detray

Detray is part of the ACTS project (R&D line for parallelization), the ACTS project can be found: https://github.com/acts-project/acts.

This is a C++17 header only library for detector surface intersections using different algebra plugin libraries. It follows the navigation and propagation concept of ACTS, however, with an attempt to create a geometry without polymorphic inheritance structure.

Repository structure

The code for defining detector surfaces is within the core directory, the algebra plugins are in the plugin directory, and tests are all within the test library.

Testing and benchmarking is done with googletest and google/benchmark.

Getting started

The respository is meant to be possible to build "out of the box", with standard CMake build procedures.

git clone https://github.com/acts-project/detray.git
cmake -DCMAKE_BUILD_TYPE=RelWithDebInfo -S detray -B detray-build
cmake --build detray-build

The following cache variables are available to influence which parts of the project would be built:

• DETRAY_EIGEN_PLUGIN (ON by default), DETRAY_SMATRIX_PLUGIN (OFF by default), DETRAY_VC_PLUGIN (ON by default): Boolean flags turning the build of Eigen, SMatrix and Vc using code on or off.
  • Note that Algebra Plugins must have all of the appropriate options enabled for whichever option is turned on from these.
• DETRAY_IO_CSV: Boolean option turning on the build of detray::io_csv, the library allowing the reading of geometries from CSV files (ON by default);
• DETRAY_DISPLAY: Boolean option turning on the build of detray::display, and additional helpers for displaying a geometry (OFF by default);
• DETRAY_BUILD_CUDA: Boolean option turning on the build of all CUDA code in the repository (ON by default, if CUDA is available);
• DETRAY_BUILD_TESTING: Turn the build/setup of the unit tests on/off (ON by default);
  • DETRAY_BENCHMARKS: Boolean option turning on the build of the benchmark executables (ON by default);
  • DETRAY_BENCHMARKS_MULTITHREAD: Boolean option making the benchmarks multithreaded (OFF by default);
  • DETRAY_BENCHMARKS_REP: String option with an integer for the repetitions that the benchmarks should run (1 by default).

The following options configure how the build should set up the externals that it needs:

• DETRAY_SETUP_<XXX>: Boolean to turn on/off the explicit "setup" of the externals (ALGEBRA_PLUGINS, VECMEM, DFELIBS, MATPLOTPP, THRUST, GOOGLETEST and BENCHMARK);
• DETRAY_USE_SYSTEM_<XXX>: Boolean configuring how to set up a given external
  • ON: The external is searched for "on the system" using find_package;
  • OFF: The package is set up for build as part of this project, using FetchContent.

Benchmark Monitoring

A simple regression benchmark monitoring using google/benchmark runs on merge into master, the results are shown on https://acts-project.github.io/detray/.