#笔记本配置：i7 10750H+nvidia1650+ubuntu18.04.05
#软件与更新中换源 阿里云；显卡驱动为470版本
主要参考教程：https://blog.csdn.net/jihaoweizzz/article/details/109824857
1.源码安装eigen3.3.9
2.源码安装Pangolin v0.6
3.opencv3.4.5  
  libjasper.dev找不到的话：google到解决办法，复制到这里

  sudo add-apt-repository "deb http://security.ubuntu.com/ubuntu xenial-security main"
  sudo apt update
  sudo apt install libjasper1 libjasper-dev
 
  成功的解决了问题，其中libjasper1是libjasper-dev的依赖包
  参考教程:https://www.jianshu.com/p/f646448da265
  实测4.4.0版本和3.2.0版本opencv在安装时顺利通过编译，但在ORBSLAM3中会报段错误。
4.boost安装：https://www.jianshu.com/p/4c621a34ba69
  版本1.76.0
5.编译orbslam3时会报error:  x3D = x3D_h.get_minor<3,1>(0,0) / x3D_h(3);

  解决方法：https://www.icode9.com/content-3-961807.html
           1./home/dlwlrma/ORB_SLAM3-master/src/cameramodels里的KannalaBrandt8.cpp中搜索"x3D =" ,注
              释掉出错的那句话。
           2./home/dlwlrma/ORB_SLAM3-master/src里的LocalMapping.cc里，替换上版函数。
  void LocalMapping::CreateNewMapPoints()
{
    // Retrieve neighbor keyframes in covisibility graph
    int nn = 10;
    // For stereo inertial case
    if(mbMonocular)
        nn=20;
    vector<KeyFrame*> vpNeighKFs = mpCurrentKeyFrame->GetBestCovisibilityKeyFrames(nn);

    if (mbInertial)
    {
        KeyFrame* pKF = mpCurrentKeyFrame;
        int count=0;
        while((vpNeighKFs.size()<=nn)&&(pKF->mPrevKF)&&(count++<nn))
        {
            vector<KeyFrame*>::iterator it = std::find(vpNeighKFs.begin(), vpNeighKFs.end(), pKF->mPrevKF);
            if(it==vpNeighKFs.end())
                vpNeighKFs.push_back(pKF->mPrevKF);
            pKF = pKF->mPrevKF;
        }
    }

    float th = 0.6f;

    ORBmatcher matcher(th,false);

    cv::Mat Rcw1 = mpCurrentKeyFrame->GetRotation();
    cv::Mat Rwc1 = Rcw1.t();
    cv::Mat tcw1 = mpCurrentKeyFrame->GetTranslation();
    cv::Mat Tcw1(3,4,CV_32F);
    Rcw1.copyTo(Tcw1.colRange(0,3));
    tcw1.copyTo(Tcw1.col(3));
    cv::Mat Ow1 = mpCurrentKeyFrame->GetCameraCenter();

    const float &fx1 = mpCurrentKeyFrame->fx;
    const float &fy1 = mpCurrentKeyFrame->fy;
    const float &cx1 = mpCurrentKeyFrame->cx;
    const float &cy1 = mpCurrentKeyFrame->cy;
    const float &invfx1 = mpCurrentKeyFrame->invfx;
    const float &invfy1 = mpCurrentKeyFrame->invfy;

    const float ratioFactor = 1.5f*mpCurrentKeyFrame->mfScaleFactor;

    // Search matches with epipolar restriction and triangulate
    for(size_t i=0; i<vpNeighKFs.size(); i++)
    {
        if(i>0 && CheckNewKeyFrames())// && (mnMatchesInliers>50))
            return;

        KeyFrame* pKF2 = vpNeighKFs[i];

        GeometricCamera* pCamera1 = mpCurrentKeyFrame->mpCamera, *pCamera2 = pKF2->mpCamera;

        // Check first that baseline is not too short
        cv::Mat Ow2 = pKF2->GetCameraCenter();
        cv::Mat vBaseline = Ow2-Ow1;
        const float baseline = cv::norm(vBaseline);

        if(!mbMonocular)
        {
            if(baseline<pKF2->mb)
            continue;
        }
        else
        {
            const float medianDepthKF2 = pKF2->ComputeSceneMedianDepth(2);
            const float ratioBaselineDepth = baseline/medianDepthKF2;

            if(ratioBaselineDepth<0.01)
                continue;
        }

        // Compute Fundamental Matrix
        cv::Mat F12 = ComputeF12(mpCurrentKeyFrame,pKF2);

