ORB-SLAM2构建稠密地图
参考如下链接：
orbslam2详细
编译过程问题：
1、orbslam2 编译1
build.sh
将j1改为j2可以避免卡死

make -j2

2、build_ros.sh

/usr/bin/ld: CMakeFiles/RGBD.dir/src/ros_rgbd.cc.o: undefined reference to symbol ‘_ZN5boost6system15system_categoryEv’
/usr/lib/x86_64-linux-gnu/libboost_system.so: error adding symbols: DSO missing from command line
collect2: error: ld returned 1 exit status
CMakeFiles/RGBD.dir/build.make:218: recipe for target ‘…/RGBD’ failed
make[2]: *** […/RGBD] Error 1
CMakeFiles/Makefile2:67: recipe for target ‘CMakeFiles/RGBD.dir/all’ failed
make[1]: *** [CMakeFiles/RGBD.dir/all] Error 2
make[1]: *** 正在等待未完成的任务…
/usr/bin/ld: CMakeFiles/Stereo.dir/src/ros_stereo.cc.o: undefined reference to symbol ‘_ZN5boost6system15system_categoryEv’
/usr/lib/x86_64-linux-gnu/libboost_system.so: error adding symbols: DSO missing from command line
collect2: error: ld returned 1 exit status
CMakeFiles/Stereo.dir/build.make:218: recipe for target ‘…/Stereo’ failed
make[2]: *** […/Stereo] Error 1
CMakeFiles/Makefile2:104: recipe for target ‘CMakeFiles/Stereo.dir/all’ failed
make[1]: *** [CMakeFiles/Stereo.dir/all] Error 2
Makefile:127: recipe for target ‘all’ failed
make: *** [all] Error 2

```更改cmake加上一行-lboost_system 
set(LIBS ${OpenCV_LIBS} 
${EIGEN3_LIBS} 
${Pangolin_LIBRARIES} 
${PROJECT_SOURCE_DIR}/../../../Thirdparty/DBoW2/lib/libDBoW2.so 
${PROJECT_SOURCE_DIR}/../../../Thirdparty/g2o/lib/libg2o.so 
${PROJECT_SOURCE_DIR}/../../../lib/libORB_SLAM2.so 
-lboost_system 
)

3、稠密地图
需要将点云保存路径更改为自己的路径