<html dir="ltr"><head> <meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1"> <meta content="MSHTML 6.00.6000.21366" name="GENERATOR"> <style id="owaTempEditStyle"></style><style title="owaParaStyle"></style> </head> <body ocsi="x"> <div style="FONT-SIZE: x-small; COLOR: #000000; DIRECTION: ltr; FONT-FAMILY: Tahoma"> <div><font face="tahoma"> <div>Hi David and Simon, </div> </font></div> <div><font face="tahoma"><a></a><font face="tahoma">Thanks</font> for your<a></a> answers<a></a>, </font></div> <div><font face="tahoma"></font> </div> <div><font face="tahoma">The tree<a></a> structure (and what<a></a> I see<a></a>) makes<a></a> your<a></a> second rules<a></a> quite<a></a> likely<a></a>, </font></div> <div><font face="tahoma">but I keep<a></a> in mind<a></a> that<a></a> the behavior<a></a> is<a></a> not trustable<a></a>, and I make<a></a> sure to avoid<a></a> crossing<a></a> volumes when<a></a> doing<a></a> more tests (However<a></a> the crossing<a></a> volume approximation seems<a></a> to be<a></a> a good first-order<a></a> description of a weaving<a></a>). But I do have voxelised<a></a> and segmented<a></a> images of the geometry<a></a>. and switching<a></a> to a voxelised<a></a> geometry<a></a> is<a></a> on my<a></a> short-term<a></a> roadmap<a></a>. </font></div> <div><font face="tahoma"></font> </div> <div><font face="tahoma"><a></a><font face="tahoma">Cheers</font>, </font></div> <div><font face="tahoma">Maximilien </font></div> <div><font face="tahoma"></font> </div> <div id="divRpF526494" style="DIRECTION: ltr"> <hr tabindex="-1"> <font face="Tahoma" color="#000000" size="2"><b>De :</b> Simon Stute [gate.stute@gmail.com]<br> <b>Date d'envoi :</b> jeudi 27 février 2014 17:17<br> <b>À :</b> David Sarrut<br> <b>Cc :</b> MELISSAS Maximilien (SAFRAN); gate-users@lists.opengatecollaboration.org<br> <b>Objet :</b> Re: [Gate-users] Brothers volumes at the same position what's occuring<br> </font><br> </div> <div></div> <div> <div dir="ltr"> <div dir="ltr"> <div> <div> <div> <div>Hi,<br> <br> David is right, there should not be overlapping volumes, but still I think we can predict what happens ;-)<br> </div> <br> </div> The first rule is that the particle will be in the first volume it crosses. If it continues its way in this volume while passing through an overlapping volume, it will ignore the overlapping volume until it exits the first volume (because G4 uses DistanceToIn and DistanceToOut strategies to compute the way in/out through the different volumes).<br> <br> </div> The second rule is (I don't know it but I deduce it from your experiment), if it crosses 2 (or more) volumes at a same place while being in another volume, it will enter the last declared volume, because volumes in G4 are organised as a tree, and I can imagine that when scanning the tree, the program always does it in the same way (so here probably by starting with the last volume).<br> <br> </div> Still, be careful with overlapping volumes !<br> <br> Cheers,<br> Simon<br> </div> <br> </div> <div class="gmail_extra"><br> <br> <div class="gmail_quote">On Thu, Feb 27, 2014 at 5:06 PM, David Sarrut <span dir="ltr"> <<a href="mailto:David.Sarrut@creatis.insa-lyon.fr">David.Sarrut@creatis.insa-lyon.fr</a>></span> wrote:<br> <blockquote class="gmail_quote" style="PADDING-LEFT: 1ex; MARGIN: 0px 0px 0px 0.8ex; BORDER-LEFT: #ccc 1px solid"> <div><font size="+0"><span>Hello,</span></font></div> <div><font size="+0"><span><br> </span></font></div> <div><font size="+0"><span>In G4 (thus in gate), you could *not* have overlapping volumes. If some volumes overlap, the result is undefined. To my knowledge, you don't have the choice, you need to change your geometry.</span></font></div> <div><font size="+0"><span><br> </span></font></div> <div><font size="+0"><span>There is a feature in G4 to deal with overlapping volumes (called parallel world), but it is not available through gate.