointType>());
        pcl::PointCloud<PointType>::Ptr globalMapCloud(new pcl::PointCloud<PointType>());
        for (int                        i = 0; i < (int) cloudKeyPoses3D->size(); i++) {
            auto  wrtInit = pclPointToAffine3f(cloudKeyPoses6D->points[0]).inverse() * pclPointToAffine3f(cloudKeyPoses6D->points[i]);
            float x, y, z, roll, pitch, yaw;
            pcl::getTranslationAndEulerAngles(wrtInit, x, y, z, roll, pitch, yaw);

            poseWrtInit.x     = x;
            poseWrtInit.y     = y;
            poseWrtInit.z     = z;
            poseWrtInit.roll  = roll;
            poseWrtInit.pitch = pitch;
            poseWrtInit.yaw   = yaw;

            *globalCornerCloud += *transformPointCloud(cornerCloudKeyFrames[i], &poseWrtInit);
            *globalSurfCloud += *transformPointCloud(surfCloudKeyFrames[i], &poseWrtInit);
            cout << "\r" << std::flush << "Processing feature cloud " << i << " of " << cloudKeyPoses6D->size() << " ...";
        }

        Eigen::Matrix4f lidar2box;
        setLiDAR2box(lidar2box, "top");

        saveEachPosesAndDeskewedPcs(saveMapDirectory, lidar2box);

        if (req.resolution != 0) {
            cout << "\n\nSave resolution: " << req.resolution << endl;

            // down-sample and save corner cloud
            downSizeFilterCorner.setInputCloud(globalCornerCloud);
            downSizeFilterCorner.setLeafSize(req.resolution, req.resolution, req.resolution);
            downSizeFilterCorner.filter(*globalCornerCloudDS);
            pcl::io::savePCDFileBinary(saveMapDirectory + "/CornerMap.pcd", *globalCornerCloudDS);
            // down-sample and save surf cloud
            downSizeFilterSurf.setInputCloud(globalSurfCloud);
            downSizeFilterSurf.setLeafSize(req.resolution, req.resolution, req.resolution);
            downSizeFilterSurf.filter(*globalSurfCloudDS);
            pcl::io::savePCDFileBinary(saveMapDirectory + "/SurfMap.pcd", *globalSurfCloudDS);
        } else {
            // save corner cloud
            pcl::io::savePCDFileBinary(saveMapDirectory + "/CornerMap.pcd", *globalCornerCloud);
            // save surf cloud
            pcl::io::savePCDFileBinary(saveMapDirectory + "/SurfMap.pcd", *globalSurfCloud);
        }

        // save global point cloud map
        *globalMapCloud += *globalCornerCloud;
        *globalMapCloud += *globalSurfCloud;

//        pcl::PointCloud<PointType>::Ptr globalMapWrtBox(new pcl::PointCloud<PointType>());
//        pcl::transformPointCloud(*globalMapCloud, *globalMapWrtBox, lidar2box.inverse());
        int ret = pcl::io::savePCDFileBinary(saveMapDirectory + "/GlobalMap.pcd", *globalMapCloud);
        res.success = ret == 0;

        downSizeFilterCorner.setLeafSize(mappingCornerLeafSize, mappingCornerLeafSize, mappingCornerLeafSize);
        downSizeFilterSurf.setLeafSize(mappingSurfLeafSize, mappingSurfLeafSize, mappingSurfLeafSize);

        cout << "****************************************************" << endl;
        cout << "Saving map to pcd files completed\n" << endl;

        return true;
    }

    void visualizeGlobalMapThread() {
        ros::Rate rate(0.2);
        while (ros::ok()) {
            rate.sleep();
            publishGlobalMap();
        }

        if (savePCD == false)
            return;

        lio_sam::save_mapRequest  req;
        lio_sam::save_mapResponse res;

        // if(!saveMapService(req, res)){
        //    cout << "Fail to save map" << endl;
        //}
    }

    void publishGlobalMap() {
        if (pubLaserCloudSurround.getNumSubscribers() == 0)
            return;

        if (cloudKeyPoses3D->points.empty() == true)
            return;

        pcl::KdTreeFLANN<PointType>::Ptr kdtreeGlobalMap(new pcl::KdTreeFLANN<PointType>());;
        pcl::PointCloud<PointType>::Ptr globalMapKeyPoses(new pcl::PointCloud<PointType>());
        pcl::PointCloud<PointType>::Ptr globalMapKeyPosesDS(new pcl::PointCloud<PointType>());
        pcl::PointCloud<PointType>::Ptr globalMapKeyFrames(new pcl::PointCloud<PointType>());
        pcl::PointCloud<PointType>::Ptr globalMapKeyFramesDS(new pcl::PointCloud<PointType>());

        // kd-tree to find near key frames to visualize
        std::vector<int>   pointSearchIndGlobalMap;
        std::vector<float> pointSearchSqDisGlobalMap;
        // search near key frames to visualize
        mtx.lock();
        kdtreeGlobalMap->setInputCloud(cloudKeyPoses3D);
        kdtreeGlobalMap->radiusSearch(cloudKeyPoses3D->back(), globalMapVisualizationSearchRadius, pointSearchIndGlobalMap,
                                      pointSearchSqDisGlobalMap, 0);
        mtx.unlock();

        for (int                  i = 0; i < (int) pointSearchIndGlobalMap.size(); ++i)
            globalMapKeyPoses->push_back(cloudKeyPoses3D->points[pointSearchIndGlobalMap[i]]);
        // downsample near selected key frames
        pcl::VoxelGrid<PointType> downSizeFilterGlobalMapKeyPoses; // for global map visualization
        downSizeFilterGlobalMapKeyPoses.setLeafSize(globalMapVisualizationPoseDensity, globalMapVisualizationPoseDensity,
                                                    globalMapVisualizationPoseDensity); // for global map visualization
        downSizeFilterGlobalMapKeyPoses.setInputCloud(globalMapKeyPoses);
        downSizeFilterGlobalMapKeyPoses.filter(*globalMapKeyPosesDS);
        for (auto &pt : globalMapKeyPosesDS->points) {
            kdtreeGlobalMap->nearestKSearch(pt, 1, pointSearchIndGlobalMap, pointSearchSqDisGlobalMap);
            pt.intensity = cloudKeyPoses3D->points[pointSearchIndGlobalMap[0]].intensity;
        }

        // extract visualized and downsampled key frames
        for (int                  i = 0; i < (int) globalMapKeyPosesDS->size(); ++i) {
            if (pointDistance(globalMapKeyPosesDS->points[i], cloudKeyPoses3D->back()) > globalMapVisualizationSearchRadius)
                continue;
            int thisKeyInd = (int) globalMapKeyPosesDS->points[i].intensity;
            *globalMapKeyFrames += *transformPointCloud(cornerCloudKeyFrames[thisKeyInd], &cloudKeyPoses6D->points[thisKeyInd]);
            *globalMapKeyFrames += *transformPointCloud(surfCloudKeyFrames[thisKeyInd], &cloudKeyPoses6D->points[thisKeyInd]);
        }
        // downsample visualized points
        pcl::VoxelGrid<PointType> downSizeFilterGlobalMapKeyFrames; // for global map visualization
        downSizeFilterGlobalMapKeyFrames.setLeafSize(globalMapVisualizationLeafSize, globalMapVisualizationLeafSize,
                                                     globalMapVisualizationLeafSize); // for global map visualization
        downSizeFilterGlobalMapKeyFrames.setInputCloud(globalMapKeyFrames);
        downSizeFilterGlobalMapKeyFrames.filter(*globalMapKeyFramesDS);
        publishCloud(&pubLaserCloudSurround, globalMapKeyFramesDS, timeLaserInfoStamp, odometryFrame);
    }


    void saveEachPosesAndDeskewedPcs(string &mapdir, const Eigen::Matrix4f &lidar2box) {
        string   filename = (boost::format("%s/poses_lio2box.csv") % mapdir).str();
        ofstream poses_txt(filename);

        poses_txt << "index, timestamp, x, y, z, qx, qy, qz, qw" << "\n";
        if (timestamps.size() != cloudKeyPoses6D->size()) {
            cout << timestamps.size() << " vs " << cloudKeyPoses6D->size() << endl;
            throw invalid_argument("[saveEachPoses] Sizes are not equal!!");
        }

        if (deskewCloudKeyFrames.size() != cloudKeyPoses6D->size()) {
            cout << deskewCloudKeyFrames.size() << " vs " << cloudKeyPoses6D->size() << endl;
            throw invalid_argument("[saveEachPoses] Deskew Cloud Sizes are not equal!!");
        }


        pcl::PointCloud<PointType>::Ptr globalMapWrtBox(new pcl::PointCloud<PointType>());
        pcl::PointCloud<PointType>::Ptr globalMapWrtBoxDS(new pcl::PointCloud<PointType>());

        for (int i = 0; i < (int) cloudKeyPoses6D->size(); i++) {
            auto  wrtInit = pclPointToAffine3f(cloudKeyPoses6D->points[0]).inverse() * pclPointToAffine3f(cloudKeyPoses6D->points[i]);
            float x, y, z, roll, pitch, yaw;
            pcl::getTranslationAndEulerAngles(wrtInit, x, y, z, roll, pitch, yaw);

            poseWrtInit.x     = x;
            poseWrtInit.y     = y;
            poseWrtInit.z     = z;
            poseWrtInit.roll  = roll;
            poseWrtInit.pitch = pitch;
            poseWrtInit.yaw   = yaw;


            const auto     &p = poseWrtInit;
            tf::Quaternion q;
            q.setRPY(p.roll, p.pitch, p.yaw);
            q.normalize();

