1 <!doctype HTML public "-//W3C//DTD HTML 4.0 Frameset//EN">
6 <title>Sewing meshes</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">
11 if (navigator.appName !="Netscape")
12 { document.write("<link rel='stylesheet' href='../default.css'>");}
15 <style type="text/css">
17 img_whs1 { border:none; width:30px; height:30px; float:none; border-style:none; }
18 ul.whs2 { list-style:disc; }
19 p.whs3 { font-weight:bold; }
20 p.whs4 { margin-left:40px; }
21 img_whs5 { border:none; width:332px; height:548px; border-style:none; float:right; }
22 img_whs6 { border:none; width:612px; height:225px; border-style:none; }
23 img_whs7 { border:none; width:581px; height:218px; border-style:none; float:left; }
24 img_whs8 { border:none; width:600px; height:227px; border-style:none; }
25 p.whs9 { margin-left:0px; }
26 img_whs10 { border:none; width:620px; height:228px; border-style:none; }
27 img_whs11 { border:none; width:304px; height:222px; border-style:none; }
29 </style><script type="text/javascript" language="JavaScript">
31 if ((navigator.appName == "Netscape") && (parseInt(navigator.appVersion) == 4))
33 var strNSS = "<style type='text/css'>";
34 strNSS += "p.whs9 {margin-left:1pt; }";
36 document.write(strNSS);
40 <script type="text/javascript" language="JavaScript" title="WebHelpInlineScript">
43 if (innerWidth != origWidth || innerHeight != origHeight)
46 if ((parseInt(navigator.appVersion) == 4) && (navigator.appName == "Netscape")) {
47 origWidth = innerWidth;
48 origHeight = innerHeight;
54 <style type="text/css">
56 div.WebHelpPopupMenu { position:absolute; left:0px; top:0px; z-index:4; visibility:hidden; }
57 p.WebHelpNavBar { text-align:right; }
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">
68 if (window.setRelStartPage)
70 addTocInfo("MESH module\nModifying meshes\nTransforming meshes\nSewing meshes");
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");
77 if (window.setRelStartPage)
79 setRelStartPage("../index.htm");
89 document.location.reload();
93 <body><script type="text/javascript" language="javascript1.2">
95 if (window.writeIntopicBar)
99 <h1>Sewing meshes</h1>
101 <p><img src="../i_blue.jpg" x-maintain-ratio="TRUE" width="30px" height="30px" border="0" class="img_whs1"> In SMESH you can sew elements of different
102 meshes. The current functionality allows you to sew:</p>
106 <ul type="disc" class="whs2">
108 <li class=kadov-p><p class="whs3"><a href="#free bord">Free
109 borders </a></p></li>
111 <li class=kadov-p><p class="whs3"><a href="#conform">Conform
112 free borders</a></p></li>
114 <li class=kadov-p><p class="whs3"><a href="#border to side">Border
117 <li class=kadov-p><p class="whs3"><a href="#side elements">Side
118 elements</a></p></li>
121 <p class="whs3"> </p>
123 <p class=TODO>To sew elements of different meshes:</p>
125 <p class=TODO> </p>
127 <p class="whs4">1. From the <span style="font-weight: bold;"><B>Modification
128 </B></span>menu choose the <span style="font-weight: bold;"><B>Transformation
129 </B></span>item and from
130 its sub-menu select the <span style="font-weight: bold;"><B>Sewing </B></span>item.
133 <p class="whs4">2. Check in the dialog box one of the radio
134 buttons corresponding to the type of sewing operation you would like to
137 <p class="whs4">3. Fill the other fields available in the
140 <p class="whs4">4. Click the <span style="font-weight: bold;"><B>OK
141 </B></span><span>or </span><span style="font-weight: bold;"><B>Apply </B></span>button
142 to perform the operation of sewing. </p>
144 <h3><a name="free bord"></a>Sew free borders<img src="../pics/sewing1.png" x-maintain-ratio="TRUE" width="332px" height="548px" align="right" border="0" class="img_whs5"></h3>
146 <p>This functionality allows you to unite two free borders of a 2D mesh.</p>
150 <p>For sewing free borders you should define three points on each border:
151 first, second and the last node: </p>
155 <ul type="disc" class="whs2">
157 <li class=kadov-p><p> the
158 first node specifies beginning of the border ;</p></li>
160 <li class=kadov-p><p> the
161 second node specifies the part of the border which should be considered
162 (as far as the free border usually forms a closed contour);</p></li>
164 <li class=kadov-p><p> the
165 last node specifies the end of the border.</p></li>
170 <p>You can select these nodes in the 3D viewer or define by its id.</p>
174 <p>The first and the second nodes should belong to the same link of a face.
175 The second and the last nodes of a border can be the same. The first and
176 the last nodes of two borders can be the same. The corresponding end nodes
177 of two borders will be merged. Intermediate nodes of two borders will
178 be either merged or inserted into faces of the opposite border.</p>
182 <p>The sewing algorithm is as follows:</p>
186 <p class="whs4">1. The parameter (U) of each node within
187 a border is computed. So that the first node has U=0.0, the last node
188 has U=1.0, for the rest nodes 0.0 < U < 1.0;</p>
190 <p class="whs4">2. Compare node parameters of the two borders.
