Issues with Custom geometry in OpenTOPAS

Geometry, Fields and Transportation
1

Geant4 Version: 11.1.3
Operating System: Linux
Compiler/Version:
CMake Version: 3.18.4

Hi all,

Hope you are well!

I am currently using OpenTOPAS as part of my PhD, which wraps and extends the Geant4 toolkit, and wanted to post my question in this forum to see if anyone here has had experience using it as it is related to Geant4.

I am currently trying to create a custom geometry but I am having issues. I am editing an existing parameter file provided by OpenTOPAS, called TsRandomCylindersInComponent.cc, that generates random cylinders within an envelope that can be a sphere, box or cylinder. I am currently trying to add in an ellipsoid as another envelope shape option. The steps I have taken to creating this new geometry are below.

  1. Edit the .cc file to include G4Ellipsoid as an envelope option that can be called for by the user
  2. Placed the .cc and .hh geometry files in extensions folder of OpenTOPAS-build
  3. Added the file paths to DependInfo.cmake in extensions.dir
  4. Added file paths to build.make in extensions.dir
  5. Added component names to link.txt in extensions.dir
  6. Added component names to TsExtensionManager.cc

I then built the geometry using the following commands in the command terminal in the OpenTOPAS-build directory

  • cmake .
  • make -j$(nproc)

Once I complete these steps, I can see that the .cc.o file has been made for my geometry in the extensions.dir folder in the CMakeFiles folder. However, when I try to call for this geometry in a parameter file, I get an error saying it is unsupported component, where the component that I have made is called TsRandomCylindersInComponentTest. The error message is shown below.

“”"
Welcome to TOPAS, Tool for Particle Simulation (Version 4.0)
Loading parameters starting from: /home/Applications/TOPAS-nBio/examples/geometry/cells/generateRandomCylindersTest.txt

Geant4 Data directory has been specified by the
TOPAS_G4_DATA_DIR environment variable as /home/Applications/GEANT4/G4DATA

Geant4 version Name: geant4-11-01-patch-03 [MT] (10-November-2023)
<< in Multi-threaded mode >>
Copyright : Geant4 Collaboration
References : NIM A 506 (2003), 250-303
: IEEE-TNS 53 (2006), 270-278
: NIM A 835 (2016), 186-225
WWW : http://geant4.org/

TOPAS is in MT mode, setting number of threads to: 1

TOPAS set the tolerances based on the World size to:
Surface tolerance = 9e-09 nm, and radial tolerance = 9e-09 nm.
Topas is exiting due to a serious error.
The parameter:Ge/CylindricalEnvelope/Type
refers to an unsupported Component Type: TsRandomCylindersInComponentTest
“”"

I am new to OpenTOPAS (and Geant4) so I am unsure if I am missing a step in creating the geometry. Information on making custom geometry in OpenTOPAS is very limited so I would be grateful for any insight into this from the Geant4 community! Thank you for your help!

Kind regards,
Michaela

2

I don’t think you should be modifying the code in the -build directory. You should put the custom sources, and the updates to .cmake files, into the original source directory (usually, that’s your git clone). Then when you run CMake, it will bring those files into the build area and use them.

From the fact that the error message says it doesn’t recognize the extension name you say you added, my guess is that the stuff you put into the -build directory either wasn’t recognized, or got stomped on by CMake. Try making your changes in the source directory and see if that helps.

3

Hi Michael,

Thank you for your reply! That makes sense, I’ll make my changes in the source directory and will see if it works then. Thank you for the help!

Kind regards,
Michaela