|Message: Making holes in 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)|
There are a few volumes in my geometry which have got holes in them. So far I have had them implemented the GEANT3 way, i.e. by creating subvolumes filled with the same material as the surroundings; a quick search of these forums shows that at least as far as performance is concerned, this is still considered to be the best approach. There are, however, two things I would like to clarify:
1. Section 18.104.22.168 of the Geant Application-Developer Guide (which discusses solids made by Boolean operations) mentions the following: "The constituent solids of a Boolean operation should possibly avoid be composed by sharing all or part of their surfaces. This precaution is necessary in order to avoid the generation of 'fake' surfaces due to precision loss, or errors in the final visualization of the Boolean shape.". Given holes implemented through subvolumes share parts of their surfaces with respective mother volumes, don't they suffer from the same problem? I do occasionally see some visualisation artefacts there;
2. Is there some way of making holes implemented this way truly see-through in Geant visualisation? This is of course purely cosmetic because as far as particle transport is concerned it is the material that counts - but it would come in handy at times. So far I've only tried adjusting transparency of daughter volumes but alas, all it does is make them disappear from the mother.
Any hints will be very much appreciated!
|Inline Depth:||Outline Depth:||Add message:|