OPSim is a set of additions to the Geant4 toolkit that facilitate the implementation of optical photon applications and increase the flexibility and maintainability of developed applications. It also provides interfaces for creating reusable and portable material build code. This tool has been created according to users' needs and perspectives, considering frequently asked questions, most encountered challenges, and evolving needs over time in the optical category of the Geant4 official forum page.

OPSim: This directory includes the header and implementation files of OPSim.

examples: To demonstrate how to use OPSim in an application, we choose OpNovice, one of the examples in Geant4's optical category. This directory contains two versions of the selected application.

examples/OpNovice : This is the original version provided by the Geant4 team.

examples/OpNoviceEx01: This example shows the usage of MaterialPropertiesTable and OpticalSurface classes and their implementations via user interface commands. Only the OPNoviceDetectorConstruction.cc file has been modified from the source files of OPNovice. All other implementation files are the same as in OpNovice. Also, different from the original version, directories named data, macros, and OPSim have been added to the project source directory.

examples/OpNoviceEx02: This example shows how to use VMaterialBuilder class to decouple a material build code from the detector construction code. This example also shows users how to create an app-independent reusable material build code while working on their projects. Only the OPNoviceDetectorConstruction.cc file has been modified from the source files of OPNovice. All other implementation files are the same as in OpNovice. Also, different from the original version, directories named data, macros, reusableMaterials, and OPSim have been added to the project source directory. The directory named reusableMaterials is now application-independent and can be moved across projects.

examples/output: This directory contains one output from every three examples. It should be noted here that the output of all three examples(i.e., printed output of material properties table) is the same as expected.

• Os: Linux (Ubuntu 22.04.2 LTS)
• Architecture: x86_64
• Compiler: GCC 11.3.0
• Geant4.11.1.1

Copy the OPSim directory to the project source directory, where your CMakeList.txt file is located, and add the following two lines of code to the appropriate place of your CMakeList.txt file (for help, you can examine the CMakeList.txt files in the provided example applications).

before the executable target is created:

  add_subdirectory(OPSim)

after the executable target is created:

   target_link_libraries(yourExecutableTarget OPSim ${Geant4_LIBRARIES} )

1. Go to the directory where you installed the OpNovice in your system.

 cd path/To/OpNovice

2. Create a directory named OpNovice-build in the same directory as OpNovice.

 mkdir OpNovice-build

3. Now go inside this build directory and run CMake to generate the Makefiles needed to build the application. Two arguments are passed to CMake. The first argument to CMake is the path to the source directory that includes the CMakeList.txt file. The second argument is the path to the build directory where the generated make files will be located. CMake will now run to configure the build and generate Makefiles.

  cd OpNovice-build
  cmake -S ../OpNovice -B .

5. With the Makefile available, you can now build by simply running make:

 make  

5. The application is now ready to run. If you now list the contents of your build directory, you will notice that the executable OPNovice has been created. The program can be executed in two modes: interactive and batch. To run in an interactive mode:

 ./OPNovice

All versions of OPNovice run in the same way.

If you have any questions or wish to notify of updates and/or modifications please contact:
Mustafa Kandemir ([email protected])

@article{KANDEMIR2023108873,
title = {OPSimTool: A custom tool for optical photon simulation in Geant4},
journal = {Computer Physics Communications},
volume = {292},
pages = {108873},
year = {2023},
issn = {0010-4655},
doi = {https://doi.org/10.1016/j.cpc.2023.108873},
url = {https://www.sciencedirect.com/science/article/pii/S0010465523002187},
author = {Mustafa Kandemir},
keywords = {Scintillators, Scintillation photon, Light collection, Material optical properties, Eljen scintillators}
}