Problem 1887

Summary: G4CutTubs crash
Product: Geant4 Reporter: Vladimir.Ivantchenko
Component: geometry/solidsAssignee: Evgueni.Tcherniaev
Status: RESOLVED FIXED    
Severity: critical CC: Evgueni.Tcherniaev
Priority: P4    
Version: 10.2   
Hardware: All   
OS: Linux   

Description Vladimir.Ivantchenko 2016-09-07 16:54:30 CEST 
New CMS tracker prepared for 2017 run tried to use CMSG4CutBubs solid to describe geometry of the support structure. Unfortunately, this is not possible due to crash in class constructor in line#125. The check is too strong.

Examples of such solid are following:


 <CutTubs name="PixelForwardInnerDiskOuterRing_seg_1"
rMin="114.850000000000" rMax="117.350000000000" dz="8.750000000000"
startPhi="1.519000000000" deltaPhi="0.138000000000" lx="0.396977347389"
ly="0.006830142398" lz="-0.917802993466" tx="0.000000000000"
ty="-0.000000000000" tz="1.000000000000"/>

<CutTubs name="PixelForwardInnerDiskOuterRing_seg_9"
rMin="114.850000000000" rMax="117.350000000000" dz="10.250000000000"
startPhi="4.626000000000" deltaPhi="0.138000000000" lx="-0.000000000000"
ly="-0.000000000000" lz="-1.000000000000" tx="0.396976074899"
ty="-0.006903705033" tz="0.917802993466"/>

<CutTubs name="PixelForwardInnerDiskInnerRing_seg_7"
rMin="36.850000000000" rMax="39.350000000000" dz="11.500000000000"
startPhi="4.284000000000" deltaPhi="0.587000000000" lx="0.519034630113"
ly="-0.070439789349" lz="-0.851845812820" tx="0.000000000000"
ty="0.000000000000" tz="1.000000000000"/>

<CutTubs name="PixelForwardOuterDiskOuterRing_seg_1"
rMin="165.300000000000" rMax="167.400000000000" dz="7.250000000000"
startPhi="1.547000000000" deltaPhi="0.084000000000" lx="0.445675398753"
ly="0.008113825570" lz="-0.895157865843" tx="0.140831388398"
ty="0.002563931784" tz="0.990030275444"/>

<CutTubs name="PixelForwardOuterDiskOuterRing_seg_9"
rMin="165.300000000000" rMax="167.400000000000" dz="14.000000000000"
startPhi="4.580000000000" deltaPhi="0.078000000000" lx="0.076048884849"
ly="-0.007122847173" lz="-0.997078648935" tx="0.356128404368"
ty="-0.033355495000" tz="0.933841512547"/>

 <CutTubs name="PixelForwardOuterDiskOuterRing_seg_10"
rMin="165.300000000000" rMax="167.400000000000" dz="8.000000000000"
startPhi="4.658000000000" deltaPhi="0.078000000000" lx="0.223951360659"
ly="-0.003446655180" lz="-0.974594227680" tx="0.357644702165"
ty="-0.005504221818" tz="0.933841512547"/>

<CutTubs name="PixelForwardOuterDiskInnerRing_seg_1"
rMin="87.550000000000" rMax="90.050000000000" dz="7.750000000000"
startPhi="1.525000000000" deltaPhi="0.103000000000" lx="0.474673112860"
ly="0.002707409674" lz="-0.880158000509" tx="0.653290351156"
ty="0.003726195078" tz="0.757098297817"/>

<CutTubs name="PixelForwardOuterDiskInnerRing_seg_10"
rMin="87.550000000000" rMax="90.050000000000" dz="7.250000000000"
startPhi="4.597000000000" deltaPhi="0.173000000000" lx="0.500494999912"
ly="-0.014462813885" lz="-0.865618612368" tx="0.359647955152"
ty="-0.010392754054" tz="0.933030191911"/>
Comment 1 Gabriele Cosmo 2016-09-07 16:56:11 CEST 
Can you please report the G4Exception you get from G4CutTubs?
Comment 2 Vladimir.Ivantchenko 2016-09-07 17:02:25 CEST 
More information. The exception is looked like:

 *** G4Exception : GeomSolids0002
    issued by : G4CutTubs::G4CutTubs() Invalid Low or High Normal to 
    Z plane; Crossing Cutted Planes.
    Invalid Norm to Z plane ((0.519035,-0.0704398,-0.851846) and  (0,0,1)) in
    solid: PixelForwardInnerDiskInnerRing_seg_7

By the way, G4Exception printout is incomplete. Normally one should see all parameters of a solid if they are not correct and not only normals.
Comment 3 Evgueni.Tcherniaev 2016-09-14 09:32:38 CEST 
A little change of the parameters of the solid PixelForwardInnerDiskInnerRing_seg_7 can be considered as a quick (temporary) solution of the problem.

First solution: slight change of the inclination of the cut plane (around 1 degree) , normal=(0.503275,-0.0704247,-0.861252) can be use instead of normal=(0.519035,-0.0704398,-0.851846)

Second solution: increase length of the solid, dz=12.0 can be used instead of dz=11.5
Comment 4 Evgueni.Tcherniaev 2016-11-02 17:09:38 CET 
Check for intersection of cutting planes has been disabled as too strict.