//            poses_txt << i << ", " << timestamps[i] << ", " << p.x << ", " << p.y << ", " << p.z
//                      << ", "
//                      << q.getX() << ", " << q.getY() << ", " << q.getZ() << ", " << q.getW()
//                      << "\n";

            // Pose: sensor box
            Eigen::Matrix4f pose = Eigen::Matrix4f::Identity();
            pose(0, 3) = p.x;
            pose(1, 3) = p.y;
            pose(2, 3) = p.z;
            tf::Matrix3x3 rot;
            rot.setRotation(q);
            auto               rotation   = rotMat2EigenRot(rot);
            for (int           i          = 0; i < 3; ++i) {
                for (int j = 0; j < 3; ++j) {
                    pose(i, j) = rotation(i, j);
                }
            }
            Eigen::Matrix4f    poseWrtBox = pose * lidar2box;
            Eigen::Quaternionf q_tf(poseWrtBox.block<3, 3>(0, 0));
            std::cout << std::setprecision(18);
//            cout<< timestamps[i] <<endl;
            poses_txt << std::setprecision(18) << i << ", " << (timestamps[i]) << ", " << poseWrtBox(0, 3) << ", " << poseWrtBox(1, 3)
                      << ", " << poseWrtBox(2, 3)
                      << ", " << q_tf.x() << ", " << q_tf.y() << ", " << q_tf.z() << ", " << q_tf.w() << "\n";

            pcl::PointCloud<PointType>::Ptr deskewWrtBox(new pcl::PointCloud<PointType>());
            pcl::transformPointCloud(*deskewCloudKeyFrames[i], *deskewWrtBox, lidar2box.inverse());
            string output_name = (boost::format("%s/%06d.pcd") % mapdir % i).str();
            pcl::io::savePCDFileASCII(output_name, *deskewWrtBox);

            pcl::PointCloud<PointType>::Ptr deskewGlobal(new pcl::PointCloud<PointType>());
            pcl::transformPointCloud(*deskewWrtBox, *deskewGlobal, poseWrtBox);
            *globalMapWrtBox += *deskewGlobal;
        }
        downSizeFilterDeskew.setInputCloud(globalMapWrtBox);
        downSizeFilterDeskew.filter(*globalMapWrtBoxDS);

        string dense_name = (boost::format("%s/dense_global_map.pcd") % mapdir).str();
        pcl::io::savePCDFileASCII(dense_name, *globalMapWrtBoxDS);

        poses_txt.close();


    }

    Eigen::Matrix3f rotMat2EigenRot(const tf::Matrix3x3 &rotMat) {
        Eigen::Matrix3f eigenRotMat(3, 3);
        eigenRotMat(0, 0) = rotMat[0][0];
        eigenRotMat(0, 1) = rotMat[0][1];
        eigenRotMat(0, 2) = rotMat[0][2];
        eigenRotMat(1, 0) = rotMat[1][0];
        eigenRotMat(1, 1) = rotMat[1][1];
        eigenRotMat(1, 2) = rotMat[1][2];
        eigenRotMat(2, 0) = rotMat[2][0];
        eigenRotMat(2, 1) = rotMat[2][1];
        eigenRotMat(2, 2) = rotMat[2][2];

        return eigenRotMat;
    }

    void setLiDAR2box(Eigen::Matrix4f &box2lidar, string lidarType = "front") {
        Eigen::Translation3f ts;
        if (lidarType == "front") {
            ts = Eigen::Translation3f(0.406, 0.000, 0.344);
        } else if (lidarType == "top") {
            ts = Eigen::Translation3f(0.350, -0.016, 0.384);
        } else {
            throw invalid_argument("Incorrect arguments!");
        }
        // Eigen: w, x, y, z
        Eigen::Quaternionf q(1, 0, 0, 0);
        // pose 오른쪽 term에 box2lidar를 곱하면 pose가 box 기준 -> lidar기준이 된다는 의미에서
        // box2lidar라고 칭함
        // (registration의 src2target tf와는 상반된 표기임!!)
        box2lidar = Eigen::Matrix4f::Identity(); // Crucial!

        auto rotation = q.toRotationMatrix();
        cout << "debug1" << endl;
        for (int i = 0; i < 3; ++i) {
            for (int j = 0; j < 3; ++j) {
                box2lidar(i, j) = rotation(i, j);
            }
        }
        cout << "debug2" << endl;
        box2lidar(0, 3) = ts.x();
        box2lidar(1, 3) = ts.y();
        box2lidar(2, 3) = ts.z();
    }


    void loopClosureThread() {
        if (loopClosureEnableFlag == false)
            return;

        ros::Rate rate(loopClosureFrequency);
        while (ros::ok()) {
            rate.sleep();
            performLoopClosure();
            visualizeLoopClosure();
        }
    }

    void loopInfoHandler(const std_msgs::Float64MultiArray::ConstPtr &loopMsg) {
        std::lock_guard<std::mutex> lock(mtxLoopInfo);
        if (loopMsg->data.size() != 2)
            return;

        loopInfoVec.push_back(*loopMsg);

        while (loopInfoVec.size() > 5)
            loopInfoVec.pop_front();
    }

    void performLoopClosure() {
        if (cloudKeyPoses3D->points.empty() == true)
            return;

        mtx.lock();
        *copy_cloudKeyPoses3D = *cloudKeyPoses3D;
        *copy_cloudKeyPoses6D = *cloudKeyPoses6D;
        mtx.unlock();

        // find keys
        int loopKeyCur;
        int loopKeyPre;
        if (detectLoopClosureExternal(&loopKeyCur, &loopKeyPre) == false)
            if (detectLoopClosureDistance(&loopKeyCur, &loopKeyPre) == false)
                return;

        // extract cloud
        pcl::PointCloud<PointType>::Ptr cureKeyframeCloud(new pcl::PointCloud<PointType>());
        pcl::PointCloud<PointType>::Ptr prevKeyframeCloud(new pcl::PointCloud<PointType>());
        {
            loopFindNearKeyframes(cureKeyframeCloud, loopKeyCur, 0);
            loopFindNearKeyframes(prevKeyframeCloud, loopKeyPre, historyKeyframeSearchNum);
            if (cureKeyframeCloud->size() < 300 || prevKeyframeCloud->size() < 1000)
                return;
            if (pubHistoryKeyFrames.getNumSubscribers() != 0)
                publishCloud(&pubHistoryKeyFrames, prevKeyframeCloud, timeLaserInfoStamp, odometryFrame);
        }

        // ICP Settings
        static pcl::IterativeClosestPoint<PointType, PointType> icp;
        icp.setMaxCorrespondenceDistance(historyKeyframeSearchRadius * 2);
        icp.setMaximumIterations(100);
        icp.setTransformationEpsilon(1e-6);
        icp.setEuclideanFitnessEpsilon(1e-6);
        icp.setRANSACIterations(0);

        // Align clouds
        icp.setInputSource(cureKeyframeCloud);
        icp.setInputTarget(prevKeyframeCloud);
        pcl::PointCloud<PointType>::Ptr unused_result(new pcl::PointCloud<PointType>());
        icp.align(*unused_result);

        if (icp.hasConverged() == false || icp.getFitnessScore() > historyKeyframeFitnessScore)
            return;

        // publish corrected cloud
        if (pubIcpKeyFrames.getNumSubscribers() != 0) {
            pcl::PointCloud<PointType>::Ptr closed_cloud(new pcl::PointCloud<PointType>());
            pcl::transformPointCloud(*cureKeyframeCloud, *closed_cloud, icp.getFinalTransformation());
            publishCloud(&pubIcpKeyFrames, closed_cloud, timeLaserInfoStamp, odometryFrame);
        }

