|Message: Re: RE: Optically conected volumes||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)|
> I'd still like a clarification if possible.
> 1. Are surfaces between daughter volumes in the same parent volume just
> defined by their placements being such that two of their surfaces =
> overlap to within a certain geometric tolerance?
Two daughters of the same mother volume must NOT overlap! What you should do is calculate their position such that the flush surface you want exactly touches (within the precision of the computer calculation). The concept of 'touching' is of course within a computational tolerance; for details you need to consult documentation about G4's navigation and global/management/include/G4GeometryTolerance.hh - in general though, the user need not worry about these details, except for the requirement I stated above.
> 2. Does this cause a geometry problem with possible overlap of bounding = > surfaces when tracking other particles?
You dont' want overlaps in your geometry, irrespective of what particles you want to track.
3. Does the definition of a G4LogicalBorderSurface help the geometry or tracking manager solve this problem?
The G4LogicalBorderSurface is assigned to a ORDERED pair of physical volumes. The G4OpBoundaryProcess decides which BorderSurface to fetch from the two pointers it has to the physical volumes on either side of the boundary. Actually, you do not require a BorderSurface if all you want to take into account is Snell's Law between two dielectric media.
To summarize, the G4 navigator is capable of moving between two daughter volumes, and without jumping 'into a void' between them finding itself in the mother, so long as you have calculated the surface to coincide.