<html><body><div style="color:#000; background-color:#fff; font-family:HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif;font-size:12pt"><div class="" style="">Dear GATE Users,</div><div class="" style="">Hi</div><div class="" style="">According to <a href="http://wiki.opengatecollaboration.org/index.php/Users_Guide_V6.1:Defining_a_geometry">WIKI,</a> Three rules must be respected when creating a new volume:</div><div class="" style="">1- A volume which is located inside another must be its daughter.</div><div class="" style="">2- A daughter must be fully included in its mother.</div><div class="" style="">3- Volumes must not overlap.</div><div class="" style=""><br class="" style=""></div><div class="" style="">But I think in "benchSPECT.mac", these rules are not respected!</div><div class="" style="">In this case, "shielding" is daughter of "SPECThead". "collimator", "crystal" & "compartment" are also daughters of "SPECThead", while they are fully located inside the "shielding" and based on rule (1), must be daughter of "shielding" Instead of "SPECThead".</div><div class="" style=""><br class="" style=""></div><div class="" style="">Is that right?</div><div class="" style=""><br class="" style=""></div><div class="" style="">WR,</div><div class="" style="">Babak</div></div></body></html>