        // Search matches that fullfil epipolar constraint
        vector<pair<size_t,size_t> > vMatchedIndices;
        bool bCoarse = mbInertial &&
                ((!mpCurrentKeyFrame->GetMap()->GetIniertialBA2() && mpCurrentKeyFrame->GetMap()->GetIniertialBA1())||
                 mpTracker->mState==Tracking::RECENTLY_LOST);
        matcher.SearchForTriangulation(mpCurrentKeyFrame,pKF2,F12,vMatchedIndices,false,bCoarse);

        cv::Mat Rcw2 = pKF2->GetRotation();
        cv::Mat Rwc2 = Rcw2.t();
        cv::Mat tcw2 = pKF2->GetTranslation();
        cv::Mat Tcw2(3,4,CV_32F);
        Rcw2.copyTo(Tcw2.colRange(0,3));
        tcw2.copyTo(Tcw2.col(3));

        const float &fx2 = pKF2->fx;
        const float &fy2 = pKF2->fy;
        const float &cx2 = pKF2->cx;
        const float &cy2 = pKF2->cy;
        const float &invfx2 = pKF2->invfx;
        const float &invfy2 = pKF2->invfy;

        // Triangulate each match
        const int nmatches = vMatchedIndices.size();
        for(int ikp=0; ikp<nmatches; ikp++)
        {
            const int &idx1 = vMatchedIndices[ikp].first;
            const int &idx2 = vMatchedIndices[ikp].second;

            const cv::KeyPoint &kp1 = (mpCurrentKeyFrame -> NLeft == -1) ? mpCurrentKeyFrame->mvKeysUn[idx1]
                                                                         : (idx1 < mpCurrentKeyFrame -> NLeft) ? mpCurrentKeyFrame -> mvKeys[idx1]
                                                                                                               : mpCurrentKeyFrame -> mvKeysRight[idx1 - mpCurrentKeyFrame -> NLeft];
            const float kp1_ur=mpCurrentKeyFrame->mvuRight[idx1];
            bool bStereo1 = (!mpCurrentKeyFrame->mpCamera2 && kp1_ur>=0);
            const bool bRight1 = (mpCurrentKeyFrame -> NLeft == -1 || idx1 < mpCurrentKeyFrame -> NLeft) ? false
                                                                               : true;

            const cv::KeyPoint &kp2 = (pKF2 -> NLeft == -1) ? pKF2->mvKeysUn[idx2]
                                                            : (idx2 < pKF2 -> NLeft) ? pKF2 -> mvKeys[idx2]
                                                                                     : pKF2 -> mvKeysRight[idx2 - pKF2 -> NLeft];

            const float kp2_ur = pKF2->mvuRight[idx2];
            bool bStereo2 = (!pKF2->mpCamera2 && kp2_ur>=0);
            const bool bRight2 = (pKF2 -> NLeft == -1 || idx2 < pKF2 -> NLeft) ? false
                                                                               : true;

            if(mpCurrentKeyFrame->mpCamera2 && pKF2->mpCamera2){
                if(bRight1 && bRight2){
                    Rcw1 = mpCurrentKeyFrame->GetRightRotation();
                    Rwc1 = Rcw1.t();
                    tcw1 = mpCurrentKeyFrame->GetRightTranslation();
                    Tcw1 = mpCurrentKeyFrame->GetRightPose();
                    Ow1 = mpCurrentKeyFrame->GetRightCameraCenter();

                    Rcw2 = pKF2->GetRightRotation();
                    Rwc2 = Rcw2.t();
                    tcw2 = pKF2->GetRightTranslation();
                    Tcw2 = pKF2->GetRightPose();
                    Ow2 = pKF2->GetRightCameraCenter();

                    pCamera1 = mpCurrentKeyFrame->mpCamera2;
                    pCamera2 = pKF2->mpCamera2;
                }
                else if(bRight1 && !bRight2){
                    Rcw1 = mpCurrentKeyFrame->GetRightRotation();
                    Rwc1 = Rcw1.t();
                    tcw1 = mpCurrentKeyFrame->GetRightTranslation();
                    Tcw1 = mpCurrentKeyFrame->GetRightPose();
                    Ow1 = mpCurrentKeyFrame->GetRightCameraCenter();

