When running my application, after some time an event configuration is reached which provokes an infinite loop in G4SubtractionSolid::DistanceToIn(p,v). The message I get is the following: ----------------------------------------------------------- *** Dump for Boolean solid - rB48 *** =================================================== Solid type: G4SubtractionSolid Parameters of constituent solids: =========================================================== ----------------------------------------------------------- *** Dump for solid - B48 *** =================================================== Solid type: G4Box Parameters: half length X: 569 mm half length Y: 2000 mm half length Z: 1828.8 mm ----------------------------------------------------------- ----------------------------------------------------------- *** Dump for Displaced solid - placedB *** =================================================== Solid type: G4DisplacedSolid Parameters of constituent solid: =========================================================== ----------------------------------------------------------- *** Dump for solid - B43s *** =================================================== Solid type: G4Box Parameters: half length X: 300 mm half length Y: 2050 mm half length Z: 10.325 mm ----------------------------------------------------------- =========================================================== Transformations: Direct transformation - translation : (300,0,-1249.475) - rotation : [ ( 1 0 0) ( 0 1 0) ( 0 0 1) ] =========================================================== =========================================================== -------- WWWW ------- G4Exception-START -------- WWWW ------- *** G4Exception : GeomSolids1001 issued by : G4SubtractionSolid::DistanceToIn(p,v) Illegal condition caused by solids: B48 and B43s Looping detected in point (nan,nan,nan), from original point (nan,nan,nan) and direction (0.7903103663410459,-0.4908280694712698,0.3667387777055873) Computed candidate distance: 0*mm. Returning candidate distance. *** This is just a warning message. *** -------- WWWW -------- G4Exception-END --------- WWWW ------- Upon further investigation, I realize that the (nan,nan,nan) coordinates appear in the post-step information of the first step of a secondary electron: ********************************************************************************************************* * G4Track Information: Particle = e-, Track ID = 5115, Parent ID = 5082 ********************************************************************************************************* Step# X(mm) Y(mm) Z(mm) KinE(MeV) dE(MeV) StepLeng TrackLeng NextVolume ProcName 0 -391 959 1.12e+03 1.03 0 0 0 CONC153 initStep >>AlongStepDoIt (after all invocations): ++List of invoked processes 1) CoupledTransportation 2) mesh_DD 3) mesh_DC 4) mesh_DB 5) mesh_DA 6) mesh_FD 7) mesh_FC 8) mesh_FB 9) mesh_FA 10) msc 11) eIoni ++G4Step Information Address of G4Track : 0x4362080 Step Length (mm) : 0.1535850668493046 Energy Deposit (MeV) : 0.05150576776319787 ----------------------------------------------------------------------- StepPoint Information PreStep PostStep ----------------------------------------------------------------------- Position - x (mm) : -390.78879935867 nan Position - y (mm) : 959.2433323881514 nan Position - z (mm) : 1121.774141621281 nan Global Time (ns) : 6.744509893198652 6.745031399582996 Local Time (ns) : 00.0005215063843444881 Proper Time (ns) : 00.0001730161971133884 Momentum Direct - x : nan 0.1578428848227827 Momentum Direct - y : nan -0.1633103342387628 Momentum Direct - z : nan 0.9738661912406885 Momentum - x (MeV/c): nan 0.2207124824514427 Momentum - y (MeV/c): nan -0.2283576438702391 Momentum - z (MeV/c): nan 1.361761886736875 Total Energy (MeV) : 1.540255758733544 1.488749990970346 Kinetic Energy (MeV): 1.029256848733544 0.9777510809703462 Velocity (mm/ns) : 282.8068863977833 281.5758396087471 Volume Name : CONC153 CONC153 Safety (mm) : 0 40.60918201505554 Polarization - x : 0 0 Polarization - y : 0 0 Polarization - Z : 0 0 Weight : 3.041403825178903e-093.041403825178903e-09 Step Status : Undefined PostStep Proc Process defined Step: Undefined eBrem ----------------------------------------------------------------------- ++List of secondaries generated (x,y,z,kE,t,PID): No. of secodaries = 0 **PostStepDoIt (after all invocations): ++List of invoked processes 1) CoupledTransportation 2) msc 3) eBrem (Forced) ++G4Step Information Address of G4Track : 0x4362080 Step Length (mm) : 0.1535850668493046 Energy Deposit (MeV) : 0.05150576776319787 ----------------------------------------------------------------------- StepPoint Information PreStep PostStep ----------------------------------------------------------------------- Position - x (mm) : -390.78879935867 nan Position - y (mm) : 959.2433323881514 nan Position - z (mm) : 1121.774141621281 nan Global Time (ns) : 6.744509893198652 6.745031399582996 Local Time (ns) : 00.0005215063843444881 Proper Time (ns) : 00.0001730161971133884 Momentum Direct - x : nan 0.1552205293158106 Momentum Direct - y : nan -0.1618184922652031 Momentum Direct - z : nan 0.9745364861512041 Momentum - x (MeV/c): nan 0.2161837537753424 Momentum - y (MeV/c): nan -0.2253730820424056 Momentum - z (MeV/c): nan 1.35728796117267 Total Energy (MeV) : 1.540255758733544 1.483535957458107 Kinetic Energy (MeV): 1.029256848733544 0.9725370474581072 Velocity (mm/ns) : 282.8068863977833 281.441110846168 Volume Name : CONC153 CONC153 Safety (mm) : 0 nan Polarization - x : 0 0 Polarization - y : 0 0 Polarization - Z : 0 0 Weight : 3.041403825178903e-093.041403825178903e-09 Step Status : Undefined PostStep Proc Process defined Step: Undefined eBrem ----------------------------------------------------------------------- ++List of secondaries generated (x,y,z,kE,t,PID): No. of secodaries = 1 [Note]Secondaries from AlongStepDoIt included. nan nan nan 0.005214033512239045 6.745031399582996 gamma #Step# X(mm) Y(mm) Z(mm) KinE(MeV) dE(MeV) StepLeng TrackLeng NextVolume ProcName 1 nan nan nan 0.973 0.0515 0.154 0.154 CONC153 eBrem >>AlongStepDoIt (after all invocations): ++List of invoked processes 1) CoupledTransportation 2) mesh_DD 3) mesh_DC 4) mesh_DB 5) mesh_DA 6) mesh_FD 7) mesh_FC 8) mesh_FB 9) mesh_FA 10) msc 11) eIoni ++G4Step Information Address of G4Track : 0x4362080 Step Length (mm) : 0 Energy Deposit (MeV) : 0 ----------------------------------------------------------------------- StepPoint Information PreStep PostStep ----------------------------------------------------------------------- Position - x (mm) : nan nan Position - y (mm) : nan nan Position - z (mm) : nan nan Global Time (ns) : 6.745031399582996 6.745031399582996 Local Time (ns) : 0.00052150638434448810.0005215063843444881 Proper Time (ns) : 0.00017301619711338840.0001730161971133884 Momentum Direct - x : 0.1552205293158106 0.1552205293158106 Momentum Direct - y : -0.1618184922652031 -0.1618184922652031 Momentum Direct - z : 0.9745364861512041 0.9745364861512041 Momentum - x (MeV/c): 0.2161837537753424 0.2161837537753424 Momentum - y (MeV/c): -0.2253730820424056 -0.2253730820424056 Momentum - z (MeV/c): 1.35728796117267 1.35728796117267 Total Energy (MeV) : 1.483535957458107 1.483535957458107 Kinetic Energy (MeV): 0.9725370474581072 0.9725370474581072 Velocity (mm/ns) : 281.441110846168 281.441110846168 Volume Name : CONC153 CONC153 Safety (mm) : nan 5e-10 Polarization - x : 0 0 Polarization - y : 0 0 Polarization - Z : 0 0 Weight : 3.041403825178903e-093.041403825178903e-09 Step Status : PostStep Proc AlongStep Proc. Process defined Step: eBrem mesh_FA ----------------------------------------------------------------------- ++List of secondaries generated (x,y,z,kE,t,PID): No. of secodaries = 1 nan nan nan 0.005214033512239045 6.745031399582996 gamma **PostStepDoIt (after all invocations): ++List of invoked processes 1) CoupledTransportation 2) msc 3) eIoni (Forced) ++G4Step Information Address of G4Track : 0x4362080 Step Length (mm) : 0 Energy Deposit (MeV) : 0 ----------------------------------------------------------------------- StepPoint Information PreStep PostStep ----------------------------------------------------------------------- Position - x (mm) : nan nan Position - y (mm) : nan nan Position - z (mm) : nan nan Global Time (ns) : 6.745031399582996 6.745031399582996 Local Time (ns) : 0.00052150638434448810.0005215063843444881 Proper Time (ns) : 0.00017301619711338840.0001730161971133884 Momentum Direct - x : 0.1552205293158106 0.1552205293158106 Momentum Direct - y : -0.1618184922652031 -0.1618184922652031 Momentum Direct - z : 0.9745364861512041 0.9745364861512041 Momentum - x (MeV/c): 0.2161837537753424 0.2161837537753424 Momentum - y (MeV/c): -0.2253730820424056 -0.2253730820424056 Momentum - z (MeV/c): 1.35728796117267 1.35728796117267 Total Energy (MeV) : 1.483535957458107 1.483535957458107 Kinetic Energy (MeV): 0.9725370474581072 0.9725370474581072 Velocity (mm/ns) : 281.441110846168 281.441110846168 Volume Name : CONC153 OutOfWorld Safety (mm) : nan nan Polarization - x : 0 0 Polarization - y : 0 0 Polarization - Z : 0 0 Weight : 3.041403825178903e-093.041403825178903e-09 Step Status : PostStep Proc Process defined Step: eBrem mesh_FA ----------------------------------------------------------------------- ++List of secondaries generated (x,y,z,kE,t,PID): No. of secodaries = 1 [Note]Secondaries from AlongStepDoIt included. nan nan nan 0.005214033512239045 6.745031399582996 gamma #Step# X(mm) Y(mm) Z(mm) KinE(MeV) dE(MeV) StepLeng TrackLeng NextVolume ProcName 2 nan nan nan 0.973 0 0 0.154 OutOfWorld mesh_FA The event then enters the infinite loop when processing the daughter gamma: ********************************************************************************************************* * G4Track Information: Particle = gamma, Track ID = 5122, Parent ID = 5115 ********************************************************************************************************* Step# X(mm) Y(mm) Z(mm) KinE(MeV) dE(MeV) StepLeng TrackLeng NextVolume ProcName 0 nan nan nan 0.00521 0 0 0 World initStep ----------------------------------------------------------- *** Dump for Boolean solid - rB48 *** =================================================== Solid type: G4SubtractionSolid Parameters of constituent solids: =========================================================== ----------------------------------------------------------- *** Dump for solid - B48 *** =================================================== Solid type: G4Box Parameters: half length X: 569 mm half length Y: 2000 mm half length Z: 1828.8 mm ----------------------------------------------------------- ----------------------------------------------------------- *** Dump for Displaced solid - placedB *** =================================================== Solid type: G4DisplacedSolid Parameters of constituent solid: =========================================================== ----------------------------------------------------------- *** Dump for solid - B43s *** =================================================== Solid type: G4Box Parameters: half length X: 300 mm half length Y: 2050 mm half length Z: 10.325 mm ----------------------------------------------------------- =========================================================== Transformations: Direct transformation - translation : (300,0,-1249.475) - rotation : [ ( 1 0 0) ( 0 1 0) ( 0 0 1) ] =========================================================== =========================================================== -------- WWWW ------- G4Exception-START -------- WWWW ------- *** G4Exception : GeomSolids1001 issued by : G4SubtractionSolid::DistanceToIn(p,v) Illegal condition caused by solids: B48 and B43s Looping detected in point (nan,nan,nan), from original point (nan,nan,nan) and direction (0.7903103663410459,-0.4908280694712698,0.3667387777055873) Computed candidate distance: 0*mm. Returning candidate distance. *** This is just a warning message. *** -------- WWWW -------- G4Exception-END --------- WWWW ------- I have checked the coordinates, the PreStep of the e- is inside the volume CONC153, nowhere near a border surface, and no connection to the bodies B48 and B43s mentioned in the Error message. I don't understand what's going on here. At first I thought it had something to do with scoring, but later I found the same issues also when running without scoring. In any case, it is very inconvenient that the error message in the infinite loop quickly makes logfiles explode!
Could you please provide a test case that we can look at to reproduce the problem? Thanks.
Created attachment 282 [details] Application reproducing the problem Dear Gabriele, I have attached the code of my project. It goes immediately into an infinite loop on out UBUNTU-cluster if I run it with the "no_vis_infLoop.mac" macro. Since I use 8 scoring grids, we had to increment the static const G4int fMaxNav = 8; // rename to kMaxNoNav ?? from 8 to 16 both in source/geometry/navigation/include/G4MultiNavigator.hh and source/geometry/navigation/include/G4PathFinder.hh when building GEANT4 on our cluster. I remember deactivating the scoring changed the event histories (why?) so I don't know if this particular event crashes also when turning off scoring. It might even be that on your machine, it doesn't enter the infinite loop at all (but maybe at a later event). I do not have any experience with Valgrind, but it is installed on our cluster, so I could try to use it if this would become necessary. Cheers, Stefan
It seems that this particle was generated with a (nan, nan, nan) momentum and that this is the reason that the solid is not able to give a sensible answer. Momentum Direct - x : nan Momentum Direct - y : nan Momentum Direct - z : nan Momentum - x (MeV/c): nan Momentum - y (MeV/c): nan Momentum - z (MeV/c): nan As this particle is a primary, it seems to be the primary generator which is causing it to have this value of the momentum. Could you please confirm that this is not the problem ? In the meantime, I will try to check too.
Dear John, no, the particle under question is not a primary particle. The primary particle is simply an e- at 18 GeV emitted in +z-direction. What I see is that at a certain point, one of the many (too many?) secondary electrons created when the primary e- hits the beamdump aquires a (nan,nan,nan) position in the first Post-Step process. Then at this position, it creates a daughter photon. The event then enters the infinite loop when processing the daughter gamma. I see that version 4.10.1 just came out, maybe this solves the problem? Stefan
The solid and navigator cannot cope with a problematic direction. Also they will not cause it. Either a physics process or the magnetic field integration (less likely) would need to be the source of the ( NaN, NaN, NaN ) direction. It should be possible to have the 'particleChange' output of physics processes checked to ensure that such a direction is immediately caught. If such a check does not already exist, it should be added in the appropriate checking method. ( This may be optional. ) Until the origin of the incorrect direction is identified, it is difficult to make progress.
The problem has been identified as coming from G4LowEPComptonModel where an argument for arc trigonometric functions was above 1., generating NaN. The author of the bug report confirmed on a private patch that the problem was resolved. The fix has been provided in emlowen-V10-02-05 .