        // Get pose transformation
        float           x, y, z, roll, pitch, yaw;
        Eigen::Affine3f correctionLidarFrame;
        correctionLidarFrame = icp.getFinalTransformation();
        // transform from world origin to wrong pose
        Eigen::Affine3f tWrong   = pclPointToAffine3f(copy_cloudKeyPoses6D->points[loopKeyCur]);
        // transform from world origin to corrected pose
        Eigen::Affine3f tCorrect = correctionLidarFrame * tWrong;// pre-multiplying -> successive rotation about a fixed frame
        pcl::getTranslationAndEulerAngles(tCorrect, x, y, z, roll, pitch, yaw);
        gtsam::Pose3  poseFrom   = Pose3(Rot3::RzRyRx(roll, pitch, yaw), Point3(x, y, z));
        gtsam::Pose3  poseTo     = pclPointTogtsamPose3(copy_cloudKeyPoses6D->points[loopKeyPre]);
        gtsam::Vector Vector6(6);
        float         noiseScore = icp.getFitnessScore();
        Vector6 << noiseScore, noiseScore, noiseScore, noiseScore, noiseScore, noiseScore;
        noiseModel::Diagonal::shared_ptr constraintNoise = noiseModel::Diagonal::Variances(Vector6);

        // Add pose constraint
        mtx.lock();
        loopIndexQueue.push_back(make_pair(loopKeyCur, loopKeyPre));
        loopPoseQueue.push_back(poseFrom.between(poseTo));
        loopNoiseQueue.push_back(constraintNoise);
        mtx.unlock();

        // add loop constriant
        loopIndexContainer[loopKeyCur] = loopKeyPre;
    }

    bool detectLoopClosureDistance(int *latestID, int *closestID) {
        int loopKeyCur = copy_cloudKeyPoses3D->size() - 1;
        int loopKeyPre = -1;

        // check loop constraint added before
        auto it = loopIndexContainer.find(loopKeyCur);
        if (it != loopIndexContainer.end())
            return false;

        // find the closest history key frame
        std::vector<int>   pointSearchIndLoop;
        std::vector<float> pointSearchSqDisLoop;
        kdtreeHistoryKeyPoses->setInputCloud(copy_cloudKeyPoses3D);
        kdtreeHistoryKeyPoses->radiusSearch(copy_cloudKeyPoses3D->back(), historyKeyframeSearchRadius, pointSearchIndLoop,
                                            pointSearchSqDisLoop, 0);

        for (int i = 0; i < (int) pointSearchIndLoop.size(); ++i) {
            int id = pointSearchIndLoop[i];
            if (abs(copy_cloudKeyPoses6D->points[id].time - timeLaserInfoCur) > historyKeyframeSearchTimeDiff) {
                loopKeyPre = id;
                break;
            }
        }

        if (loopKeyPre == -1 || loopKeyCur == loopKeyPre)
            return false;

        *latestID  = loopKeyCur;
        *closestID = loopKeyPre;

        return true;
    }

    bool detectLoopClosureExternal(int *latestID, int *closestID) {
        // this function is not used yet, please ignore it
        int loopKeyCur = -1;
        int loopKeyPre = -1;

        std::lock_guard<std::mutex> lock(mtxLoopInfo);
        if (loopInfoVec.empty())
            return false;

        double loopTimeCur = loopInfoVec.front().data[0];
        double loopTimePre = loopInfoVec.front().data[1];
        loopInfoVec.pop_front();

        if (abs(loopTimeCur - loopTimePre) < historyKeyframeSearchTimeDiff)
            return false;

        int cloudSize = copy_cloudKeyPoses6D->size();
        if (cloudSize < 2)
            return false;

        // latest key
        loopKeyCur = cloudSize - 1;
        for (int i = cloudSize - 1; i >= 0; --i) {
            if (copy_cloudKeyPoses6D->points[i].time >= loopTimeCur)
                loopKeyCur = round(copy_cloudKeyPoses6D->points[i].intensity);
            else
                break;
        }

        // previous key
        loopKeyPre = 0;
        for (int i = 0; i < cloudSize; ++i) {
            if (copy_cloudKeyPoses6D->points[i].time <= loopTimePre)
                loopKeyPre = round(copy_cloudKeyPoses6D->points[i].intensity);
            else
                break;
        }

        if (loopKeyCur == loopKeyPre)
            return false;

        auto it = loopIndexContainer.find(loopKeyCur);
        if (it != loopIndexContainer.end())
            return false;

        *latestID  = loopKeyCur;
        *closestID = loopKeyPre;

        return true;
    }

    void loopFindNearKeyframes(pcl::PointCloud<PointType>::Ptr &nearKeyframes, const int &key, const int &searchNum) {
        // extract near keyframes
        nearKeyframes->clear();
        int      cloudSize = copy_cloudKeyPoses6D->size();
        for (int i         = -searchNum; i <= searchNum; ++i) {
            int keyNear = key + i;
            if (keyNear < 0 || keyNear >= cloudSize)
                continue;
            *nearKeyframes += *transformPointCloud(cornerCloudKeyFrames[keyNear], &copy_cloudKeyPoses6D->points[keyNear]);
            *nearKeyframes += *transformPointCloud(surfCloudKeyFrames[keyNear], &copy_cloudKeyPoses6D->points[keyNear]);
        }

        if (nearKeyframes->empty())
            return;

        // downsample near keyframes
        pcl::PointCloud<PointType>::Ptr cloud_temp(new pcl::PointCloud<PointType>());
        downSizeFilterICP.setInputCloud(nearKeyframes);
        downSizeFilterICP.filter(*cloud_temp);
        *nearKeyframes = *cloud_temp;
    }

    void visualizeLoopClosure() {
        if (loopIndexContainer.empty())
            return;

        visualization_msgs::MarkerArray markerArray;
        // loop nodes
        visualization_msgs::Marker      markerNode;
        markerNode.header.frame_id    = odometryFrame;
        markerNode.header.stamp       = timeLaserInfoStamp;
        markerNode.action             = visualization_msgs::Marker::ADD;
        markerNode.type               = visualization_msgs::Marker::SPHERE_LIST;
        markerNode.ns                 = "loop_nodes";
        markerNode.id                 = 0;
        markerNode.pose.orientation.w = 1;
        markerNode.scale.x            = 0.3;
        markerNode.scale.y            = 0.3;
        markerNode.scale.z            = 0.3;
        markerNode.color.r            = 0;
        markerNode.color.g            = 0.8;
        markerNode.color.b            = 1;
        markerNode.color.a            = 1;
        // loop edges
        visualization_msgs::Marker markerEdge;
        markerEdge.header.frame_id    = odometryFrame;
        markerEdge.header.stamp       = timeLaserInfoStamp;
        markerEdge.action             = visualization_msgs::Marker::ADD;
        markerEdge.type               = visualization_msgs::Marker::LINE_LIST;
        markerEdge.ns                 = "loop_edges";
        markerEdge.id                 = 1;
        markerEdge.pose.orientation.w = 1;
        markerEdge.scale.x            = 0.1;
        markerEdge.color.r            = 0.9;
        markerEdge.color.g            = 0.9;
        markerEdge.color.b            = 0;
        markerEdge.color.a            = 1;

        for (auto it = loopIndexContainer.begin(); it != loopIndexContainer.end(); ++it) {
            int                  key_cur = it->first;
            int                  key_pre = it->second;
            geometry_msgs::Point p;
            p.x = copy_cloudKeyPoses6D->points[key_cur].x;
            p.y = copy_cloudKeyPoses6D->points[key_cur].y;
            p.z = copy_cloudKeyPoses6D->points[key_cur].z;
            markerNode.points.push_back(p);
            markerEdge.points.push_back(p);
            p.x = copy_cloudKeyPoses6D->points[key_pre].x;
            p.y = copy_cloudKeyPoses6D->points[key_pre].y;
            p.z = copy_cloudKeyPoses6D->points[key_pre].z;
            markerNode.points.push_back(p);
            markerEdge.points.push_back(p);
        }

        markerArray.markers.push_back(markerNode);
        markerArray.markers.push_back(markerEdge);
        pubLoopConstraintEdge.publish(markerArray);
    }


    void updateInitialGuess() {
        // save current transformation before any processing
        incrementalOdometryAffineFront = trans2Affine3f(transformTobeMapped);

        static Eigen::Affine3f lastImuTransformation;
        // initialization
        if (cloudKeyPoses3D->points.empty()) {
            transformTobeMapped[0] = cloudInfo.imuRollInit;
            transformTobeMapped[1] = cloudInfo.imuPitchInit;
            transformTobeMapped[2] = cloudInfo.imuYawInit;

            if (!useImuHeadingInitialization)
                transformTobeMapped[2] = 0;

            lastImuTransformation = pcl::getTransformation(0, 0, 0, cloudInfo.imuRollInit, cloudInfo.imuPitchInit,
                                                           cloudInfo.imuYawInit); // save imu before return;
            return;
        }

