If your geometry is modelled in Geant4 then it is straightforward to export it using my geometry exporter https://bitbucket.org/simoncblyth/g4dae into the DAE file format used by Opticks. This works analogously to the GDML exporter.
G4VPhysicalVolume* world_pv = m_detector->Construct();
G4DAEParser* g4dae = new G4DAEParser ;
G4bool refs = true ;
G4bool recreatePoly = false ;
G4int nodeIndex = -1 ; // so World is volume 0
g4dae->Write(path, world_pv, refs, recreatePoly, nodeIndex );
Getting the event data is currently a little more involved, requiring the G4Cerenkov and G4Scintillation processes to be modified. I intend to streamline this in future, to reduce the amount of code that needs to be duplicated by each user. Examples for Daya Bay:
To use the resulting geometry and event files and do GPU simulations and visualizations you need to install Opticks and dependencies : which require an NVIDIA GPU with at least CUDA compute capability 3.0 (any NVIDIA GPU less than ~3 years old should be OK).
If this setup would take a long time, you could also share the geometry and event files with me to make visualisations.