doc/salome/gui/SMESH/aspect_ratio_3d.htm

   1 <!doctype HTML public "-//W3C//DTD HTML 4.0 Frameset//EN">
   2
   3 <html>
   4
   5 <head>
   6 <title>Aspect ratio 3D</title>
   7 <meta http-equiv="content-type" content="text/html; charset=windows-1252">
   8 <meta name="generator" content="RoboHelp by eHelp Corporation www.ehelp.com">
   9 <link rel="stylesheet" href="default_ns.css"><script type="text/javascript" language="JavaScript" title="WebHelpSplitCss">
  10 <!--
  11 if (navigator.appName !="Netscape")
  12 {   document.write("<link rel='stylesheet' href='default.css'>");}
  13 //-->
  14 </script>
  15 <style type="text/css">
  16 <!--
  17 img_whs1 { border:none; width:416px; height:385px; border-style:none; }
  18 img_whs2 { border:none; width:30px; height:30px; float:none; border-style:none; }
  19 ul.whs3 { list-style:disc; }
  20 img_whs4 { border:none; width:258px; height:246px; border-style:none; float:left; }
  21 img_whs5 { border:none; width:133px; height:56px; border-style:none; }
  22 img_whs6 { border:none; width:425px; height:192px; border-style:none; }
  23 img_whs7 { border:none; width:89px; height:32px; border-style:none; }
  24 img_whs8 { border:none; width:569px; height:386px; float:none; border-style:none; }
  25 p.whs9 { margin-left:40px; }
  26 img_whs10 { border:none; width:24px; height:26px; border-style:none; }
  27 p.whs11 { margin-left:0px; }
  28 -->
  29 </style><script type="text/javascript" language="JavaScript">
  30 <!--
  31 if ((navigator.appName == "Netscape") && (parseInt(navigator.appVersion) == 4))
  32 {
  33   var strNSS = "<style type='text/css'>";
  34   strNSS += "p.whs11 {margin-left:1pt; }";
  35   strNSS +="</style>";
  36   document.write(strNSS);
  37 }
  38 //-->
  39 </script>
  40 <script type="text/javascript" language="JavaScript" title="WebHelpInlineScript">
  41 <!--
  42 function reDo() {
  43   if (innerWidth != origWidth || innerHeight != origHeight)
  44      location.reload();
  45 }
  46 if ((parseInt(navigator.appVersion) == 4) && (navigator.appName == "Netscape")) {
  47         origWidth = innerWidth;
  48         origHeight = innerHeight;
  49         onresize = reDo;
  50 }
  51 onerror = null;
  52 //-->
  53 </script>
  54 <style type="text/css">
  55 <!--
  56 div.WebHelpPopupMenu { position:absolute; left:0px; top:0px; z-index:4; visibility:hidden; }
  57 p.WebHelpNavBar { text-align:right; }
  58 -->
  59 </style><script type="text/javascript" language="javascript1.2" src="whmsg.js"></script>
  60 <script type="text/javascript" language="javascript" src="whver.js"></script>
  61 <script type="text/javascript" language="javascript1.2" src="whproxy.js"></script>
  62 <script type="text/javascript" language="javascript1.2" src="whutils.js"></script>
  63 <script type="text/javascript" language="javascript1.2" src="whtopic.js"></script>
  64 <script type="text/javascript" language="javascript1.2">
  65 <!--
  66 if (window.gbWhTopic)
  67 {
  68         if (window.setRelStartPage)
  69         {
  70         addTocInfo("MESH module\nQuality controls\nAspect ratio 3D");
  71 addButton("show",BTN_IMG,"Show","","","","",0,0,"whd_show0.gif","whd_show2.gif","whd_show1.gif");
  72 addButton("hide",BTN_IMG,"Hide","","","","",0,0,"whd_hide0.gif","whd_hide2.gif","whd_hide1.gif");
  73
  74         }
  75
  76
  77         if (window.setRelStartPage)
  78         {
  79         setRelStartPage("index.htm");
  80
  81                 autoSync(1);
  82                 sendSyncInfo();
  83                 sendAveInfoOut();
  84         }
  85
  86 }
  87 else
  88         if (window.gbIE4)
  89                 document.location.reload();
  90 //-->
  91 </script>
  92 </head>
  93 <body><script type="text/javascript" language="javascript1.2">
  94 <!--
  95 if (window.writeIntopicBar)
  96         writeIntopicBar(4);
  97 //-->
  98 </script>
  99 <h1>Aspect ratio 3D</h1>
 100
 101 <p><img src="image86.jpg" width="416px" height="385px" border="0" class="img_whs1"></p>
 102
 103 <p>&nbsp;</p>
 104
 105 <p><img src="i_blue.jpg" x-maintain-ratio="TRUE" width="30px" height="30px" border="0" class="img_whs2"> The Aspect Ratio 3D mesh quality criterion calculates