        // use imu pre-integration estimation for pose guess
        static bool            lastImuPreTransAvailable = false;
        static Eigen::Affine3f lastImuPreTransformation;
        if (cloudInfo.odomAvailable == true) {
            Eigen::Affine3f transBack = pcl::getTransformation(cloudInfo.initialGuessX, cloudInfo.initialGuessY, cloudInfo.initialGuessZ,
                                                               cloudInfo.initialGuessRoll, cloudInfo.initialGuessPitch,
                                                               cloudInfo.initialGuessYaw);
            if (lastImuPreTransAvailable == false) {
                lastImuPreTransformation = transBack;
                lastImuPreTransAvailable = true;
            } else {
                Eigen::Affine3f transIncre = lastImuPreTransformation.inverse() * transBack;
                Eigen::Affine3f transTobe  = trans2Affine3f(transformTobeMapped);
                Eigen::Affine3f transFinal = transTobe * transIncre;
                pcl::getTranslationAndEulerAngles(transFinal, transformTobeMapped[3], transformTobeMapped[4], transformTobeMapped[5],
                                                  transformTobeMapped[0], transformTobeMapped[1], transformTobeMapped[2]);

                lastImuPreTransformation = transBack;

                lastImuTransformation = pcl::getTransformation(0, 0, 0, cloudInfo.imuRollInit, cloudInfo.imuPitchInit,
                                                               cloudInfo.imuYawInit); // save imu before return;
                return;
            }
        }

        // use imu incremental estimation for pose guess (only rotation)
        if (cloudInfo.imuAvailable == true) {
            Eigen::Affine3f transBack  = pcl::getTransformation(0, 0, 0, cloudInfo.imuRollInit, cloudInfo.imuPitchInit,
                                                                cloudInfo.imuYawInit);
            Eigen::Affine3f transIncre = lastImuTransformation.inverse() * transBack;

            Eigen::Affine3f transTobe  = trans2Affine3f(transformTobeMapped);
            Eigen::Affine3f transFinal = transTobe * transIncre;
            pcl::getTranslationAndEulerAngles(transFinal, transformTobeMapped[3], transformTobeMapped[4], transformTobeMapped[5],
                                              transformTobeMapped[0], transformTobeMapped[1], transformTobeMapped[2]);

            lastImuTransformation = pcl::getTransformation(0, 0, 0, cloudInfo.imuRollInit, cloudInfo.imuPitchInit,
                                                           cloudInfo.imuYawInit); // save imu before return;
            return;
        }
    }

    void extractForLoopClosure() {
        pcl::PointCloud<PointType>::Ptr cloudToExtract(new pcl::PointCloud<PointType>());
        int                             numPoses = cloudKeyPoses3D->size();
        for (int                        i        = numPoses - 1; i >= 0; --i) {
            if ((int) cloudToExtract->size() <= surroundingKeyframeSize)
                cloudToExtract->push_back(cloudKeyPoses3D->points[i]);
            else
                break;
        }

        extractCloud(cloudToExtract);
    }

    void extractNearby() {
        pcl::PointCloud<PointType>::Ptr surroundingKeyPoses(new pcl::PointCloud<PointType>());
        pcl::PointCloud<PointType>::Ptr surroundingKeyPosesDS(new pcl::PointCloud<PointType>());
        std::vector<int>                pointSearchInd;
        std::vector<float>              pointSearchSqDis;

        // extract all the nearby key poses and downsample them
        kdtreeSurroundingKeyPoses->setInputCloud(cloudKeyPoses3D); // create kd-tree
        kdtreeSurroundingKeyPoses->radiusSearch(cloudKeyPoses3D->back(), (double) surroundingKeyframeSearchRadius, pointSearchInd,
                                                pointSearchSqDis);
        for (int i = 0; i < (int) pointSearchInd.size(); ++i) {
            int id = pointSearchInd[i];
            surroundingKeyPoses->push_back(cloudKeyPoses3D->points[id]);
        }

        downSizeFilterSurroundingKeyPoses.setInputCloud(surroundingKeyPoses);
        downSizeFilterSurroundingKeyPoses.filter(*surroundingKeyPosesDS);
        for (auto &pt : surroundingKeyPosesDS->points) {
            kdtreeSurroundingKeyPoses->nearestKSearch(pt, 1, pointSearchInd, pointSearchSqDis);
            pt.intensity = cloudKeyPoses3D->points[pointSearchInd[0]].intensity;
        }

        // also extract some latest key frames in case the robot rotates in one position
        int      numPoses = cloudKeyPoses3D->size();
        for (int i        = numPoses - 1; i >= 0; --i) {
            if (timeLaserInfoCur - cloudKeyPoses6D->points[i].time < 10.0)
                surroundingKeyPosesDS->push_back(cloudKeyPoses3D->points[i]);
            else
                break;
        }

        extractCloud(surroundingKeyPosesDS);
    }

    void extractCloud(pcl::PointCloud<PointType>::Ptr cloudToExtract) {
        // fuse the map
        laserCloudCornerFromMap->clear();
        laserCloudSurfFromMap->clear();
        for (int i = 0; i < (int) cloudToExtract->size(); ++i) {
            if (pointDistance(cloudToExtract->points[i], cloudKeyPoses3D->back()) > surroundingKeyframeSearchRadius)
                continue;

            int thisKeyInd = (int) cloudToExtract->points[i].intensity;
            if (laserCloudMapContainer.find(thisKeyInd) != laserCloudMapContainer.end()) {
                // transformed cloud available
                *laserCloudCornerFromMap += laserCloudMapContainer[thisKeyInd].first;
                *laserCloudSurfFromMap += laserCloudMapContainer[thisKeyInd].second;
            } else {
                // transformed cloud not available
                pcl::PointCloud<PointType> laserCloudCornerTemp = *transformPointCloud(cornerCloudKeyFrames[thisKeyInd],
                                                                                       &cloudKeyPoses6D->points[thisKeyInd]);
                pcl::PointCloud<PointType> laserCloudSurfTemp   = *transformPointCloud(surfCloudKeyFrames[thisKeyInd],
                                                                                       &cloudKeyPoses6D->points[thisKeyInd]);
                *laserCloudCornerFromMap += laserCloudCornerTemp;
                *laserCloudSurfFromMap += laserCloudSurfTemp;
                laserCloudMapContainer[thisKeyInd] = make_pair(laserCloudCornerTemp, laserCloudSurfTemp);
            }

        }

        // Downsample the surrounding corner key frames (or map)
        downSizeFilterCorner.setInputCloud(laserCloudCornerFromMap);
        downSizeFilterCorner.filter(*laserCloudCornerFromMapDS);
        laserCloudCornerFromMapDSNum = laserCloudCornerFromMapDS->size();
        // Downsample the surrounding surf key frames (or map)
        downSizeFilterSurf.setInputCloud(laserCloudSurfFromMap);
        downSizeFilterSurf.filter(*laserCloudSurfFromMapDS);
        laserCloudSurfFromMapDSNum = laserCloudSurfFromMapDS->size();

        // clear map cache if too large
        if (laserCloudMapContainer.size() > 1000)
            laserCloudMapContainer.clear();
    }

    void extractSurroundingKeyFrames() {
        if (cloudKeyPoses3D->points.empty() == true)
            return;

        // if (loopClosureEnableFlag == true)
        // {
        //     extractForLoopClosure();    
        // } else {
        //     extractNearby();
        // }

        extractNearby();
    }

    void downsampleCurrentScan() {
        laserCloudDeskewLastDS->clear();
        downSizeFilterDeskew.setInputCloud(laserCloudDeskewLast);
        downSizeFilterDeskew.filter(*laserCloudDeskewLastDS);

        // Downsample cloud from current scan
        laserCloudCornerLastDS->clear();
        downSizeFilterCorner.setInputCloud(laserCloudCornerLast);
        downSizeFilterCorner.filter(*laserCloudCornerLastDS);
        laserCloudCornerLastDSNum = laserCloudCornerLastDS->size();

        laserCloudSurfLastDS->clear();
        downSizeFilterSurf.setInputCloud(laserCloudSurfLast);
        downSizeFilterSurf.filter(*laserCloudSurfLastDS);
        laserCloudSurfLastDSNum = laserCloudSurfLastDS->size();
    }

    void updatePointAssociateToMap() {
        transPointAssociateToMap = trans2Affine3f(transformTobeMapped);
    }

    void cornerOptimization() {
        updatePointAssociateToMap();

