Korean Ceres-Solver Tutorial

https://lord-is-my-shepherd.notion.site/Tutorial-dc44ccf751f2497faa6667cca6c24a3a

CMake environment for SLAM BackEnd

Ceres, Eigen3 built in

3rd party libraries

$ mkdir thirdparty && cd thirdparty
$ mkdir eigen && cd eigen
$ mkdir build && mkdir install

$ cd ..
$ mkdir ceres && cd ceres
$ mkdir build && mkdir install

Eigen3 build

$ cd thirdparty/eigen && wget https://gitlab.com/libeigen/eigen/-/archive/3.3.9/eigen-3.3.9.tar.gz -O eigen.tar.gz
$ mkdir build && mkdir install
$ tar -zxvf eigen.tar.gz
$ cd build && cmake -DCMAKE_BUILD_TYPE=Release -DCMAKE_INSTALL_PREFIX=../install ../eigen-3.3.9
$ make -j
$ sudo make install

Ceres build file download

$ sudo apt install libgflags-dev libgoogle-glog-dev libsuitesparse-dev
$ cd thirdparty/ceres && wget http://ceres-solver.org/ceres-solver-2.1.0.tar.gz -O ceres.tar.gz
$ mkdir build && mkdir install
$ tar -zxvf ceres.tar.gz

Change the Eigen directory to my Eigen of thridparty

Edit the CmakeLists.cmake file in the ceres-solver-2.1.0 directory

find_package(Eigen3 3.3 REQUIRED)
----->
find_package(Eigen3 3.3 REQUIRED HINTS /your_directory/SLAM_BackEnd/thirdparty/eigen/install/share/eigen3/cmake)
$ cd build && cmake -DCMAKE_BUILD_TYPE=Debug -DCMAKE_INSTALL_PREFIX=../install ../ceres-solver-2.1.0

$ make -j7
$ sudo make install

Run BA

Simple Bundle Adjustment

$ cd build
$ ./simpleBA ../sources/problem-16-22106-pre.txt

Bundle Adjustment

$ cd build
$ ./BA --input=../sources/problem-16-22106-pre.txt --initial_ply=before.ply --final_ply=after.ply

Results (MeshLab)

• Gray: Before Bundle Adjustment
• Orange: After Bundle Adjustment