<?xml version='1.0' encoding='UTF-8' ?>
<!DOCTYPE html
  SYSTEM "about:legacy-compat">
<html xmlns:mml = "http://www.w3.org/1998/Math/MathML" lang = "en"><head><meta charset = "UTF-8"/><meta name = "copyright" content = "(C) Copyright 2020"/><meta name = "DC.rights.owner" content = "(C) Copyright 2020"/><meta name = "DC.type" content = "concept"/><meta name = "abstract" content = "Use a design variable filter to control the smoothness of design nodes."/><meta name = "description" content = "Use a design variable filter to control the smoothness of design nodes."/><meta name = "DC.relation" scheme = "URI" content = "../TsoCmdMap/tso-r-cmd-dvconShape.htm#tso-r-cmd-dvconShape"/><meta name = "DC.format" content = "HTML5"/><meta name = "DC.identifier" content = "tso-c-usr-shape-desArea-dvcFilter"/><meta name = "DC.language" content = "en"/><link rel = "stylesheet" type = "text/css" href = "../DSDocUI_XML34.css"/><title>Filter Restriction (CHECK_TYPE=FILTER)</title>
<script type = "text/javascript" src = "../DSDocUI_Highlight34.js">
  	/* */
  	</script></head><body onLoad = "highlightSearchTerms();" id = "tso-c-usr-shape-desArea-dvcFilter">
<a name = "hj-top"> </a><table class = "table1" id = "table11"><tr><td><table class = "DocHeader"><tr><td class = "DocHeader1" colspan = "2"><h1>Filter Restriction (CHECK_TYPE=FILTER)</h1></td></tr><tr><td class = "DocHeader4" colspan = "2"/></tr><tr><td class = "DocHeader3"><table class = "DocHeaderIntro" id = "table12"><tr><td class = "Intro1Only"><p class = "header"><p class = "abstract">
<span class = "shortdesc">
	Use a design variable filter to control the smoothness of design nodes.
</span>

</p>

</p></td></tr></table></td><td class = "DocHeader2"><table class = "DocTopicsSeeAlso" id = "table13"><tr><td class = "TopicsTitle">See Also</td></tr></table><table class = "DocTopicsInOtherGuides" id = "table14"><tr><td height = "8px"/></tr><tr><td class = "TopicsTitleNormal">In Other Guides</td></tr><tr><td><a title = "Defines restrictions of the design variables in shape optimization." href = "../TsoCmdMap/tso-r-cmd-dvconShape.htm#tso-r-cmd-dvconShape">DVCON_SHAPE</a></td></tr></table></td></tr></table>




<div class = "body conbody">

<p>
<table class = "table" id = "tso-c-usr-shape-desArea-dvcFilter__table_4F6C511122C54899813D096F7385CD42"><caption/><colgroup><col style = "width:33.33333333333333%"/><col style = "width:33.33333333333333%"/><col style = "width:33.33333333333333%"/></colgroup><thead class = "thead">
<tr class = "row">
<th class = "entry" id = "tso-c-usr-shape-desArea-dvcFilter__table_4F6C511122C54899813D096F7385CD42__entry__1">Applicable for</th>
<th class = "entry align-center" id = "tso-c-usr-shape-desArea-dvcFilter__table_4F6C511122C54899813D096F7385CD42__entry__2">Controller (SHAPE_CONTROLLER)</th>
<th class = "entry align-center" id = "tso-c-usr-shape-desArea-dvcFilter__table_4F6C511122C54899813D096F7385CD42__entry__3">Sensitivity (SHAPE_SENSITIVITY)</th>
</tr>
</thead><tbody class = "tbody">
<tr class = "row">
<td class = "entry" headers = "tso-c-usr-shape-desArea-dvcFilter__table_4F6C511122C54899813D096F7385CD42__entry__1">CHECK_TYPE = FILTER</td>
<td class = "entry align-center" headers = "tso-c-usr-shape-desArea-dvcFilter__table_4F6C511122C54899813D096F7385CD42__entry__2">-</td>
<td class = "entry align-center" headers = "tso-c-usr-shape-desArea-dvcFilter__table_4F6C511122C54899813D096F7385CD42__entry__3">OK</td>
</tr>
</tbody></table>
</p>

<p>
    Use a design variable filter to smear out design node kinks.
    The configuration with groups allows fine granular
    control over different areas by choosing different filter radii or
    ensuring that certain areas do not interfere.
</p>

<p>A filter restriction is activated by setting the check type (<code class = "ph codeph">CHECK_TYPE</code>)
of the design variable constraint to <code class = "ph codeph">FILTER</code>.
The restriction is defined by the following parameters:
<ul class = "ul">
<li class = "li"><code class = "ph codeph">ND_GROUP</code>: The group of node for which the constraint is active.
     Defining a node group is mandatory.</li>
<li class = "li"><code class = "ph codeph">CHECK_GROUP</code>: The group of node that will be used in the internal check
    if nodes are properly supported and taken into account.
    ND_GROUP will be used if this parameter is not used.</li>

<li class = "li"><code class = "ph codeph">RADIUS</code>: Defines the filter radius in terms of value and whether absolute or relative units are used.
    If omitted, double the average edge length of the model is used.</li>
</ul>
</p>
<p>The parameter file command might look like the following:</p>
<pre class = "codeblock">
<code class = "ph codeph">
DVCON_SHAPE
  ID_NAME     = MY_DVCON_BEAD
  ND_GROUP    = ALL_NODES
  CHECK_TYPE  = FILTER
  CHECK_GROUP = ALL_NODES
  RADIUS      = 3.0, REL
END_
</code>
</pre>
<p>

<div class = "note"><span class = "run-in.note">Note:
			</span><span class = "notecontent">
<ul class = "ul">
    <li class = "li">The configuration with groups allows for fine granular control and is especially
    important if different design areas must not interfere.</li>
    <li class = "li">The mechanism used for this kind of filter differs from the default mechanism,
    which tends to lead to a better optimization convergence behavior in many cases.</li>
</ul>
</span></div>

<table class = "Remark" id = "table132"><tr><td class = "Remark"><span class = "run-in.important">Important:
				</span><span class = "notecontent">
<ul class = "ul">
<li class = "li">The filter restriction can only be used in combination with the sensitivity-based shape optimization approach.</li>
<li class = "li">When a filter restriction is used during the optimization, the default filtering (usually set in <code class = "ph codeph">OPT_PARAM</code>) is deactivated.</li>
</ul>
</span></td></tr></table>

</p>

</div>

<div class = "related-links"/></td></tr></table><script type = "text/javascript" src = "../DSDocUI_Bottom34.js">/* */</script></body>
</html>