#pragma omp parallel for num_threads(numberOfCores)
        for (int i = 0; i < laserCloudCornerLastDSNum; i++) {
            PointType          pointOri, pointSel, coeff;
            std::vector<int>   pointSearchInd;
            std::vector<float> pointSearchSqDis;

            pointOri = laserCloudCornerLastDS->points[i];
            pointAssociateToMap(&pointOri, &pointSel);
            kdtreeCornerFromMap->nearestKSearch(pointSel, 5, pointSearchInd, pointSearchSqDis);

            cv::Mat matA1(3, 3, CV_32F, cv::Scalar::all(0));
            cv::Mat matD1(1, 3, CV_32F, cv::Scalar::all(0));
            cv::Mat matV1(3, 3, CV_32F, cv::Scalar::all(0));

            if (pointSearchSqDis[4] < 1.0) {
                float    cx = 0, cy = 0, cz = 0;
                for (int j  = 0; j < 5; j++) {
                    cx += laserCloudCornerFromMapDS->points[pointSearchInd[j]].x;
                    cy += laserCloudCornerFromMapDS->points[pointSearchInd[j]].y;
                    cz += laserCloudCornerFromMapDS->points[pointSearchInd[j]].z;
                }
                cx /= 5;
                cy /= 5;
                cz /= 5;

                float    a11 = 0, a12 = 0, a13 = 0, a22 = 0, a23 = 0, a33 = 0;
                for (int j   = 0; j < 5; j++) {
                    float ax = laserCloudCornerFromMapDS->points[pointSearchInd[j]].x - cx;
                    float ay = laserCloudCornerFromMapDS->points[pointSearchInd[j]].y - cy;
                    float az = laserCloudCornerFromMapDS->points[pointSearchInd[j]].z - cz;

                    a11 += ax * ax;
                    a12 += ax * ay;
                    a13 += ax * az;
                    a22 += ay * ay;
                    a23 += ay * az;
                    a33 += az * az;
                }
                a11 /= 5;
                a12 /= 5;
                a13 /= 5;
                a22 /= 5;
                a23 /= 5;
                a33 /= 5;

                matA1.at<float>(0, 0) = a11;
                matA1.at<float>(0, 1) = a12;
                matA1.at<float>(0, 2) = a13;
                matA1.at<float>(1, 0) = a12;
                matA1.at<float>(1, 1) = a22;
                matA1.at<float>(1, 2) = a23;
                matA1.at<float>(2, 0) = a13;
                matA1.at<float>(2, 1) = a23;
                matA1.at<float>(2, 2) = a33;

                cv::eigen(matA1, matD1, matV1);

                if (matD1.at<float>(0, 0) > 3 * matD1.at<float>(0, 1)) {

                    float x0 = pointSel.x;
                    float y0 = pointSel.y;
                    float z0 = pointSel.z;
                    float x1 = cx + 0.1 * matV1.at<float>(0, 0);
                    float y1 = cy + 0.1 * matV1.at<float>(0, 1);
                    float z1 = cz + 0.1 * matV1.at<float>(0, 2);
                    float x2 = cx - 0.1 * matV1.at<float>(0, 0);
                    float y2 = cy - 0.1 * matV1.at<float>(0, 1);
                    float z2 = cz - 0.1 * matV1.at<float>(0, 2);

                    float a012 = sqrt(((x0 - x1) * (y0 - y2) - (x0 - x2) * (y0 - y1)) * ((x0 - x1) * (y0 - y2) - (x0 - x2) * (y0 - y1))
                                      + ((x0 - x1) * (z0 - z2) - (x0 - x2) * (z0 - z1)) * ((x0 - x1) * (z0 - z2) - (x0 - x2) * (z0 - z1))
                                      + ((y0 - y1) * (z0 - z2) - (y0 - y2) * (z0 - z1)) * ((y0 - y1) * (z0 - z2) - (y0 - y2) * (z0 - z1)));

                    float l12 = sqrt((x1 - x2) * (x1 - x2) + (y1 - y2) * (y1 - y2) + (z1 - z2) * (z1 - z2));

                    float la = ((y1 - y2) * ((x0 - x1) * (y0 - y2) - (x0 - x2) * (y0 - y1))
                                + (z1 - z2) * ((x0 - x1) * (z0 - z2) - (x0 - x2) * (z0 - z1))) / a012 / l12;

                    float lb = -((x1 - x2) * ((x0 - x1) * (y0 - y2) - (x0 - x2) * (y0 - y1))
                                 - (z1 - z2) * ((y0 - y1) * (z0 - z2) - (y0 - y2) * (z0 - z1))) / a012 / l12;

                    float lc = -((x1 - x2) * ((x0 - x1) * (z0 - z2) - (x0 - x2) * (z0 - z1))
                                 + (y1 - y2) * ((y0 - y1) * (z0 - z2) - (y0 - y2) * (z0 - z1))) / a012 / l12;

                    float ld2 = a012 / l12;

                    float s = 1 - 0.9 * fabs(ld2);

                    coeff.x         = s * la;
                    coeff.y         = s * lb;
                    coeff.z         = s * lc;
                    coeff.intensity = s * ld2;

                    if (s > 0.1) {
                        laserCloudOriCornerVec[i]  = pointOri;
                        coeffSelCornerVec[i]       = coeff;
                        laserCloudOriCornerFlag[i] = true;
                    }
                }
            }
        }
    }

    void surfOptimization() {
        updatePointAssociateToMap();

#pragma omp parallel for num_threads(numberOfCores)
        for (int i = 0; i < laserCloudSurfLastDSNum; i++) {
            PointType          pointOri, pointSel, coeff;
            std::vector<int>   pointSearchInd;
            std::vector<float> pointSearchSqDis;

            pointOri = laserCloudSurfLastDS->points[i];
            pointAssociateToMap(&pointOri, &pointSel);
            kdtreeSurfFromMap->nearestKSearch(pointSel, 5, pointSearchInd, pointSearchSqDis);

            Eigen::Matrix<float, 5, 3> matA0;
            Eigen::Matrix<float, 5, 1> matB0;
            Eigen::Vector3f            matX0;

            matA0.setZero();
            matB0.fill(-1);
            matX0.setZero();

            if (pointSearchSqDis[4] < 1.0) {
                for (int j = 0; j < 5; j++) {
                    matA0(j, 0) = laserCloudSurfFromMapDS->points[pointSearchInd[j]].x;
                    matA0(j, 1) = laserCloudSurfFromMapDS->points[pointSearchInd[j]].y;
                    matA0(j, 2) = laserCloudSurfFromMapDS->points[pointSearchInd[j]].z;
                }

                matX0 = matA0.colPivHouseholderQr().solve(matB0);

                float pa = matX0(0, 0);
                float pb = matX0(1, 0);
                float pc = matX0(2, 0);
                float pd = 1;

                float ps = sqrt(pa * pa + pb * pb + pc * pc);
                pa /= ps;
                pb /= ps;
                pc /= ps;
                pd /= ps;

                bool     planeValid = true;
                for (int j          = 0; j < 5; j++) {
                    if (fabs(pa * laserCloudSurfFromMapDS->points[pointSearchInd[j]].x +
                             pb * laserCloudSurfFromMapDS->points[pointSearchInd[j]].y +
                             pc * laserCloudSurfFromMapDS->points[pointSearchInd[j]].z + pd) > 0.2) {
                        planeValid = false;
                        break;
                    }
                }

                if (planeValid) {
                    float pd2 = pa * pointSel.x + pb * pointSel.y + pc * pointSel.z + pd;

                    float s = 1 - 0.9 * fabs(pd2) / sqrt(sqrt(pointSel.x * pointSel.x
                                                              + pointSel.y * pointSel.y + pointSel.z * pointSel.z));

                    coeff.x         = s * pa;
                    coeff.y         = s * pb;
                    coeff.z         = s * pc;
                    coeff.intensity = s * pd2;

                    if (s > 0.1) {
                        laserCloudOriSurfVec[i]  = pointOri;
                        coeffSelSurfVec[i]       = coeff;
                        laserCloudOriSurfFlag[i] = true;
                    }
                }
            }
        }
    }

    void combineOptimizationCoeffs() {
        // combine corner coeffs
        for (int i = 0; i < laserCloudCornerLastDSNum; ++i) {
            if (laserCloudOriCornerFlag[i] == true) {
                laserCloudOri->push_back(laserCloudOriCornerVec[i]);
                coeffSel->push_back(coeffSelCornerVec[i]);
            }
        }
        // combine surf coeffs
        for (int i = 0; i < laserCloudSurfLastDSNum; ++i) {
            if (laserCloudOriSurfFlag[i] == true) {
                laserCloudOri->push_back(laserCloudOriSurfVec[i]);
                coeffSel->push_back(coeffSelSurfVec[i]);
            }
        }
        // reset flag for next iteration
        std::fill(laserCloudOriCornerFlag.begin(), laserCloudOriCornerFlag.end(), false);
        std::fill(laserCloudOriSurfFlag.begin(), laserCloudOriSurfFlag.end(), false);
    }

    bool LMOptimization(int iterCount) {
        // This optimization is from the original loam_velodyne by Ji Zhang, need to cope with coordinate transformation
        // lidar <- camera      ---     camera <- lidar
        // x = z                ---     x = y
        // y = x                ---     y = z
        // z = y                ---     z = x
        // roll = yaw           ---     roll = pitch
        // pitch = roll         ---     pitch = yaw
        // yaw = pitch          ---     yaw = roll

