have problems add open3d into C++ project

[HugeKangroo]

Describe the bug
Hello, I created a simple C++ project with yaml-cpp. This project can be compiled until I add open3d into my CMakeLists.txt.
the output error messages are:

/usr/bin/ld: CMakeFiles/o3d.dir/main.cpp.o: in function `main':
/home/dusty/Documents/Geometory3D/main.cpp:6: undefined reference to `YAML::LoadFile(std::string const&)'
collect2: error: ld returned 1 exit status
make[3]: *** [CMakeFiles/o3d.dir/build.make:106: o3d] Error 1
make[2]: *** [CMakeFiles/Makefile2:96: CMakeFiles/o3d.dir/all] Error 2
make[1]: *** [CMakeFiles/Makefile2:103: CMakeFiles/o3d.dir/rule] Error 2
make: *** [Makefile:138: o3d] Error 2

Is there something missing or wrong with my CMakeLists.txt ? thanks in advance.

To Reproduce
here is my main.cpp:

#include <iostream>
#include <open3d/Open3D.h>
#include <yaml-cpp/yaml.h>

int main(int, char**) {
        YAML::LoadFile("./config.yaml");
        const std::vector<std::string> files = {
        "../data/models/ROBOX_0.pcd",
        "../data/models/ROBOX_1.pcd",
        "../data/models/ROBOX_2.pcd",
        "../data/models/ROBOX_3.pcd"
    };
    std::vector<std::shared_ptr<open3d::geometry::Geometry>> clouds;
    for(const std::string &file : files){
        auto cloud_ptr = open3d::io::CreatePointCloudFromFile(file);
        open3d::visualization::DrawGeometries({cloud_ptr}, "TestPCDFileFormat", 1920, 1080);
    }

}

and CMakeLists.txt:

cmake_minimum_required(VERSION 3.17)
project(o3d VERSION 0.1.0)

find_package(yaml-cpp REQUIRED)
include_directories("${YAML_CPP_INCLUDE_DIR}")
link_libraries("${YAML_CPP_LIBRARIES}")

find_package(Open3D REQUIRED)
include_directories(${Open3D_INCLUDE_DIRS})
link_libraries(${Open3D_LIBRARIES})

add_executable(o3d main.cpp)

Environment (please complete the following information):

• Operating system: Ubuntu 18.04

• Open3D version: 0.12.0

• Is this remote workstation?: no

• How did you install Open3D?: build from source

• Compiler version (if built from source): gcc 9.3.0

[theNded]

Looks like a YAML linking issue. Does this work?

#include <iostream>
#include <yaml-cpp/yaml.h>

int main(int, char**) {
        YAML::LoadFile("./config.yaml");
        const std::vector<std::string> files = {
        "../data/models/ROBOX_0.pcd",
        "../data/models/ROBOX_1.pcd",
        "../data/models/ROBOX_2.pcd",
        "../data/models/ROBOX_3.pcd"
    };
}

[HugeKangroo]

Thank you for your advice. I have tried it and get same messages:

[build] /usr/bin/ld: CMakeFiles/o3d.dir/main.cpp.o: in function `main':
[build] /home/dusty/Documents/Geometory3D/build/../main.cpp:6: undefined reference to `YAML::LoadFile(std::string const&)'
[build] collect2: error: ld returned 1 exit status
[build] ninja: build stopped: subcommand failed.
[build] Build finished with exit code 1

I also found that if I change link_libraries(${Open3D_LIBRARIES}) to link_libraries(Open3D), the programme will get error:

/usr/bin/ld: CMakeFiles/o3d.dir/main.cpp.o: in function `main':
/home/dusty/Documents/Geometory3D/main.cpp:15: undefined reference to `open3d::io::CreatePointCloudFromFile(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, bool)'
/usr/bin/ld: /home/dusty/Documents/Geometory3D/main.cpp:16: undefined reference to `open3d::visualization::DrawGeometries(std::vector<std::shared_ptr<open3d::geometry::Geometry const>, std::allocator<std::shared_ptr<open3d::geometry::Geometry const> > > const&, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&, int, int, int, int, bool, bool, bool, Eigen::Matrix<double, 3, 1, 0, 3, 1>*, Eigen::Matrix<double, 3, 1, 0, 3, 1>*, Eigen::Matrix<double, 3, 1, 0, 3, 1>*, double*)'
collect2: error: ld returned 1 exit status
make[3]: *** [CMakeFiles/o3d.dir/build.make:105: o3d] Error 1
make[2]: *** [CMakeFiles/Makefile2:96: CMakeFiles/o3d.dir/all] Error 2
make[1]: *** [CMakeFiles/Makefile2:103: CMakeFiles/o3d.dir/rule] Error 2
make: *** [Makefile:138: o3d] Error 2

I also tried other library like fcl, It seems the compilation will get wrong after linking the open3d libraries.

Just for my opinion, I guess there is something wrong with CMakeLists.txt or Open3D .

[HugeKangroo]

Maybe this is the same issue as in: #2286 and #2656

[SoulProtagonist]

instead of "link_libraries(Open3D)" try "link_libraries(Open3D::Open3D)"

[HugeKangroo]

the sentence link_libraries(${Open3D_LIBRARIES}) is equal to link_libraries(Open3D::Open3D)

[cbenitez81]

Seems that this #2286 (comment) solves the problem

[ssheorey]

I can verify that @cbenitez81 's suggestion resolves this. Also, with PR #4387 this is no longer needed. Note that if you need PyTorch Ops or TensorFlow Ops, you will need to build PyTorch / TensorFlow from source with the new CXX11_ABI. This only affects GCC.