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None Major tracking bug in G4ExtrudedSolid 

Forum: Geometry
Date: 16 Dec, 2014
From: Tom Roberts <Tom Roberts>

Suddenly one of my regression tests is failing. It uses a G4ExtrudedSolid combined with a UserSteppingAction that kills any track that enters the physical volume of the solid. The error is that SOME of the tracks that enter the physical volume are not killed, causing my regression test to fail. SteppingVerbose shows that these tracks never enter the physical volume -- they have steps that are manifestly inside it, but the steps are in volume "World". Other tracks are killed properly at the front face of the physical volume. The extrusion is the only volume in the World, and is displayed correctly in Open Inventor.

This fails in Geant4 version Name: geant4-10-00-patch-02 (13-June-2014)

This works in Geant4 version Name: geant4-09-06-patch-02 (17-May-2013)

This is Mac OS X 10.9.5 (Mavericks). I've checked, and am pretty sure that no relevant G4beamline code changed between those two versions.

Attached is a screen shot of the Open Inventor viewer, looking from downstream of the extrusion toward the rectangular source of the blue beam tracks (the viewer is tilted slightly so the tracks are visible). All beam tracks are parallel to Z. The extrusion is red, and the tracks that hit its triangle in the upper left are not killed, but those in the rest of the extrusion are killed properly (hence not visible). Tracks that miss the extrusion are visible.

The vertices of the extrusion are:
    50,50; 350,50; 350,350; 250,350; 250,250; 150,250; 100,350; 50,250;
This is G4beamline, in which this sort of test is easy; it will take me a while 
to construct a pure Geant4 test case. Note that G4beamline automatically 
reverses the order of vertices if it is wrong. In the image, (x=0,y=0) is in 
the lower left, with X increasing to the right, Y increasing up, and Z out of 
the page.

   Attachment:
      http://hypernews.slac.stanford.edu/HyperNews/geant4/get/AUX/2014/12/16/11.41-99289-4-12-16_at_1.41.11_PM.png

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1 None: Re: Major tracking bug in G4ExtrudedSolid   (Tom Roberts - 16 Dec, 2014)
2 None: Re: Major tracking bug in G4ExtrudedSolid   (Tatiana Nikitina - 17 Dec, 2014)
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