        // lidar -> camera
        float srx = sin(transformTobeMapped[1]);
        float crx = cos(transformTobeMapped[1]);
        float sry = sin(transformTobeMapped[2]);
        float cry = cos(transformTobeMapped[2]);
        float srz = sin(transformTobeMapped[0]);
        float crz = cos(transformTobeMapped[0]);

        int laserCloudSelNum = laserCloudOri->size();
        if (laserCloudSelNum < 50) {
            return false;
        }

        cv::Mat matA(laserCloudSelNum, 6, CV_32F, cv::Scalar::all(0));
        cv::Mat matAt(6, laserCloudSelNum, CV_32F, cv::Scalar::all(0));
        cv::Mat matAtA(6, 6, CV_32F, cv::Scalar::all(0));
        cv::Mat matB(laserCloudSelNum, 1, CV_32F, cv::Scalar::all(0));
        cv::Mat matAtB(6, 1, CV_32F, cv::Scalar::all(0));
        cv::Mat matX(6, 1, CV_32F, cv::Scalar::all(0));

        PointType pointOri, coeff;

        for (int i = 0; i < laserCloudSelNum; i++) {
            // lidar -> camera
            pointOri.x      = laserCloudOri->points[i].y;
            pointOri.y      = laserCloudOri->points[i].z;
            pointOri.z      = laserCloudOri->points[i].x;
            // lidar -> camera
            coeff.x         = coeffSel->points[i].y;
            coeff.y         = coeffSel->points[i].z;
            coeff.z         = coeffSel->points[i].x;
            coeff.intensity = coeffSel->points[i].intensity;
            // in camera
            float arx = (crx * sry * srz * pointOri.x + crx * crz * sry * pointOri.y - srx * sry * pointOri.z) * coeff.x
                        + (-srx * srz * pointOri.x - crz * srx * pointOri.y - crx * pointOri.z) * coeff.y
                        + (crx * cry * srz * pointOri.x + crx * cry * crz * pointOri.y - cry * srx * pointOri.z) * coeff.z;

            float ary = ((cry * srx * srz - crz * sry) * pointOri.x
                         + (sry * srz + cry * crz * srx) * pointOri.y + crx * cry * pointOri.z) * coeff.x
                        + ((-cry * crz - srx * sry * srz) * pointOri.x
                           + (cry * srz - crz * srx * sry) * pointOri.y - crx * sry * pointOri.z) * coeff.z;

            float arz = ((crz * srx * sry - cry * srz) * pointOri.x + (-cry * crz - srx * sry * srz) * pointOri.y) * coeff.x
                        + (crx * crz * pointOri.x - crx * srz * pointOri.y) * coeff.y
                        + ((sry * srz + cry * crz * srx) * pointOri.x + (crz * sry - cry * srx * srz) * pointOri.y) * coeff.z;
            // lidar -> camera
            matA.at<float>(i, 0) = arz;
            matA.at<float>(i, 1) = arx;
            matA.at<float>(i, 2) = ary;
            matA.at<float>(i, 3) = coeff.z;
            matA.at<float>(i, 4) = coeff.x;
            matA.at<float>(i, 5) = coeff.y;
            matB.at<float>(i, 0) = -coeff.intensity;
        }

        cv::transpose(matA, matAt);
        matAtA = matAt * matA;
        matAtB = matAt * matB;
        cv::solve(matAtA, matAtB, matX, cv::DECOMP_QR);

        if (iterCount == 0) {

            cv::Mat matE(1, 6, CV_32F, cv::Scalar::all(0));
            cv::Mat matV(6, 6, CV_32F, cv::Scalar::all(0));
            cv::Mat matV2(6, 6, CV_32F, cv::Scalar::all(0));

            cv::eigen(matAtA, matE, matV);
            matV.copyTo(matV2);

            isDegenerate = false;
            float    eignThre[6] = {100, 100, 100, 100, 100, 100};
            for (int i           = 5; i >= 0; i--) {
                if (matE.at<float>(0, i) < eignThre[i]) {
                    for (int j = 0; j < 6; j++) {
                        matV2.at<float>(i, j) = 0;
                    }
                    isDegenerate = true;
                } else {
                    break;
                }
            }
            matP                 = matV.inv() * matV2;
        }

        if (isDegenerate) {
            cv::Mat matX2(6, 1, CV_32F, cv::Scalar::all(0));
            matX.copyTo(matX2);
            matX = matP * matX2;
        }

        transformTobeMapped[0] += matX.at<float>(0, 0);
        transformTobeMapped[1] += matX.at<float>(1, 0);
        transformTobeMapped[2] += matX.at<float>(2, 0);
        transformTobeMapped[3] += matX.at<float>(3, 0);
        transformTobeMapped[4] += matX.at<float>(4, 0);
        transformTobeMapped[5] += matX.at<float>(5, 0);

        float deltaR = sqrt(
                pow(pcl::rad2deg(matX.at<float>(0, 0)), 2) +
                pow(pcl::rad2deg(matX.at<float>(1, 0)), 2) +
                pow(pcl::rad2deg(matX.at<float>(2, 0)), 2));
        float deltaT = sqrt(
                pow(matX.at<float>(3, 0) * 100, 2) +
                pow(matX.at<float>(4, 0) * 100, 2) +
                pow(matX.at<float>(5, 0) * 100, 2));

        if (deltaR < 0.05 && deltaT < 0.05) {
            return true; // converged
        }
        return false; // keep optimizing
    }

    void scan2MapOptimization() {
        if (cloudKeyPoses3D->points.empty())
            return;

        if (laserCloudCornerLastDSNum > edgeFeatureMinValidNum && laserCloudSurfLastDSNum > surfFeatureMinValidNum) {
            kdtreeCornerFromMap->setInputCloud(laserCloudCornerFromMapDS);
            kdtreeSurfFromMap->setInputCloud(laserCloudSurfFromMapDS);

            for (int iterCount = 0; iterCount < 30; iterCount++) {
                laserCloudOri->clear();
                coeffSel->clear();

                cornerOptimization();
                surfOptimization();

                combineOptimizationCoeffs();

                if (LMOptimization(iterCount) == true)
                    break;
            }

            transformUpdate();
        } else {
            ROS_WARN("Not enough features! Only %d edge and %d planar features available.", laserCloudCornerLastDSNum,
                     laserCloudSurfLastDSNum);
        }
    }

    void transformUpdate() {
        if (cloudInfo.imuAvailable == true) {
            if (std::abs(cloudInfo.imuPitchInit) < 1.4) {
                double         imuWeight = imuRPYWeight;
                tf::Quaternion imuQuaternion;
                tf::Quaternion transformQuaternion;
                double         rollMid, pitchMid, yawMid;

                // slerp roll
                transformQuaternion.setRPY(transformTobeMapped[0], 0, 0);
                imuQuaternion.setRPY(cloudInfo.imuRollInit, 0, 0);
                tf::Matrix3x3(transformQuaternion.slerp(imuQuaternion, imuWeight)).getRPY(rollMid, pitchMid, yawMid);
                transformTobeMapped[0] = rollMid;

                // slerp pitch
                transformQuaternion.setRPY(0, transformTobeMapped[1], 0);
                imuQuaternion.setRPY(0, cloudInfo.imuPitchInit, 0);
                tf::Matrix3x3(transformQuaternion.slerp(imuQuaternion, imuWeight)).getRPY(rollMid, pitchMid, yawMid);
                transformTobeMapped[1] = pitchMid;
            }
        }

        transformTobeMapped[0] = constraintTransformation(transformTobeMapped[0], rotation_tollerance);
        transformTobeMapped[1] = constraintTransformation(transformTobeMapped[1], rotation_tollerance);
        transformTobeMapped[5] = constraintTransformation(transformTobeMapped[5], z_tollerance);

        incrementalOdometryAffineBack = trans2Affine3f(transformTobeMapped);
    }

    float constraintTransformation(float value, float limit) {
        if (value < -limit)
            value = -limit;
        if (value > limit)
            value = limit;

        return value;
    }

    bool saveFrame() {
        if (cloudKeyPoses3D->points.empty())
            return true;

        Eigen::Affine3f transStart   = pclPointToAffine3f(cloudKeyPoses6D->back());
        Eigen::Affine3f transFinal   = pcl::getTransformation(transformTobeMapped[3], transformTobeMapped[4], transformTobeMapped[5],
                                                              transformTobeMapped[0], transformTobeMapped[1], transformTobeMapped[2]);
        Eigen::Affine3f transBetween = transStart.inverse() * transFinal;
        float           x, y, z, roll, pitch, yaw;
        pcl::getTranslationAndEulerAngles(transBetween, x, y, z, roll, pitch, yaw);

        if (abs(roll) < surroundingkeyframeAddingAngleThreshold &&
            abs(pitch) < surroundingkeyframeAddingAngleThreshold &&
            abs(yaw) < surroundingkeyframeAddingAngleThreshold &&
            sqrt(x * x + y * y + z * z) < surroundingkeyframeAddingDistThreshold)
            return false;

        return true;
    }

    void addOdomFactor() {
        if (cloudKeyPoses3D->points.empty()) {
            noiseModel::Diagonal::shared_ptr priorNoise = noiseModel::Diagonal::Variances(
                    (Vector(6) << 1e-2, 1e-2, M_PI * M_PI, 1e8, 1e8, 1e8).finished()); // rad*rad, meter*meter
            gtSAMgraph.add(PriorFactor<Pose3>(0, trans2gtsamPose(transformTobeMapped), priorNoise));
            initialEstimate.insert(0, trans2gtsamPose(transformTobeMapped));
        } else {
            noiseModel::Diagonal::shared_ptr odometryNoise = noiseModel::Diagonal::Variances(
                    (Vector(6) << 1e-6, 1e-6, 1e-6, 1e-4, 1e-4, 1e-4).finished());
            gtsam::Pose3                     poseFrom      = pclPointTogtsamPose3(cloudKeyPoses6D->points.back());
            gtsam::Pose3                     poseTo        = trans2gtsamPose(transformTobeMapped);
            gtSAMgraph.add(
                    BetweenFactor<Pose3>(cloudKeyPoses3D->size() - 1, cloudKeyPoses3D->size(), poseFrom.between(poseTo), odometryNoise));
            initialEstimate.insert(cloudKeyPoses3D->size(), poseTo);
        }
    }

    void addGPSFactor() {
        if (gpsQueue.empty())
            return;

