C++ interface

This page explains how to create a CMake based C++ project using the Open3D C++ interface.

Note

For help on the C++ interfaces, refer to examples in [examples/Cpp/Test], [examples/Cpp/Experimental] and [src/Tools] folder and check Doxygen document for C++ API.

Install open3d from source

For installing from source see Compiling from source.

Create C++ project

Ubuntu/MacOs

Let’s create a basic C++ project based on CMake and Open3D installed libraries and headers.

  1. Get the code from TestVisualizer.cpp
  2. Get the CMake config file from CMakeLists.txt
  3. Build the project using the following commands:
mkdir -p build
cd build
cmake -DCMAKE_PREFIX_PATH="<Open3D_install_path>/lib/cmake/" ..
make -j

The CMAKE_PREFIX_PATH option is used to tell the CMake where to look for the Open3D installed files. For example, if Open3D was installed to ~/open3d_install, the cmake command would look like this:

cmake -DCMAKE_PREFIX_PATH="~/open3d_install/lib/cmake/" ..

Windows

The steps for creating a C++ project based on the Open3D installed libraries and headers on Windows is very similar.

  1. Copy the TestVisualizer.cpp and CMakeLists.txt files to C:/testVisualizer.
  2. Open CMake GUI and set the source folder to C:/testVisualizer and the binaries folder to C:/testVisualizer/build.
  3. Configure.

At this time you will see that CMake is unable to find Open3D.

../../_images/cpp_project_win.01.Open3D_not_found.png

For simplicity the Open3D install location is C:/open3d_install.

../../_images/cpp_project_win.02.Open3D_install_folder.png

In order for CMake to find the Open3D installed files you need to set Open3D_DIR to the location of the Open3D installed CMake files which is C:/open3d_install/CMake.

  1. Configure. CMake finds Open3D.
../../_images/cpp_project_win.03.Open3D_found.png
  1. Generate. Open the TestVisualizer project and build.

Alternatively, this can be done by calling CMake from the console:

cd Open3D
mkdir build
cd build
cmake -G "Visual Studio 15 2017 Win64" -DCMAKE_INSTALL_PREFIX=C:\open3d_install ..
cmake --build . --parallel %NUMBER_OF_PROCESSORS% --config Release --target install

cd ..\docs\_static\C++\
mkdir build
cd build
cmake -G "Visual Studio 15 2017 Win64" -DCMAKE_PREFIX_PATH=C:\open3d_install ..
cmake --build . --parallel %NUMBER_OF_PROCESSORS% --config Release
Release\TestVisualizer.exe

Highlights

The following fragment from CMakeLists.txt shows how to specify hints to CMake when looking for the Open3D installation. This technique is required when installing Open3D to a user location rather than to a system wide location.

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if(WIN32)
    find_package(Open3D HINTS ${CMAKE_INSTALL_PREFIX}/CMake)
else()
    find_package(Open3D HINTS ${CMAKE_INSTALL_PREFIX}/lib/CMake)
    list(APPEND Open3D_LIBRARIES dl)
endif()

This section of the CMakeLists.txt specifies the installed Open3D include directories, libraries and library directories.

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    link_directories(${Open3D_LIBRARY_DIRS})

    add_executable(TestVisualizer TestVisualizer.cpp)

    target_link_libraries(TestVisualizer ${Open3D_LIBRARIES})

    target_include_directories(TestVisualizer PUBLIC ${Open3D_INCLUDE_DIRS})