ACTS is developed in C++ and is built using CMake. Building the core library requires a C++20 compatible compiler, Boost, and Eigen. The following commands will clone the repository, configure, and build the core library:
git clone https://github.com/acts-project/acts <source>
cmake -B <build> -S <source>
cmake --build <build>For a full list of dependencies, including specific versions, see the Prerequisites section below. Build options to activate additional components are described in the Build options section.
The following dependencies are required to build the ACTS core library:
- A C++17 compatible compiler (recent versions of either gcc and clang should work)
- CMake >= 3.14
- Boost >= 1.71 with
filesystem,program_options, andunit_test_framework - Eigen >= 3.3.7
The following dependencies are optional and are needed to build additional components:
- CUDA for the CUDA plugin and the Exa.TrkX plugin and its examples
- DD4hep >= 1.11 for the DD4hep plugin and some examples
- Doxygen >= 1.8.15 for the documentation
- Geant4 for some examples
- HepMC >= 3.2.1 for some examples
- Intel Threading Building Blocks >= 2020.1 for the examples
- ONNX Runtime >= 1.12.0 for the ONNX plugin, the Exa.TrkX plugin and some examples
- Pythia8 for some examples
- ROOT >= 6.20 for the TGeo plugin and the examples
- Sphinx >= 2.0 with Breathe, Exhale, and recommonmark extensions for the documentation
- cugraph for the Exa.TrkX plugin
- libtorch for the Exa.TrkX plugin
- Pybind11 for the Python bindings of the examples
There are some additional dependencies that are automatically provided as part of
the build system.
These are usually not available through the system package manager and can be found in the thirdparty directory.
All external dependencies must be provided prior to building ACTS. Compatible versions of all dependencies are provided e.g. by the LCG releases starting from LCG 102b. For convenience, it is possible to build the required boost and eigen3 dependencies using the ACTS build system; see Build options. Other options are also available and are discussed in the Building Acts section.
Profiling details the prerequisites for profiling the ACTS project with gperftools.
ACTS uses CMake to configure, build, and install the
software. After checking out the repository code into a <source> directory,
CMake is called first to configure the build into a separate <build>
directory. A typical setup is to create a <source>/build directory within the
sources, but this is just a convention; not a requirement. The following command
runs the configuration and searches for the dependencies. The <build>
directory is automatically created.
cmake -B <build> -S <source>The build can be configured via various options that are listed in detail in the Build options section. Options are set on the command line. The previous command could be e.g. modified to
cmake -B <build> -S <source> -DACTS_BUILD_UNITTESTS=on -DACTS_BUILD_FATRAS=onAfter the configuration succeeded, the software is build. This is also done with cmake via the following command
cmake --build <build>This automatically calls the configure build tool, e.g. Make or Ninja. To build only a specific target, the target names has to be separated from the CMake options by --, i.e.
cmake --build <build> -- ActsFatras # to build the Fatras libraryThe build commands are the same regardless of where you are building the software. Depending on your build environment, there are different ways how to make the dependencies available.
If you have access to a machine running CVMFS, e.g. CERNs lxplus login machines, the dependencies can be easily satisfied via a LCG releases available through CVMFS. A setup script is provided to activate a compatible releases that can be used as follows:
cd <source>
source CI/setup_cvmfs_lcg.shAfter sourcing the setup script, you can build ACTS as described above. The
following commands will build ACTS in the <source>/build directory with the
Fatras component.
cd <source>
source CI/setup_cvmfs_lcg.sh
cmake -B build -S . -DACTS_BUILD_FATRAS=on
cmake --build buildA set of container images is available through the ACTS container registry. The following containers are used as part of the continuous integration setup and come with all dependencies pre-installed.
ubuntu2204ubuntu2404
Furthermore, we are also testing on, but do not provide the corresponding containers:
alma9(HEP-specific software from LCG 104 or 105 and gcc13 or clang16)macOS-10.15
:::{attention} We stopped producing fully-contained LCG containers in favor of running LCG based tests directly from CVMFS. :::
To use these locally, you first need to pull the relevant images from the
registry. Stable versions are tagged as vX where X is the version number.