        // wait for system initialized and settles down
        if (cloudKeyPoses3D->points.empty())
            return;
        else {
            if (pointDistance(cloudKeyPoses3D->front(), cloudKeyPoses3D->back()) < 5.0)
                return;
        }

        // pose covariance small, no need to correct
        if (poseCovariance(3, 3) < poseCovThreshold && poseCovariance(4, 4) < poseCovThreshold)
            return;

        // last gps position
        static PointType lastGPSPoint;

        while (!gpsQueue.empty()) {
            if (gpsQueue.front().header.stamp.toSec() < timeLaserInfoCur - 0.2) {
                // message too old
                gpsQueue.pop_front();
            } else if (gpsQueue.front().header.stamp.toSec() > timeLaserInfoCur + 0.2) {
                // message too new
                break;
            } else {
                nav_msgs::Odometry thisGPS = gpsQueue.front();
                gpsQueue.pop_front();

                // GPS too noisy, skip
                float noise_x = thisGPS.pose.covariance[0];
                float noise_y = thisGPS.pose.covariance[7];
                float noise_z = thisGPS.pose.covariance[14];
                if (noise_x > gpsCovThreshold || noise_y > gpsCovThreshold)
                    continue;

                float gps_x = thisGPS.pose.pose.position.x;
                float gps_y = thisGPS.pose.pose.position.y;
                float gps_z = thisGPS.pose.pose.position.z;
                if (!useGpsElevation) {
                    gps_z   = transformTobeMapped[5];
                    noise_z = 0.01;
                }

                // GPS not properly initialized (0,0,0)
                if (abs(gps_x) < 1e-6 && abs(gps_y) < 1e-6)
                    continue;

                // Add GPS every a few meters
                PointType curGPSPoint;
                curGPSPoint.x = gps_x;
                curGPSPoint.y = gps_y;
                curGPSPoint.z = gps_z;
                if (pointDistance(curGPSPoint, lastGPSPoint) < 5.0)
                    continue;
                else
                    lastGPSPoint = curGPSPoint;

                gtsam::Vector Vector3(3);
                Vector3 << max(noise_x, 1.0f), max(noise_y, 1.0f), max(noise_z, 1.0f);
                noiseModel::Diagonal::shared_ptr gps_noise = noiseModel::Diagonal::Variances(Vector3);
                gtsam::GPSFactor                 gps_factor(cloudKeyPoses3D->size(), gtsam::Point3(gps_x, gps_y, gps_z), gps_noise);
                gtSAMgraph.add(gps_factor);

                aLoopIsClosed = true;
                break;
            }
        }
    }

    void addLoopFactor() {
        if (loopIndexQueue.empty())
            return;

        for (int i = 0; i < (int) loopIndexQueue.size(); ++i) {
            int                                     indexFrom    = loopIndexQueue[i].first;
            int                                     indexTo      = loopIndexQueue[i].second;
            gtsam::Pose3                            poseBetween  = loopPoseQueue[i];
            gtsam::noiseModel::Diagonal::shared_ptr noiseBetween = loopNoiseQueue[i];
            gtSAMgraph.add(BetweenFactor<Pose3>(indexFrom, indexTo, poseBetween, noiseBetween));
        }

        loopIndexQueue.clear();
        loopPoseQueue.clear();
        loopNoiseQueue.clear();
        aLoopIsClosed = true;
    }

    void saveKeyFramesAndFactor() {
        if (saveFrame() == false)
            return;

        // odom factor
        addOdomFactor();

        // gps factor
        addGPSFactor();

        // loop factor
        addLoopFactor();

        // cout << "****************************************************" << endl;
        // gtSAMgraph.print("GTSAM Graph:\n");

        // update iSAM
        isam->update(gtSAMgraph, initialEstimate);
        isam->update();

        if (aLoopIsClosed == true) {
            isam->update();
            isam->update();
            isam->update();
            isam->update();
            isam->update();
        }

        gtSAMgraph.resize(0);
        initialEstimate.clear();

        //save key poses
        PointType     thisPose3D;
        PointTypePose thisPose6D;
        Pose3         latestEstimate;

        isamCurrentEstimate = isam->calculateEstimate();
        latestEstimate      = isamCurrentEstimate.at<Pose3>(isamCurrentEstimate.size() - 1);
        // cout << "****************************************************" << endl;
        // isamCurrentEstimate.print("Current estimate: ");

        thisPose3D.x         = latestEstimate.translation().x();
        thisPose3D.y         = latestEstimate.translation().y();
        thisPose3D.z         = latestEstimate.translation().z();
        thisPose3D.intensity = cloudKeyPoses3D->size(); // this can be used as index
        cloudKeyPoses3D->push_back(thisPose3D);

        thisPose6D.x         = thisPose3D.x;
        thisPose6D.y         = thisPose3D.y;
        thisPose6D.z         = thisPose3D.z;
        thisPose6D.intensity = thisPose3D.intensity; // this can be used as index
        thisPose6D.roll      = latestEstimate.rotation().roll();
        thisPose6D.pitch     = latestEstimate.rotation().pitch();
        thisPose6D.yaw       = latestEstimate.rotation().yaw();
        thisPose6D.time      = timeLaserInfoCur;
        cloudKeyPoses6D->push_back(thisPose6D);

        // cout << "****************************************************" << endl;
        // cout << "Pose covariance:" << endl;
        // cout << isam->marginalCovariance(isamCurrentEstimate.size()-1) << endl << endl;
        poseCovariance = isam->marginalCovariance(isamCurrentEstimate.size() - 1);

        // save updated transform
        transformTobeMapped[0] = latestEstimate.rotation().roll();
        transformTobeMapped[1] = latestEstimate.rotation().pitch();
        transformTobeMapped[2] = latestEstimate.rotation().yaw();
        transformTobeMapped[3] = latestEstimate.translation().x();
        transformTobeMapped[4] = latestEstimate.translation().y();
        transformTobeMapped[5] = latestEstimate.translation().z();

        // save all the received edge and surf points
        pcl::PointCloud<PointType>::Ptr thisDeskewKeyFrame(new pcl::PointCloud<PointType>());
        pcl::PointCloud<PointType>::Ptr thisCornerKeyFrame(new pcl::PointCloud<PointType>());
        pcl::PointCloud<PointType>::Ptr thisSurfKeyFrame(new pcl::PointCloud<PointType>());

        pcl::copyPointCloud(*laserCloudDeskewLastDS, *thisDeskewKeyFrame);
        pcl::copyPointCloud(*laserCloudCornerLastDS, *thisCornerKeyFrame);
        pcl::copyPointCloud(*laserCloudSurfLastDS, *thisSurfKeyFrame);

        // save key frame cloud
        deskewCloudKeyFrames.push_back(thisDeskewKeyFrame);
        cornerCloudKeyFrames.push_back(thisCornerKeyFrame);
        surfCloudKeyFrames.push_back(thisSurfKeyFrame);

        timestamps.push_back(timeLaserInfoCurToSave);