                    Rcw2 = pKF2->GetRotation();
                    Rwc2 = Rcw2.t();
                    tcw2 = pKF2->GetTranslation();
                    Tcw2 = pKF2->GetPose();
                    Ow2 = pKF2->GetCameraCenter();

                    pCamera1 = mpCurrentKeyFrame->mpCamera2;
                    pCamera2 = pKF2->mpCamera;
                }
                else if(!bRight1 && bRight2){
                    Rcw1 = mpCurrentKeyFrame->GetRotation();
                    Rwc1 = Rcw1.t();
                    tcw1 = mpCurrentKeyFrame->GetTranslation();
                    Tcw1 = mpCurrentKeyFrame->GetPose();
                    Ow1 = mpCurrentKeyFrame->GetCameraCenter();

                    Rcw2 = pKF2->GetRightRotation();
                    Rwc2 = Rcw2.t();
                    tcw2 = pKF2->GetRightTranslation();
                    Tcw2 = pKF2->GetRightPose();
                    Ow2 = pKF2->GetRightCameraCenter();

                    pCamera1 = mpCurrentKeyFrame->mpCamera;
                    pCamera2 = pKF2->mpCamera2;
                }
                else{
                    Rcw1 = mpCurrentKeyFrame->GetRotation();
                    Rwc1 = Rcw1.t();
                    tcw1 = mpCurrentKeyFrame->GetTranslation();
                    Tcw1 = mpCurrentKeyFrame->GetPose();
                    Ow1 = mpCurrentKeyFrame->GetCameraCenter();

                    Rcw2 = pKF2->GetRotation();
                    Rwc2 = Rcw2.t();
                    tcw2 = pKF2->GetTranslation();
                    Tcw2 = pKF2->GetPose();
                    Ow2 = pKF2->GetCameraCenter();

                    pCamera1 = mpCurrentKeyFrame->mpCamera;
                    pCamera2 = pKF2->mpCamera;
                }
            }

            // Check parallax between rays
            cv::Mat xn1 = pCamera1->unprojectMat(kp1.pt);
            cv::Mat xn2 = pCamera2->unprojectMat(kp2.pt);

            cv::Mat ray1 = Rwc1*xn1;
            cv::Mat ray2 = Rwc2*xn2;
            const float cosParallaxRays = ray1.dot(ray2)/(cv::norm(ray1)*cv::norm(ray2));

            float cosParallaxStereo = cosParallaxRays+1;
            float cosParallaxStereo1 = cosParallaxStereo;
            float cosParallaxStereo2 = cosParallaxStereo;

            if(bStereo1)
                cosParallaxStereo1 = cos(2*atan2(mpCurrentKeyFrame->mb/2,mpCurrentKeyFrame->mvDepth[idx1]));
            else if(bStereo2)
                cosParallaxStereo2 = cos(2*atan2(pKF2->mb/2,pKF2->mvDepth[idx2]));

            cosParallaxStereo = min(cosParallaxStereo1,cosParallaxStereo2);

            cv::Mat x3D;
            if(cosParallaxRays<cosParallaxStereo && cosParallaxRays>0 && (bStereo1 || bStereo2 ||
               (cosParallaxRays<0.9998 && mbInertial) || (cosParallaxRays<0.9998 && !mbInertial)))
            {
                // Linear Triangulation Method
                cv::Mat A(4,4,CV_32F);
                A.row(0) = xn1.at<float>(0)*Tcw1.row(2)-Tcw1.row(0);
                A.row(1) = xn1.at<float>(1)*Tcw1.row(2)-Tcw1.row(1);
                A.row(2) = xn2.at<float>(0)*Tcw2.row(2)-Tcw2.row(0);
                A.row(3) = xn2.at<float>(1)*Tcw2.row(2)-Tcw2.row(1);

                cv::Mat w,u,vt;
                cv::SVD::compute(A,w,u,vt,cv::SVD::MODIFY_A| cv::SVD::FULL_UV);

                x3D = vt.row(3).t();

                if(x3D.at<float>(3)==0)
                    continue;

                // Euclidean coordinates
                x3D = x3D.rowRange(0,3)/x3D.at<float>(3);

            }
            else if(bStereo1 && cosParallaxStereo1<cosParallaxStereo2)
            {
                x3D = mpCurrentKeyFrame->UnprojectStereo(idx1);
            }
            else if(bStereo2 && cosParallaxStereo2<cosParallaxStereo1)
            {
                x3D = pKF2->UnprojectStereo(idx2);
            }
            else
            {
                continue; //No stereo and very low parallax
            }

            cv::Mat x3Dt = x3D.t();

            if(x3Dt.empty()) continue;
            //Check triangulation in front of cameras
            float z1 = Rcw1.row(2).dot(x3Dt)+tcw1.at<float>(2);
            if(z1<=0)
                continue;

            float z2 = Rcw2.row(2).dot(x3Dt)+tcw2.at<float>(2);
            if(z2<=0)
                continue;