The latest, potentially unstable, version is tagged as latest. To list all
available tags, e.g. for the ubuntu2004 image, you can use the following
command:
docker search --list-tags ghcr.io/acts-project/ubuntu2404The following command then downloads a stable tag of the ubuntu2404 image:
docker pull ghcr.io/acts-project/ubuntu2404:51This should print the image id as part of the output. You can also find out the
image id by running docker images to list all your locally available container
images.
Now, you need to start a shell within the container to run the build. Assuming
that <source> is the path to your source checkout on your host machine, the
following command will make the source directory available as /acts in the
container and start an interactive bash shell
docker run --volume=<source>:/acts:ro --interactive --tty <image> /bin/bashwhere <image> is the image id that was previously mentioned. If you are using the Ubuntu-based image you are already good to go. For the images based on LCG releases, you can now activate the LCG release in the container shell by sourcing a setup script:
container $ source /opt/lcg_view/setup.shBuilding ACTS follows the instructions above with /acts as the source directory, e.g.
container $ cmake -B build -S /acts -DACTS_BUILD_FATRAS=on
container $ cmake --build buildBuilding and running ACTS on your local machine is not officially supported. However, if you have the necessary prerequisites installed it is possible to use it locally. ACTS developers regularly use different Linux distributions and macOS to build and develop ACTS. It is possible to use Spack to more easily install ACTS' dependencies; see the building with Spack page for more information.
(build_docs)=
The documentation uses Doxygen to extract the source code
documentation and Sphinx with the Breathe extension to
generate the documentation website. To build the documentation locally, you
need to have Doxygen version 1.9.5 or newer installed.
Sphinx and a few other dependencies can be installed using the Python
package manager pip:
cd <source>
pip install -r docs/requirements.txt:::{tip} It is strongly recommended to use a virtual environment for this purpose! For example, run
python -m venv docvenv
source docvenv/bin/activateto create a local virtual environment, and then run the pip command above.
:::
To activate the documentation build targets, the ACTS_BUILD_DOCS option has to be set
cmake -B <build> -S <source> -DACTS_BUILD_DOCS=onThen the documentation can be build with this target
cmake --build <build> --target docsThe default option includes the Doxygen, Sphinx, and the Breathe extension, i.e. the source code information can be used in the manually written documentation. An attempt is made to pull in symbols that are cross-referenced from other parts of the documentation. This is not guaranteed to work: in case of errors you will need to manually pull in symbols to be documented.
CMake options can be set by adding -D<OPTION>=<VALUE> to the configuration
command. The following command would e.g. enable the unit tests
cmake -B <build> -S <source> -DACTS_BUILD_UNITTESTS=ONMultiple options can be given. cmake caches the options so that only changed
options must be specified in subsequent calls to configure the project. The
following options are available to configure the project and enable optional
components.
| Option | Description |
|---|---|
| ACTS_PARAMETER_DEFINITIONS_HEADER | Use a different (track) parameter definitions header type: filepath, default: "" |
| ACTS_SOURCELINK_SBO_SIZE | Customize the SBO size used by SourceLink type: string, default: "" |
| ACTS_FORCE_ASSERTIONS | Force assertions regardless of build type type: bool, default: OFF |
| ACTS_USE_SYSTEM_LIBS | Use system libraries by default type: bool, default: OFF |
| ACTS_USE_SYSTEM_ACTSVG | Use the ActSVG system library type: bool, default: ACTS_USE_SYSTEM_LIBS -> OFF |