        // save path for visualization
        updatePath(thisPose6D);
    }

    void correctPoses() {
        if (cloudKeyPoses3D->points.empty())
            return;

        if (aLoopIsClosed == true) {
            // clear map cache
            laserCloudMapContainer.clear();
            // clear path
            globalPath.poses.clear();
            // update key poses
            int      numPoses = isamCurrentEstimate.size();
            for (int i        = 0; i < numPoses; ++i) {
                cloudKeyPoses3D->points[i].x = isamCurrentEstimate.at<Pose3>(i).translation().x();
                cloudKeyPoses3D->points[i].y = isamCurrentEstimate.at<Pose3>(i).translation().y();
                cloudKeyPoses3D->points[i].z = isamCurrentEstimate.at<Pose3>(i).translation().z();

                cloudKeyPoses6D->points[i].x     = cloudKeyPoses3D->points[i].x;
                cloudKeyPoses6D->points[i].y     = cloudKeyPoses3D->points[i].y;
                cloudKeyPoses6D->points[i].z     = cloudKeyPoses3D->points[i].z;
                cloudKeyPoses6D->points[i].roll  = isamCurrentEstimate.at<Pose3>(i).rotation().roll();
                cloudKeyPoses6D->points[i].pitch = isamCurrentEstimate.at<Pose3>(i).rotation().pitch();
                cloudKeyPoses6D->points[i].yaw   = isamCurrentEstimate.at<Pose3>(i).rotation().yaw();

                updatePath(cloudKeyPoses6D->points[i]);
            }

            aLoopIsClosed = false;
        }
    }

    void updatePath(const PointTypePose &pose_in) {
        geometry_msgs::PoseStamped pose_stamped;
        pose_stamped.header.stamp    = ros::Time().fromSec(pose_in.time);
        pose_stamped.header.frame_id = odometryFrame;
        pose_stamped.pose.position.x = pose_in.x;
        pose_stamped.pose.position.y = pose_in.y;
        pose_stamped.pose.position.z = pose_in.z;
        tf::Quaternion q = tf::createQuaternionFromRPY(pose_in.roll, pose_in.pitch, pose_in.yaw);
        pose_stamped.pose.orientation.x = q.x();
        pose_stamped.pose.orientation.y = q.y();
        pose_stamped.pose.orientation.z = q.z();
        pose_stamped.pose.orientation.w = q.w();

        globalPath.poses.push_back(pose_stamped);
    }

    void publishLastMileNode() {
        /***
        * For Lastmile: publish node
        */
        de_msg::node        node;
        geometry_msgs::Pose poseLast;
        poseLast.position.x  = transformTobeMapped[3];
        poseLast.position.y  = transformTobeMapped[4];
        poseLast.position.z  = transformTobeMapped[5];
        poseLast.orientation = tf::createQuaternionMsgFromRollPitchYaw(transformTobeMapped[0],
                                                                       transformTobeMapped[1],
                                                                       transformTobeMapped[2]);

        static int idx = 0;

        pcl::toROSMsg(*laserCloudDeskewLast, node.laser);
        node.idx.data        = idx++;
        node.odom            = poseLast;
        node.header.stamp    = timeLaserInfoStamp;
        node.header.frame_id = odometryFrame;

        pubNode.publish(node);
    }

    void publishOdometry() {
        // Publish odometry for ROS (global)
        nav_msgs::Odometry laserOdometryROS;
        laserOdometryROS.header.stamp                       = timeLaserInfoStamp;
        laserOdometryROS.header.frame_id                    = odometryFrame;
        laserOdometryROS.child_frame_id                     = "odom_mapping";
        laserOdometryROS.pose.pose.position.x               = transformTobeMapped[3];
        laserOdometryROS.pose.pose.position.y               = transformTobeMapped[4];
        laserOdometryROS.pose.pose.position.z               = transformTobeMapped[5];
        laserOdometryROS.pose.pose.orientation              = tf::createQuaternionMsgFromRollPitchYaw(transformTobeMapped[0],
                                                                                                      transformTobeMapped[1],
                                                                                                      transformTobeMapped[2]);

        pubLaserOdometryGlobal.publish(laserOdometryROS);



        // Publish TF
        static tf::TransformBroadcaster br;
        tf::Transform                   t_odom_to_lidar     = tf::Transform(
                tf::createQuaternionFromRPY(transformTobeMapped[0], transformTobeMapped[1], transformTobeMapped[2]),
                tf::Vector3(transformTobeMapped[3], transformTobeMapped[4], transformTobeMapped[5]));
        tf::StampedTransform            trans_odom_to_lidar = tf::StampedTransform(t_odom_to_lidar, timeLaserInfoStamp, odometryFrame,
                                                                                   "lidar_link");
        br.sendTransform(trans_odom_to_lidar);

        // Publish odometry for ROS (incremental)
        static bool               lastIncreOdomPubFlag = false;
        static nav_msgs::Odometry laserOdomIncremental; // incremental odometry msg
        static Eigen::Affine3f    increOdomAffine; // incremental odometry in affine
        if (lastIncreOdomPubFlag == false) {
            lastIncreOdomPubFlag = true;
            laserOdomIncremental = laserOdometryROS;
            increOdomAffine      = trans2Affine3f(transformTobeMapped);
        } else {
            Eigen::Affine3f affineIncre = incrementalOdometryAffineFront.inverse() * incrementalOdometryAffineBack;
            increOdomAffine = increOdomAffine * affineIncre;
            float x, y, z, roll, pitch, yaw;
            pcl::getTranslationAndEulerAngles(increOdomAffine, x, y, z, roll, pitch, yaw);
            if (cloudInfo.imuAvailable == true) {
                if (std::abs(cloudInfo.imuPitchInit) < 1.4) {
                    double         imuWeight = 0.1;
                    tf::Quaternion imuQuaternion;
                    tf::Quaternion transformQuaternion;
                    double         rollMid, pitchMid, yawMid;

                    // slerp roll
                    transformQuaternion.setRPY(roll, 0, 0);
                    imuQuaternion.setRPY(cloudInfo.imuRollInit, 0, 0);
                    tf::Matrix3x3(transformQuaternion.slerp(imuQuaternion, imuWeight)).getRPY(rollMid, pitchMid, yawMid);
                    roll = rollMid;

                    // slerp pitch
                    transformQuaternion.setRPY(0, pitch, 0);
                    imuQuaternion.setRPY(0, cloudInfo.imuPitchInit, 0);
                    tf::Matrix3x3(transformQuaternion.slerp(imuQuaternion, imuWeight)).getRPY(rollMid, pitchMid, yawMid);
                    pitch = pitchMid;
                }
            }
            laserOdomIncremental.header.stamp          = timeLaserInfoStamp;
            laserOdomIncremental.header.frame_id       = odometryFrame;
            laserOdomIncremental.child_frame_id        = "odom_mapping";
            laserOdomIncremental.pose.pose.position.x  = x;
            laserOdomIncremental.pose.pose.position.y  = y;
            laserOdomIncremental.pose.pose.position.z  = z;
            laserOdomIncremental.pose.pose.orientation = tf::createQuaternionMsgFromRollPitchYaw(roll, pitch, yaw);
            if (isDegenerate)
                laserOdomIncremental.pose.covariance[0] = 1;
            else
                laserOdomIncremental.pose.covariance[0] = 0;
        }
        pubLaserOdometryIncremental.publish(laserOdomIncremental);
    }

    void publishFrames() {
        if (cloudKeyPoses3D->points.empty())
            return;
        // publish key poses
        publishCloud(&pubKeyPoses, cloudKeyPoses3D, timeLaserInfoStamp, odometryFrame);
        // Publish surrounding key frames
        publishCloud(&pubRecentKeyFrames, laserCloudSurfFromMapDS, timeLaserInfoStamp, odometryFrame);
        // publish registered key frame
        if (pubRecentKeyFrame.getNumSubscribers() != 0) {
            pcl::PointCloud<PointType>::Ptr cloudOut(new pcl::PointCloud<PointType>());
            PointTypePose                   thisPose6D = trans2PointTypePose(transformTobeMapped);
            *cloudOut += *transformPointCloud(laserCloudCornerLastDS, &thisPose6D);
            *cloudOut += *transformPointCloud(laserCloudSurfLastDS, &thisPose6D);
            publishCloud(&pubRecentKeyFrame, cloudOut, timeLaserInfoStamp, odometryFrame);
        }
        // publish registered high-res raw cloud
        if (pubCloudRegisteredRaw.getNumSubscribers() != 0) {
            pcl::PointCloud<PointType>::Ptr cloudOut(new pcl::PointCloud<PointType>());
            pcl::fromROSMsg(cloudInfo.cloud_deskewed, *cloudOut);
            PointTypePose thisPose6D = trans2PointTypePose(transformTobeMapped);
//            *cloudOut                = *transformPointCloud(cloudOut, &thisPose6D);
            publishCloud(&pubCloudRegisteredRaw, cloudOut, timeLaserInfoStamp, odometryFrame);
        }
        // publish path
        if (pubPath.getNumSubscribers() != 0) {
            globalPath.header.stamp    = timeLaserInfoStamp;
            globalPath.header.frame_id = odometryFrame;
            pubPath.publish(globalPath);
        }
    }
};


int main(int argc, char **argv) {
    ros::init(argc, argv, "lio_sam");

    mapOptimization MO;

    ROS_INFO("\033[1;32m----> Map Optimization Started.\033[0m");

    std::thread loopthread(&mapOptimization::loopClosureThread, &MO);
    std::thread visualizeMapThread(&mapOptimization::visualizeGlobalMapThread, &MO);

    ros::spin();

    loopthread.join();
    visualizeMapThread.join();

    return 0;
}

@llxClover Have you had any success running your own dataset with erasor?