191 If two nodes of the opposite borders have close parameters, they are merged,
192 i.e. a node of the first border is replaced in all elements by a node
193 of the second border. If a node has no node with a close parameter in
194 the opposite border, it is inserted into an edge of element of the opposite
195 border, an element is split. Two nodes are considered close enough to
196 merge, if difference of their parameters is less than one fifth of minimum
197 length of adjacent face edges on the borders.</p>
201 <p class="whs4"><img src="../image22.jpg" width="612px" height="225px" border="0" class="img_whs6"></p>
203 <p class="whs4"> </p>
205 <p> <span style="font-weight: bold;"><B>See
206 Also</B></span> a sample TUI Script of a <a href="../transforming_meshes.htm#bookmark4">Sew
207 Free Borders</a> operation. </p>
211 <p class="whs4"> </p>
213 <h3><a name=conform></a>Sew conform free borders<img src="../pics/sewing2.png" x-maintain-ratio="TRUE" width="332px" height="548px" align="right" border="0" class="img_whs5"></h3>
215 <p>This functionality can be used to unite two free borders of a 2D mesh.
220 <p>The borders of meshes for sewing are defined as for "Sew free borders"
221 except that the second free border is not limited and can be defined by
222 the first and the second nodes only. The first nodes of two borders can
227 <p>The algorithm is following: counting nodes starting at the first ones,
228 the n-th node of the first border is merged with the n-th node of the
229 other border, until the end of either of borders. Nodes of the first border
230 are replaced in all elements with corresponding nodes of the second border.</p>
232 <p>For sewing conform free borders you should define three points on the
233 first border and two points on the second one. User can select these nodes
234 in 3D viewer or define node by its id.<img src="../image23.jpg" width="581px" height="218px" align="left" border="0" class="img_whs7"></p>
236 <p class="whs3"> </p>
238 <p class="whs3"> </p>
250 <p> <span style="font-weight: bold;"><B>See
251 Also</B></span> a sample TUI Script of a <a href="../transforming_meshes.htm#bookmark5">Sew
252 Conform Free Borders</a> operation. </p>
258 <h3><a name="border to side"></a>Sew border to side<img src="../pics/sewing3.png" x-maintain-ratio="TRUE" width="332px" height="548px" align="right" border="0" class="img_whs5"></h3>
260 <p>"Sew border to side" is intended to sew a free border to a
263 <p>The free border is defined as for "Sewing of free borders".
264 The place where to sew the border is defined by two nodes, between which
265 the border faces are placed, so that the first border node is merged with
266 the first node on the side and the last node of the border is merged with
267 the second specified node on the side.</p>
271 <p class="whs4"> </p>
273 <p>The algorithm is following.</p>
275 <p>1. Find a sequence of linked nodes on the side such that the found links
276 to be most co-directed with the links of the free border.</p>
278 <p>2. Sew two sequences of nodes using algorithm of "Sewing of free
281 <p>For sewing border to side you should define three points on the border
282 and two points on the side. User can select these nodes in 3D viewer or
283 define node by its id.</p>
285 <p><img src="../image30.jpg" width="600px" height="227px" border="0" class="img_whs8"></p>
287 <p> <span style="font-weight: bold;"><B>See
288 Also</B></span> a sample TUI Script of a <a href="../transforming_meshes.htm#bookmark6">Sew
289 Border to Side</a> operation. </p>
295 <h3><a name="side elements"></a>Sew side elements<img src="../pics/sewing4.png" x-maintain-ratio="TRUE" width="332px" height="548px" align="right" border="0" class="img_whs5"></h3>
297 <p class="whs9">This operation is intended to unite two mesh
300 <p class="whs9"> </p>
302 <p>Surfaces may be defined by either 2d or 3d elements. The number of given
303 elements of the sides must be the same. The sets of given elements must
304 be topologically equal, i.e. each node of one element set must have a
305 corresponding node in the other element set and corresponding nodes must
306 be equally linked. If there are 3d elements in a set, only their free
307 faces must obey to that rule.</p>
309 <p>Two corresponding nodes on each side must be specified. They must belong
310 to one element and must be located on an element set boundary.</p>
314 <p>Sewing algorithm finds and merges the corresponding nodes starting from
315 the specified ones.</p>
317 <p><img src="../image31.jpg" width="620px" height="228px" border="0" class="img_whs10"></p>
319 <p class="whs4"><img src="../image32.jpg" width="304px" height="222px" border="0" class="img_whs11"></p>
321 <p>For sewing side elements you should define elements for sewing and two
322 nodes for merging on the each side. User can select these elements and
323 nodes in 3D viewer or define them by its id.</p>
327 <p><span style="font-weight: bold;"><B>See Also</B></span> a sample TUI Script
328 of a <a href="../transforming_meshes.htm#bookmark7">Sew Side Elements</a>
329 operation. </p>
335 <script type="text/javascript" language="javascript1.2">
337 if (window.writeIntopicBar)