doc/salome/gui/SMESH/files/smoothing.htm

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  88 <h1>Smoothing</h1>
  89
  90 <p><img src="../i_blue.jpg" x-maintain-ratio="TRUE" width="30px" height="30px" border="0" class="img_whs1"> Smoothing is used to adjust the locations of element
  91  corners (nodes) to reduce distortions in these elements.</p>
  92
  93 <p>&nbsp;</p>
  94
  95 <p class=TODO>To apply smoothing to the elements of your mesh:</p>
  96
  97 <p>&nbsp;</p>
  98
  99 <p class="whs2">1. Display a mesh or a submesh in the 3D
 100  viewer.</p>
 101
 102 <p class="whs2">2. In the <span style="font-weight: bold;"><B>Modification
 103  </B></span>menu select the <span style="font-weight: bold;"><B>Smoothing </B></span>item
 104  or click <img src="../image84.gif" width="24px" height="25px" border="0" class="img_whs3"> button in the toolbar. The <span style="margin-left: 40px;">dialog
 105  box contains the following fields which should be specified:</span></p>
 106
 107 <p>&nbsp;</p>
 108
 109 <p class="whs2"><img src="../pics/smoothing.png" x-maintain-ratio="TRUE" width="332px" height="396px" border="0" class="img_whs4"> &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</p>
 110
 111 <ul type="disc" class="whs5">
 112
 113         <li class=kadov-p><p class="whs6"><span
 114  style="font-weight: bold;"><B>Id Elements </B></span>field allows to specify
 115  the elements which should be smoothed by selecting them in the 3D viewer
 116  (lock <span style="font-weight: bold;"><B>Shift </B></span>button to select several
 117  elements).</p></li>
 118
 119         <ul type="disc" class="whs5">
 120
 121                 <li class=kadov-p><p class="whs7">Select whole mesh,
 122  submesh or group - <span style="font-weight: normal;">smoothing is applied
 123  to the whole mesh or its part.</span></p></li>
 124
 125                 <li class=kadov-p><p><span style="font-weight: bold;"><B>Fixed nodes
 126  ids</B></span>: some nodes keep their location during smoothing. If a mesh
 127  is built on a geometry shape, the nodes built on geometrical edges are
 128  always fixed. If smoothing is applied to a part of a mesh then the boundary
 129  nodes of an elements set are also fixed. Any other nodes may be additionally
 130  fixed.</p></li>
 131
 132                 <li class=kadov-p><p><span style="font-weight: bold;"><B>Smoothing
 133  Method</B></span>:</p></li>
 134
 135                 <ul type="disc" class="whs5">
 136
 137                         <li class=kadov-p><p><span style="font-weight: bold;"><B>Laplacian</B></span>
 138  smoothing pulls a node toward the center of surrounding nodes directly
 139  connected to that node along an element edge. Centroidal smoothing pulls
 140  a node toward the element-area-weighted centroid of the surrounding elements.
 141  Typically, the Laplacian method will produce the mesh with the least element
 142  distortion. It is also the faster method. </p></li>
 143
 144                         <li class=kadov-p><p><span style="font-weight: bold;"><B>Centroidal</B></span>
 145  smoothing usually produces a mesh that has more uniform element sizes.
 146  Both methods produce good results with &quot;free&quot; meshes.</p></li>
 147                 </ul>
 148         </ul>
 149 </ul>
 150
 151 <p>&nbsp;</p>
 152
 153 <p class="whs8"><img src="../image83.gif" width="527px" height="281px" border="0" class="img_whs9"></p>
 154
 155 <ul type="disc" class="whs5">
 156
 157         <li class=kadov-p><p class="whs6"><span
 158  style="font-weight: bold;"><B>Iteration limit: </B></span>both of the smoothing
 159  methods use an iterative procedure to converge toward a smoothed mesh.
 160  All nodes are smoothed according to one of the techniques shown above.
 161  Then the smoothing is reevaluated with the updated nodal locations. This
 162  process continues until the maximum number of iterations has been exceeded,
 163  or all elements has aspect ratio less or equal than the specified one.</p></li>
 164
 165         <li class=kadov-p><p class="whs6"><span
 166  style="font-weight: bold;"><B>Max. aspect ratio</B></span>.</p></li>
 167 </ul>
 168
 169 <p class="whs2">&nbsp;</p>
 170
 171 <p class="whs2">3. Click the <span style="font-weight: bold;"><B>Apply
 172  </B></span>or <span style="font-weight: bold;"><B>OK </B></span>button to confirm
 173  the operation.</p>
 174
 175 <p class="whs2">&nbsp;</p>
 176
 177 <p class="whs2"><img src="../pics/smoothing1.png" x-maintain-ratio="TRUE" width="353px" height="235px" border="0" class="img_whs10"> &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<img src="../pics/smoothing2.png" x-maintain-ratio="TRUE" width="351px" height="235px" border="0" class="img_whs11"></p>
 178
 179 <p>&nbsp;</p>
 180
 181 <p>&nbsp;&nbsp;<span style="font-weight: bold;"><B>See
 182  Also</B></span> a sample TUI Script of a <a href="../modifying_meshes.htm#bookmark8">Smoothing</a>
 183  operation. &nbsp;</p>
 184
 185 <p>&nbsp;</p>
 186
 187 <p>&nbsp;</p>
 188
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