</span></font></div> <div><font size="+0"><span><br> </span></font></div> <div><font size="+0"><span>Sincerely,<br> David</span></font></div> <br> Le jeudi 27 février 2014, MELISSAS Maximilien (SAFRAN) <<a href="mailto:maximilien.melissas-alten@safran.fr">maximilien.melissas-alten@safran.fr</a>> a écrit : <div class="HOEnZb"> <div class="h5"><br> <blockquote class="gmail_quote" style="PADDING-LEFT: 1ex; MARGIN: 0px 0px 0px 0.8ex; BORDER-LEFT: #ccc 1px solid"> <div> <div style="FONT-SIZE: x-small; DIRECTION: ltr; FONT-FAMILY: Tahoma"> <div><a></a>Dear Gaters<a></a>, </div> <div><font face="tahoma"></font> </div> <div><font face="tahoma">A question related<a></a> to my<a></a> question from<a></a> yesterday<a></a>, </font></div> <div><font face="tahoma"><a></a><font face="tahoma">When</font> 2 brothers<a></a> volume are crossing<a></a>, what's<a></a> happening at<a></a> the crossing<a></a> point. </font></div> <div><font face="tahoma"><a></a><font face="tahoma">Here</font> is<a></a> a quick example<a></a> of what<a></a> I mean<a></a>, with<a></a> a mother<a></a> box having<a></a> 2 daughters<a></a> volume Castor and Pollux<a></a></font></div> <div><font face="tahoma"> <div><font face="tahoma">/gate<a></a>/motherbox<a></a>/daughters<a></a>/name<a></a> Castor </font></div> <div><font face="tahoma">/gate<a></a>/motherbox<a></a>/daughters<a></a>/insert cylinder<a></a></font><font face="Tahoma" color="#000000"><br> /gate<a></a>/Castor/geometry<a></a>/setHeight<a></a> 20. mm<br> /gate<a></a>/Castor/geometry<a></a>/setRmin<a></a> 0. mm<br> /gate<a></a>/Castor/geometry<a></a>/setRmax<a></a> 5. mm</font></div> <div><font face="tahoma">/gate<a></a>/Castor/placement/setTranslation<a></a> +2. -0. 0. mm</font></div> <div><font face="tahoma"></font> </div> </font></div> <div><font face="tahoma">/gate<a></a>/motherbox<a></a>/daughters<a></a>/name<a></a> Pollux<a></a></font></div> <div><font face="tahoma">/gate<a></a>/motherbox<a></a>/daughters<a></a>/insert cylinder<a></a></font><font face="Tahoma" color="#000000"><br> /gate<a></a>/Pollux<a></a>/geometry<a></a>/setHeight<a></a> 20. mm<br> /gate<a></a>/Pollux<a></a>/geometry<a></a>/setRmin<a></a> 0. mm<br> /gate<a></a>/Pollux<a></a>/geometry<a></a>/setRmax<a></a> 5. mm</font></div> <div><font face="tahoma">/gate<a></a>/Pollux<a></a>/placement/setTranslation<a></a> -2. -0. 0. mm</font></div> <div><font face="tahoma"></font> </div> <div><font face="tahoma"><a></a><font face="tahoma">these</font> volumes should<a></a> have a big<a></a> overlap<a></a> at<a></a> the center of motherbox<a></a>. </font></div> <div><font face="tahoma"></font> </div> <div><font face="tahoma"><a></a><font face="tahoma">Now</font> what's<a></a> occuring<a></a> when<a></a> a particle<a></a> pass<a></a> through<a></a> the middle of motherbox<a></a> ? </font></div> <div><font face="tahoma">Is the particle<a></a> inside<a></a> of Pollux<a></a> ? </font> </div> <div><font face="tahoma">Is the particle<a></a> inside<a></a> of Pollux<a></a> and Castor, and can<a></a> interact<a></a> with<a></a> both<a></a> </font></div> <div><font face="tahoma"><a></a><font face="tahoma">Does</font> the particle<a></a> belong<a></a> to the first volume it<a></a> crossed<a></a> ?</font></div> <div><font face="tahoma"></font> </div> <div><font face="tahoma"></font> </div> <div><font face="tahoma">If the last the volume always<a></a> on-top ? If yes<a></a>, this<a></a> answers<a></a> my<a></a> question from<a></a> yesterday<a></a>, </font></div> <div><font face="tahoma">the later-declared<a></a> volume being<a></a> on-top photons spend<a></a> more time inside<a></a> this<a></a> one and thus<a></a> scatter<a></a> more from<a></a> the last one. </font></div> <div><font face="tahoma"></font> </div> <div><font face="tahoma"><a></a><font face="tahoma">Cheers</font>, </font></div> <div><font face="tahoma">Maximilien </font></div> <div> </div> <div style="DIRECTION: ltr"> <hr> <div><font face="Tahoma" size="2"> <p> </p> <p>Maximilien MELISSAS<a></a></p> <p>Consultant, Alten<a></a> technology<a></a></p> <p>Image processing for CT NDT<a></a> @ Safran composite</p> <p>http://www.alten.com</p> </font></div> </div> </div> </div> </blockquote> </div> </div> </blockquote> </div> </div> </div> </div> <p>#<br> " Ce courriel et les documents qui lui sont joints peuvent contenir des informations confidentielles, être soumis aux règlementations relatives au contrôle des exportations ou ayant un caractère privé. 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