Hello,
FreeCAD is growing fine and fast.. Thanks a lot for this.
I came to see Geant4 (CERN Particle Simulation tool) where some of you also were activ.
What is Vec Geom compared to FreeCAd or OCC ?
https://github.com/amadio/vecgeom or http://aidasoft.web.cern.ch/USolids
Are some libs developped twice?
Or is it something to ask at OCC ?
Thanks, Lukas.
What is VecGeom ?
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DeepSOIC
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Re: What is VecGeom ?
I have no idea, sorry.
Maybe @keithsloan52 knows something, as he is developing GDML for FreeCAD.
Maybe @keithsloan52 knows something, as he is developing GDML for FreeCAD.
keithsloan52 wrote: Ding!
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keithsloan52
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Re: What is VecGeom ?
Thanks for the heads up was not really aware of VecGeom.
From a quick google round it appears to be a replacement graphics library for Geant4 and ROOT
with aim of being able to have simulations exploit parallel / multicore processors.
For reasons that I don't fully understand, Monte Carlo simulations as required by the Nuclear/Medical/Space/CERN etc take a very long time to run.They require the models to be specified as Computer Solid Graphics rather than BREP as most CAD systems including FreeCAD create.
(FreeCAD using OCC i.e. BREP). Apparently if they tried to work on BREP solids that would take even longer. Given that FEM is happy to work on Meshes this always surprises me.
There have been efforts/experiments to convert STEP to GDML Tessellate objects but these still seem to have run time issues.
There is also some software McCAD that tries to convert BREP represented solids to a number of CSG solids ( GDML solids )
I found a 2018 GSOC project called GeantV https://hepsoftwarefoundation.org/gsoc/ ... GeantV.htm
One part of which was aimed at implementing a facility to allow GDML files to be converted to VecGeom definitions seehttps://hepsoftwarefoundation.org/gsoc/ ... VGDML.html. Not had time to research result.
My FreeCAD GDML workbench https://github.com/KeithSloan/FreeCAD_Python_GDML implements GDML solids as FreeCAD Python objects, so that a GDML file can be imported and the parameters edited via the normal FreeCAD parameter facilities. The parameters of such objects matching the GDML specifications. GDML solids being a much richer set than implemented in the FreeCAD Part workbench.
I am now aware of GEMC https://cnu-jefferson-lab.fandom.com/wiki/GEMC but that is produced by Jefferson the US smaller equivalent of CERN.
From a quick google round it appears to be a replacement graphics library for Geant4 and ROOT
with aim of being able to have simulations exploit parallel / multicore processors.
For reasons that I don't fully understand, Monte Carlo simulations as required by the Nuclear/Medical/Space/CERN etc take a very long time to run.They require the models to be specified as Computer Solid Graphics rather than BREP as most CAD systems including FreeCAD create.
(FreeCAD using OCC i.e. BREP). Apparently if they tried to work on BREP solids that would take even longer. Given that FEM is happy to work on Meshes this always surprises me.
There have been efforts/experiments to convert STEP to GDML Tessellate objects but these still seem to have run time issues.
There is also some software McCAD that tries to convert BREP represented solids to a number of CSG solids ( GDML solids )
I found a 2018 GSOC project called GeantV https://hepsoftwarefoundation.org/gsoc/ ... GeantV.htm
One part of which was aimed at implementing a facility to allow GDML files to be converted to VecGeom definitions seehttps://hepsoftwarefoundation.org/gsoc/ ... VGDML.html. Not had time to research result.
My FreeCAD GDML workbench https://github.com/KeithSloan/FreeCAD_Python_GDML implements GDML solids as FreeCAD Python objects, so that a GDML file can be imported and the parameters edited via the normal FreeCAD parameter facilities. The parameters of such objects matching the GDML specifications. GDML solids being a much richer set than implemented in the FreeCAD Part workbench.
@lalberts Do you have a link?I came to see Geant4 (CERN Particle Simulation tool)
I am now aware of GEMC https://cnu-jefferson-lab.fandom.com/wiki/GEMC but that is produced by Jefferson the US smaller equivalent of CERN.