|Message: For John Allison: how come I get "unknown faces!!" when hollowing out a box?||Not Logged In (login)|
Click on the Forum title, e.g. on the "Forums by Category" page, to read a sequence of postings to the Forum and its threads all in one page. If you are only interested in one thread or the thread following a specific posting, click the thread or the posting, which takes you to a smaller page, which contains only the part you are interested in and may be easier to navigate.
Messages are "chained" if there are only replies at the first level, i.e. 1/1.html, 1/1/1.html etc. In case of "chained" messages the message number is replaced by the icon and there is no indentation.
Inline: Display the subject line only or also the text of the posting(s); for the choice "All" the "Outline" choices are switched off.
|1||0||1||no text / full text of posting|
|2||1||All||text for level 1 only / text for All postings|
Outline: Choose the depth of the posting thread, successive toggle controls provide increasing detail.
|1||2||1||2 levels / 1 level (original posting)|
|2||3||2||3 levels / 2 levels|
|3||3||All||3 levels / all levels (all postings)|
John, I read all the threads on HyperNews concerning G4SubtractionSolid operations failing to get visualized. But I found the same error when subtracting a G4Box from a G4Box with a translation on the subtracted box that leaves a 0.075 cm thin front wall. According to my calculations this should not be a problem because I should end up with a simple hollow box with five walls 2mm thick, and a front wall 0.5mm thick. This should not pose a problem for visualization, yet it does!!
Also, I was able to visualize a hollow box without doing the small translation for the subtracted volume. So it's the extra wee translation that is problematic for the BooleanProcessor. Yet, I'm fairly certain my box dimensions are good so that I'm not coinciding any surfaces.
Surely that thickness is large enough that surfaces are not getting lost, and are not being fooled into being coincident? How can my 0.075cm gap be concidered as yielding coincident surfaces with my boaxes (seee code list below)? I say it cannot! But apparently the geometry visualization still gets stuffed up. (Using geant4.7.0.p01)
Below is my code, where I have,
houseLength = 10.06*cm; houseWidth = 4.62*cm; houseHeight = 4.62*cm; innerHouseLength = 9.66*cm; innerHouseWidth = 4.22*cm; innerHouseHeight = 4.22*cm; houseThickness = 2.0*mm; houseFrontThickness = 0.5*mm;
--- G4Box* houseOuterWall = new G4Box("HouseOuterWall", 0.5*houseLength, 0.5*houseWidth, 0.5*houseHeight); G4Box* houseInnerWall = new G4Box("HouseInnerWall", 0.5*innerHouseLength, 0.5*innerHouseWidth, 0.5*innerHouseHeight); G4double innerHouseDeltaX = houseThickness - 0.5*(houseLength - innerHouseLength); solidHouse = new G4SubtractionSolid("House",houseOuterWall,houseInnerWall, 0, G4ThreeVector(innerHouseDeltaX,0.,0.) ); logicHouse = new G4LogicalVolume(solidHouse,houseMat,"House",0,0,0);
G4ThreeVector xpHouse(-0.5*houseLength + insulatorThickness + houseThickness, 0., 0.); physHouse = new G4PVPlacement(0, // no rotation wrt mother xpHouse, // at (x,y,z) wrt mother logicHouse, // its logical volume "House", // its name logicWorld, // its mother volume false, // no boolean operations 0); // no particular field
Can you see what the problem might be?
|Inline Depth:||Outline Depth:||Add message:|