Including DAG in GEANT4

[ParticleTruthSeeker]

Hi, what is the best way to include dagmc in a geant4 application using cmake? At the moment I am trying to use DAGSolid and i get the following error when attempting to compile:

DetectorConstruction.cc:284:(.text+0x33a5): undefined reference to `DagSolid::DagSolid(G4String const&, moab::DagMC*, int)'
collect2: error: ld returned 1 exit status

Many thanks

[makeclean]

Thats a great question! You would need to link the libdagsolid.so library, which you will find installed in the lib directory, you can likely choose to use something like Find(dagmc) in your cmake files. I have a big PR in the works regarding Geant4, so you should see some better behaviour from those changes.

[makeclean]

Any chance you can share the repo of your upstream code?

[makeclean]

You could do something like rather than ${dagsolid} you could use ${DAGMC_LIBRARY_DIRS}/libdagsolid.so I think as a hack?

[ParticleTruthSeeker]

You could do something like rather than ${dagsolid} you could use ${DAGMC_LIBRARY_DIRS}/libdagsolid.so I think as a hack?

Sorry for the delay. I will try this and get back to you. I dont have a publicly available repo right now. I am just running some tests to compare the performance and utility of dagmc and its tally system in geant4 vs gdml vs csg and benchmark against openmc as well.

The particular code I am using is a modified Hadr01 example from geant4.

Would be nice to reuse the geometries across code bases.

[makeclean]

Well in that case you should definitely use the new branch - fix_g4_tracking - which implements a number of changes, fixes, and other enhancements - specifically you will have much better performance, especially when building DAGMC with double-down.

[ParticleTruthSeeker]

Well in that case you should definitely use the new branch - fix_g4_tracking - which implements a number of changes, fixes, and other enhancements - specifically you will have much better performance, especially when building DAGMC with double-down.

Ok I will rebuild it. I don't want to side track us too much, but when I was building embree I went down the sycl rabit hole a bit and I found it quite interesting. The particular implementation seems to be intel specific but I came across AdaptiveCPP and subsequently https://arxiv.org/abs/2504.19048 which is kokkos based. Perhaps the ray tracing kernel can be adapted to use these projects instead at some point. Anyway hopefully I can get the meshes in for a start and maybe get some data out of the mesh tallies.

For example