| ACTS_USE_SYSTEM_COVFIE | Use a system-provided covfie installation type: bool, default: ACTS_USE_SYSTEM_LIBS -> OFF |
| ACTS_USE_SYSTEM_DETRAY | Use a system-provided detray installation type: bool, default: ACTS_USE_SYSTEM_LIBS -> OFF |
| ACTS_USE_SYSTEM_TRACCC | Use a system-provided traccc installation type: bool, default: ACTS_USE_SYSTEM_LIBS -> OFF |
| ACTS_USE_SYSTEM_VECMEM | Use a system-provided vecmem installation type: bool, default: ACTS_USE_SYSTEM_LIBS -> OFF |
| ACTS_USE_SYSTEM_ALGEBRAPLUGINS | Use a system-provided algebra-plugins installation type: bool, default: ACTS_USE_SYSTEM_LIBS -> OFF |
| ACTS_USE_SYSTEM_NLOHMANN_JSON | Use nlohmann::json provided by the system instead of the bundled version type: bool, default: ACTS_USE_SYSTEM_LIBS -> OFF |
| ACTS_USE_SYSTEM_PYBIND11 | Use a system installation of pybind11 type: bool, default: ACTS_USE_SYSTEM_LIBS -> OFF |
| ACTS_USE_SYSTEM_EIGEN3 | Use a system-provided eigen3 type: bool, default: ON |
| ACTS_BUILD_PLUGIN_ACTSVG | Build SVG display plugin type: bool, default: OFF |
| ACTS_BUILD_PLUGIN_CUDA | Build CUDA plugin type: bool, default: OFF |
| ACTS_BUILD_PLUGIN_DD4HEP | Build DD4hep plugin type: bool, default: OFF |
| ACTS_BUILD_PLUGIN_PODIO | Build Podio plugin type: bool, default: OFF |
| ACTS_BUILD_PLUGIN_EDM4HEP | Build EDM4hep plugin type: bool, default: OFF |
| ACTS_BUILD_PLUGIN_FPEMON | Build FPE monitoring plugin type: bool, default: OFF |
| ACTS_BUILD_PLUGIN_GEOMODEL | Build GeoModel plugin type: bool, default: OFF |
| ACTS_BUILD_PLUGIN_TRACCC | Build Traccc plugin type: bool, default: OFF |
| ACTS_BUILD_PLUGIN_GEANT4 | Build Geant4 plugin type: bool, default: OFF |
| ACTS_BUILD_PLUGIN_EXATRKX | Build the Exa.TrkX plugin type: bool, default: OFF |
| ACTS_EXATRKX_ENABLE_ONNX | Build the Onnx backend for the exatrkx plugin type: bool, default: OFF |
| ACTS_EXATRKX_ENABLE_TORCH | Build the torchscript backend for the exatrkx plugin type: bool, default: ON |
| ACTS_EXATRKX_ENABLE_CUDA | Enable CUDA for the exatrkx plugin type: bool, default: OFF |
| ACTS_BUILD_PLUGIN_JSON | Build json plugin type: bool, default: OFF |
| ACTS_BUILD_PLUGIN_LEGACY | Build legacy plugin type: bool, default: OFF |
| ACTS_BUILD_PLUGIN_ONNX | Build ONNX plugin type: bool, default: OFF |
| ACTS_BUILD_PLUGIN_TGEO | Build TGeo plugin type: bool, default: OFF |
| ACTS_SETUP_ANNOY | Explicitly set up Annoy for the project type: bool, default: OFF |
| ACTS_BUILD_PLUGIN_HASHING | Build Hashing plugin type: bool, default: OFF |
| ACTS_BUILD_FATRAS | Build FAst TRAcking Simulation package type: bool, default: OFF |
| ACTS_BUILD_FATRAS_GEANT4 | Build Geant4 Fatras package type: bool, default: OFF |
| ACTS_BUILD_ALIGNMENT | Build Alignment package type: bool, default: OFF |
| ACTS_BUILD_EXAMPLES_DD4HEP | Build DD4hep-based code in the examples type: bool, default: OFF |
| ACTS_BUILD_EXAMPLES_EDM4HEP | Build EDM4hep-based code in the examples type: bool, default: OFF |
| ACTS_BUILD_EXAMPLES_EXATRKX | Build the Exa.TrkX example code type: bool, default: OFF |
| ACTS_BUILD_EXAMPLES_GEANT4 | Build Geant4-based code in the examples type: bool, default: OFF |
| ACTS_BUILD_EXAMPLES_HEPMC3 | Build HepMC3-based code in the examples type: bool, default: OFF |
| ACTS_BUILD_EXAMPLES_HASHING | Build Hashing-based code in the examples type: bool, default: OFF |
| ACTS_BUILD_EXAMPLES_PYTHIA8 | Build Pythia8-based code in the examples type: bool, default: OFF |
| ACTS_BUILD_EXAMPLES_PYTHON_BINDINGS | Build python bindings for the examples type: bool, default: OFF |
| ACTS_BUILD_ANALYSIS_APPS | Build Analysis applications in the examples type: bool, default: OFF |
| ACTS_BUILD_BENCHMARKS | Build benchmarks type: bool, default: OFF |
| ACTS_BUILD_INTEGRATIONTESTS | Build integration tests type: bool, default: OFF |
| ACTS_BUILD_UNITTESTS | Build unit tests type: bool, default: OFF |
| ACTS_BUILD_EXAMPLES_UNITTESTS | Build unit tests type: bool, default: ACTS_BUILD_UNITTESTS AND ACTS_BUILD_EXAMPLES |
