<html xmlns:v="urn:schemas-microsoft-com:vml" xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns:m="http://schemas.microsoft.com/office/2004/12/omml" xmlns="http://www.w3.org/TR/REC-html40">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=us-ascii">
<meta name="Generator" content="Microsoft Word 15 (filtered medium)">
<style><!--
/* Font Definitions */
@font-face
        {font-family:"Cambria Math";
        panose-1:2 4 5 3 5 4 6 3 2 4;}
@font-face
        {font-family:Calibri;
        panose-1:2 15 5 2 2 2 4 3 2 4;}
@font-face
        {font-family:Consolas;
        panose-1:2 11 6 9 2 2 4 3 2 4;}
/* Style Definitions */
p.MsoNormal, li.MsoNormal, div.MsoNormal
        {margin:0cm;
        margin-bottom:.0001pt;
        font-size:11.0pt;
        font-family:"Calibri",sans-serif;}
a:link, span.MsoHyperlink
        {mso-style-priority:99;
        color:#0563C1;
        text-decoration:underline;}
a:visited, span.MsoHyperlinkFollowed
        {mso-style-priority:99;
        color:#954F72;
        text-decoration:underline;}
p
        {mso-style-priority:99;
        mso-margin-top-alt:auto;
        margin-right:0cm;
        mso-margin-bottom-alt:auto;
        margin-left:0cm;
        font-size:12.0pt;
        font-family:"Times New Roman",serif;}
code
        {mso-style-priority:99;
        font-family:"Courier New";}
pre
        {mso-style-priority:99;
        mso-style-link:"Preformattato HTML Carattere";
        margin:0cm;
        margin-bottom:.0001pt;
        font-size:10.0pt;
        font-family:"Courier New";}
span.PreformattatoHTMLCarattere
        {mso-style-name:"Preformattato HTML Carattere";
        mso-style-priority:99;
        mso-style-link:"Preformattato HTML";
        font-family:Consolas;}
p.msonormal0, li.msonormal0, div.msonormal0
        {mso-style-name:msonormal;
        mso-margin-top-alt:auto;
        margin-right:0cm;
        mso-margin-bottom-alt:auto;
        margin-left:0cm;
        font-size:12.0pt;
        font-family:"Times New Roman",serif;}
span.StileMessaggioDiPostaElettronica21
        {mso-style-type:personal;
        font-family:"Calibri",sans-serif;
        color:windowtext;}
p.HTMLPreformatted, li.HTMLPreformatted, div.HTMLPreformatted
        {mso-style-name:"HTML Preformatted";
        mso-style-link:"HTML Preformatted Char";
        margin:0cm;
        margin-bottom:.0001pt;
        font-size:11.0pt;
        font-family:"Calibri",sans-serif;}
span.HTMLPreformattedChar
        {mso-style-name:"HTML Preformatted Char";
        mso-style-priority:99;
        mso-style-link:"HTML Preformatted";
        font-family:"Courier New";}
span.StileMessaggioDiPostaElettronica25
        {mso-style-type:personal-reply;
        font-family:"Calibri",sans-serif;
        color:#1F497D;}
.MsoChpDefault
        {mso-style-type:export-only;
        font-size:10.0pt;}
@page WordSection1
        {size:612.0pt 792.0pt;
        margin:72.0pt 72.0pt 72.0pt 72.0pt;}
div.WordSection1
        {page:WordSection1;}
--></style><!--[if gte mso 9]><xml>
<o:shapedefaults v:ext="edit" spidmax="1026" />
</xml><![endif]--><!--[if gte mso 9]><xml>
<o:shapelayout v:ext="edit">
<o:idmap v:ext="edit" data="1" />
</o:shapelayout></xml><![endif]-->
</head>
<body lang="IT" link="#0563C1" vlink="#954F72">
<div class="WordSection1">
<p class="MsoNormal"><span style="color:#1F497D;mso-fareast-language:EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="color:#1F497D;mso-fareast-language:EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="color:#1F497D">In the attached Test_05.geo file (together with spline.geo and background.geo which are merged into it), I need to generate the Volume between the internal and external surfaces (which would be the
 difference between volumes 2 and 1, as defined in the file).<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="color:#1F497D">The problem is that, in the definition of the internal volume, gmsh sees its boundary surfaces as “embedded”, as can be seen from the attached screen.jpg. This is maintained when the new volume is
 generated, so that the “hole” is not obtained.<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="color:#1F497D">Somebody could please suggest how to work this out? Thank you!<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="color:#1F497D"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="color:#1F497D">Alessandro<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="color:#1F497D"><o:p></o:p></span></p>
</div>
</body>
</html>