            //Check reprojection error in first keyframe
            const float &sigmaSquare1 = mpCurrentKeyFrame->mvLevelSigma2[kp1.octave];
            const float x1 = Rcw1.row(0).dot(x3Dt)+tcw1.at<float>(0);
            const float y1 = Rcw1.row(1).dot(x3Dt)+tcw1.at<float>(1);
            const float invz1 = 1.0/z1;

            if(!bStereo1)
            {
                cv::Point2f uv1 = pCamera1->project(cv::Point3f(x1,y1,z1));
                float errX1 = uv1.x - kp1.pt.x;
                float errY1 = uv1.y - kp1.pt.y;

                if((errX1*errX1+errY1*errY1)>5.991*sigmaSquare1)
                    continue;

            }
            else
            {
                float u1 = fx1*x1*invz1+cx1;
                float u1_r = u1 - mpCurrentKeyFrame->mbf*invz1;
                float v1 = fy1*y1*invz1+cy1;
                float errX1 = u1 - kp1.pt.x;
                float errY1 = v1 - kp1.pt.y;
                float errX1_r = u1_r - kp1_ur;
                if((errX1*errX1+errY1*errY1+errX1_r*errX1_r)>7.8*sigmaSquare1)
                    continue;
            }

            //Check reprojection error in second keyframe
            const float sigmaSquare2 = pKF2->mvLevelSigma2[kp2.octave];
            const float x2 = Rcw2.row(0).dot(x3Dt)+tcw2.at<float>(0);
            const float y2 = Rcw2.row(1).dot(x3Dt)+tcw2.at<float>(1);
            const float invz2 = 1.0/z2;
            if(!bStereo2)
            {
                cv::Point2f uv2 = pCamera2->project(cv::Point3f(x2,y2,z2));
                float errX2 = uv2.x - kp2.pt.x;
                float errY2 = uv2.y - kp2.pt.y;
                if((errX2*errX2+errY2*errY2)>5.991*sigmaSquare2)
                    continue;
            }
            else
            {
                float u2 = fx2*x2*invz2+cx2;
                float u2_r = u2 - mpCurrentKeyFrame->mbf*invz2;
                float v2 = fy2*y2*invz2+cy2;
                float errX2 = u2 - kp2.pt.x;
                float errY2 = v2 - kp2.pt.y;
                float errX2_r = u2_r - kp2_ur;
                if((errX2*errX2+errY2*errY2+errX2_r*errX2_r)>7.8*sigmaSquare2)
                    continue;
            }

            //Check scale consistency
            cv::Mat normal1 = x3D-Ow1;
            float dist1 = cv::norm(normal1);

            cv::Mat normal2 = x3D-Ow2;
            float dist2 = cv::norm(normal2);

            if(dist1==0 || dist2==0)
                continue;

            if(mbFarPoints && (dist1>=mThFarPoints||dist2>=mThFarPoints)) // MODIFICATION
                continue;

            const float ratioDist = dist2/dist1;
            const float ratioOctave = mpCurrentKeyFrame->mvScaleFactors[kp1.octave]/pKF2->mvScaleFactors[kp2.octave];

            if(ratioDist*ratioFactor<ratioOctave || ratioDist>ratioOctave*ratioFactor)
                continue;

            // Triangulation is succesfull
            MapPoint* pMP = new MapPoint(x3D,mpCurrentKeyFrame,mpAtlas->GetCurrentMap());

            pMP->AddObservation(mpCurrentKeyFrame,idx1);            
            pMP->AddObservation(pKF2,idx2);

            mpCurrentKeyFrame->AddMapPoint(pMP,idx1);
            pKF2->AddMapPoint(pMP,idx2);

            pMP->ComputeDistinctiveDescriptors();

            pMP->UpdateNormalAndDepth();

            mpAtlas->AddMapPoint(pMP);
            mlpRecentAddedMapPoints.push_back(pMP);
        }
    }
}
6.运行方式：切入slam文件夹：
./Examples/Monocular/mono_tum Vocabulary/ORBvoc.txt Examples/Monocular/TUM1.yaml /home/jackson/dataset/rgbd_dataset_freiburg1_desk2
其中 /home/...的部分是TUM数据集的位置。