| ACTS_BUILD_NONCOMPILE_TESTS | Build tests that check build failure invariants type: bool, default: OFF |
| ACTS_RUN_CLANG_TIDY | Run clang-tidy static analysis type: bool, default: OFF |
| ACTS_BUILD_DOCS | Build documentation type: bool, default: OFF |
| ACTS_SETUP_BOOST | Explicitly set up Boost for the project type: bool, default: ON |
| ACTS_SETUP_EIGEN3 | Explicitly set up Eigen3 for the project type: bool, default: ON |
| ACTS_BUILD_ODD | Build the OpenDataDetector type: bool, default: OFF |
| ACTS_ENABLE_CPU_PROFILING | Enable CPU profiling using gperftools type: bool, default: OFF |
| ACTS_ENABLE_MEMORY_PROFILING | Enable memory profiling using gperftools type: bool, default: OFF |
| ACTS_GPERF_INSTALL_DIR | Hint to help find gperf if profiling is enabled type: string, default: "" |
| ACTS_ENABLE_LOG_FAILURE_THRESHOLD | Enable failing on log messages with level above certain threshold type: bool, default: OFF |
| ACTS_LOG_FAILURE_THRESHOLD | Log level above which an exception should be automatically thrown. If ACTS_ENABLE_LOG_FAILURE_THRESHOLD is set and this is unset, this will enable a runtime check of the log level. type: string, default: "" |
All ACTS-specific options are disabled or empty by default and must be specifically requested.
ACTS comes with a couple of CMakePresets which allow to collect and origanize common configuration workflows. On the surface the current list of presets contains:
devas a base for developer configurations. This enables everything necessary for running the ODD full chain examples with Fatras. It sets the cpp standard to 20, the generator to ninja and enables ccache.perfis similar todevbut tweaked for performance measurements.
In addition to the ACTS-specific options, many generic options are available that modify various aspects of the build. The following options are some of the most common ones. For more details, have a look at the annotated list of useful CMake variables or at the CMake documentation.
| Option | Description |
|---|---|
| CMAKE_BUILD_TYPE | Build type, e.g. Debug or Release; affects compiler flags (if not specified RelWithDebInfo will be used as a default) |
| CMAKE_CXX_COMPILER | Which C++ compiler to use, e.g. g++ or clang++ |
| CMAKE_INSTALL_PREFIX | Where to install ACTS to |
| CMAKE_PREFIX_PATH | Search path for external packages |
The build is also affected by some environment variables. They can be set by prepending them to the configuration call:
DD4hep_DIR=<path/to/dd4hep> cmake -B <build> -S <source>The following environment variables might be useful.
| Environment variable | Description |
|---|---|
| DD4hep_DIR | Search path for the DD4hep installation |
| HepMC3_DIR | Search path for the HepMC3 installation |
| Pythia8_DIR | Search path for the Pythia8 installation |
ACTS comes packaged with a detector modeled using DD4hep that can be used to test your algorithms. It comes equipped with a magnetic field file as well as an already built material map.
It is available via the git submodule feature by performing the following steps (git lfs need to be installed on your machine):
git submodule init
git submodule updateTo use it, you will then need to build ACTS with the ACTS_BUILD_ODD option and then point either LD_LIBRARY_PATH on Linux or
DYLD_LIBRARY_PATH and DD4HEP_LIBRARY_PATH on MacOs to the install path of the ODD factory (for example: build/thirdparty/OpenDataDetector/factory).
You can now use the ODD in the python binding by using:
oddMaterialDeco = acts.IMaterialDecorator.fromFile("PATH_TO_Acts/thirdparty/OpenDataDetector/data/odd-material-maps.root")
detector, trackingGeometry, decorators = getOpenDataDetector(oddMaterialDeco)When using ACTS in your own CMake-based project, you need to include the
following lines in your CMakeLists.txt file:
find_package (Acts COMPONENTS comp1 comp2 ...)where compX are the required components from the ACTS project. See the
cmake output for more information about which components are available.