Hi,<br><br><div><span class="gmail_quote">2008/2/12, Gilberto Almeida <<a href="mailto:gilberto.s.almeida@gmail.com">gilberto.s.almeida@gmail.com</a>>:</span><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;"> <div class="gmail_quote"><div><br> Thank you, that solved my problem. <br><br> By the way, the two cones are for a pinhole, inserted in a lead collimator. If I put the cones in a box of air, the pinhole will desapeare and the box will be the hole in the colimator. By the ohter side, if I define the material of the box as lead, the collimator will be thicker in the part that isn't pinhole... I don't know if I'm making myself clear... The point is: if I don't define any material for this box, wil it become like a "ghost" in the geometry (I would like so), or GATE will assume a material for it?</div> </div></blockquote><div><br>I've just checked in the source code and it appears that Gate automatically set the material of an object to the same as its mother.<br><br>Cheers,<br>Simon<br></div><br><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;"> <div class="gmail_quote"><div> Once again, thank you for the help<span class="q"><br><br><span><font style="color: rgb(0, 0, 0);" color="#888888">Gilberto Almeida <div>Instituto de Biofísica e Engenharia Biomédica<br>Faculdade de Ciências da Universidade de Lisboa<br>Campo Grande<br>1749-016 Lisboa, Portugal</div></font></span><br><br> <br></span></div></div><br> </blockquote></div><br>