 106  the same parameter as the <a href="files/aspect_ratio.htm">Aspect ratio</a>
 107  criterion, but it is applied to 3D mesh elements: tetrahedrons, pentahedrons,
 108  hexahedrons, etc. &nbsp;</p>
 109
 110 <p>&nbsp;</p>
 111
 112 <ul type="disc" class="whs3">
 113
 114         <li class=kadov-p><p><img src="image20.gif" width="258px" height="246px" align="left" border="0" class="img_whs4">The <span style="font-weight: bold;"><B>Aspect
 115  Ratio</B></span> of a <span style="font-weight: bold;"><B>tetrahedron</B></span>
 116  3D element is calculated by the formula:</p></li>
 117 </ul>
 118
 119 <p>&nbsp;</p>
 120
 121 <p>&nbsp;</p>
 122
 123 <p><img src="image19.gif" width="133px" height="56px" border="0" class="img_whs5">,</p>
 124
 125 <p>&nbsp;</p>
 126
 127 <p>where <span style="font-weight: bold; font-style: italic;"><I><B>S</B></I></span><span
 128  style="font-weight: bold;
 129                 font-style: italic;
 130                 vertical-align: Sub;"><I><B>K</B></I></span> is the sum of surfaces of the faces
 131  of &#1050; and <span style="font-weight: bold; font-style: italic;"><I><B>V</B></I></span><span
 132  style="vertical-align: Sub;
 133                 font-weight: bold;
 134                 font-style: italic;"><I><B>K</B></I></span> is the volume of &#1050; :</p>
 135
 136 <p>&nbsp;</p>
 137
 138 <p><img src="image18.gif" width="425px" height="192px" border="0" class="img_whs6">T</p>
 139
 140 <p>&nbsp;</p>
 141
 142 <ul type="disc" class="whs3">
 143
 144         <li class=kadov-p><p>Other element types like quadrangle, pentahedron
 145  and hexahedron use the following formula:</p></li>
 146 </ul>
 147
 148 <p><img src="image30.gif" width="89px" height="32px" border="0" class="img_whs7"> , where <span style="font-weight: bold; font-style: italic;"><I><B>Q</B></I></span><span
 149  style="vertical-align: Sub;
 150                 font-weight: bold;
 151                 font-style: italic;"><I><B>i</B></I></span> represents the value of <span style="font-weight: bold; font-style: italic;"><I><B>Q</B></I></span><span
 152  style="vertical-align: Sub;
 153                 font-weight: bold;
 154                 font-style: italic;"><I><B>k</B></I></span> for all possible simplexes (of the
 155  same dimension as the element) that compose the element.</p>
 156
 157 <p>For example, a hexahedron is split in 6 tetrahedrons, the <span style="font-weight: bold;"><B>Aspect
 158  ratio 3D</B></span> is calculated for each of them, then the greatest <span
 159  style="font-weight: bold; font-style: italic;"><I><B>Q</B></I></span><span style="vertical-align: Sub;
 160         font-weight: bold;
 161         font-style: italic;"><I><B>k</B></I></span> is considered to be the &nbsp;<span
 162  style="font-weight: bold;"><B>Aspect ratio 3D</B></span>
 163  criterion for the whole &nbsp;hexahedron.</p>
 164
 165 <p><img src="pics/image139.gif" x-maintain-ratio="TRUE" width="569px" height="386px" border="0" class="img_whs8"></p>
 166
 167 <p>&nbsp;</p>
 168
 169 <p class=TODO>To apply the Aspect Ratio 3D quality criterion to your mesh:</p>
 170
 171 <p class=TODO>&nbsp;</p>
 172
 173 <p class="whs9">1. Display your mesh in the viewer.</p>
 174
 175 <p class="whs9">&nbsp;</p>
 176
 177 <p class="whs9">2. Choose <span style="font-weight: bold;"><B>Controls
 178  &gt; Aspect Ratio 3D </B></span>or click <img src="image144.gif" width="24px" height="26px" border="0" class="img_whs10"> button of the toolbar.
 179  Your mesh will be displayed in the viewer with its elements colored according
 180  to the applied mesh quality control criterion:</p>
 181
 182 <p>&nbsp;</p>
 183
 184 <p class="whs11"><span style="font-weight: bold;"><B>See Also</B></span>
 185  a sample TUI Script of an <span style="font-weight: bold;"><B><a href="quality_controls.htm#bookmark11">Aspect
 186  Ratio 3D</B></span> quality control</a> operation. &nbsp;</p>
 187
 188 <p>&nbsp;</p>
 189
 190 <p>&nbsp;</p>
 191
 192 <p>&nbsp;</p>
 193
 194 <p>&nbsp;</p>
 195
 196 <script type="text/javascript" language="javascript1.2">
 197 <!--
 198 if (window.writeIntopicBar)
 199         writeIntopicBar(0);
 200 //-->
 201 </script>
 202 </body>
 203 </html>