|Message: Coordinate system and placement for Boolean Solids||Not Logged In (login)|
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In all references for Geant4 geometry building that I could find on the web (the manuals seem to explain only the absolute simplest case which is not useful for me), I have learned that boolean solids inherit the coordinate system of the "first" solid used in the operation. For example, if I understand, in the following code:
G4VSolid* returnBox = new G4SubtractionSolid(name,solidBox,enclBox,rm,shift);
G4VSolid* returnBox = new G4UnionSolid(name,solidBox,roofSlice,rm,shift);
Each of the resulting solids should have the coordinate system defined by the "solidBox."
This appears NOT to be the case when I try to place the figures. After making them into logical volumes and then placing them in the mother with the code:
physicalAirBox = new G4PVPlacement(0, positionAirBox, "AirBox_P", logicalAirBox, //physicalVacBox, physicalWorld, false, 0);
Where "logicalAirBox" is the logical volume made from one of the above solids "returnBox" and "physicalWorld" is the physical volume corresponding to the whole world volume. I do not have a good understanding of what the G4PVPlacement argument corresponding to "boolean operation" does, I have it set to false but setting it to true does not change the behaviour.
Can anyone comment on what might be wrong here? I can come up with a concrete and small example, but that will take some time so won't do it unless I have to. The problem is that when I look in the G4 geometry viewer and set to look along the symmetry axis of my shape, panned to align the center of the world with (what I thought should be) the origin of my volume, the volume is shifted off-center.
I am using Geant4.9.3.p02 -- I am in the process of upgrading the simulation to a more modern version but need to fix some geometry issues first.
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