<ul>
<li>\b Name is the name of the mesh whose nodes will be merged.</li>
<li>\b Automatic or \b Manual mode allows choosing how the nodes are
-processed.
+ processed. In \b Manual mode you can adjust groups of coincident nodes
+ detected by the program and/or select any nodes to be merged.</li>
<li>\b Tolerance is a maximum distance between nodes sufficient for
merging.</li>
-<li><b>Exclude Groups</b> group box allows to ignore the nodes which
-belong to the specified mesh groups.
+<li>Activation of <b>No merge of corner and medium nodes of quadratic
+ cells</b> check-box prevents merging medium nodes of quadratic
+ elements with corner nodes. This check-box is enabled provided
+ that the selected mesh includes quadratic elements.</li>
+<li>Activation of <b>Avoid making holes</b> check-box prevents merging
+ nodes that make elements invalid (but not degenerated) and hence
+ removed. Thus, no holes in place of removed elements appear. </li>
+<li><b>Exclude groups from detection</b> group allows to ignore the
+ nodes which belong to the specified mesh groups. This control is
+ active provided that the mesh includes groups.</li>
+<li><b>Nodes to keep during the merge</b> group allows to specify
+ nodes to keep in the mesh. (By default a node being the first in a
+ group of coincident nodes is kept.) It is possible to either select
+ nodes in the Viewer or select groups of any element type whose nodes
+ will be kept.
+ <ul>
+ <li>\a Selection button activates selection of nodes to keep.</li>
+ <li><b>Nodes</b> button activates selection of nodes in the
+ Viewer.</li>
+ <li><b>Groups and sub-meshes</b> button activates selection of
+ groups and sub-meshes.</li>
+ <li>\b Add button adds selected nodes or groups to the list.</li>
+ <li> Nodes or groups selected in the list can be removed using \b
+ Remove button.</li>
+ </ul>
+</li>
</ul>
<li><b>Automatic mode:</b>
<br>
<ul>
-<li>In the \b Automatic Mode all Nodes within the indicated tolerance
-will be merged. The nodes which belong to the groups specified in the
-<b>Exclude Groups</b> will be not taken into account.</li>
+<li>In the \b Automatic Mode all nodes within the indicated tolerance
+will be merged. The nodes which belong to the groups specified in
+<b>Exclude groups from detection</b> will NOT be taken into account.</li>
</ul>
</li><br>
<li> The \b Manual mode gives you full control of what the operation will do.
In this mode additional controls are available:
<ul>
-<li>\b Detect button generates the list of coincident nodes for the given
-\b Tolerance.</li>
-<li><b>Coincident nodes</b> is a list of groups of nodes for
- merging. After the operation all nodes of each group will
- be united into one node. The first node of a group is kept and
- the others are removed.
+ <li>\b Detect button generates the list of coincident nodes for the given
+ \b Tolerance.</li>
+ <li><b>Coincident nodes</b> is a list of groups of nodes for
+ merging. Upon \b Apply all nodes of each group will
+ be united into one node. The first node of a group is kept and
+ the others are removed. By default the first node has a lowest ID
+ within the group.
<ul>
<li>\b Remove button deletes the selected group from the list.</li>
<li>\b Add button adds to the list a group of nodes selected in the
-viewer with pressed "Shift" key.</li>
+viewer.</li>
<li><b>Select all</b> check-box selects all groups.</li>
<li><b>Show double nodes IDs</b> check-box shows/hides identifiers of
nodes of selected groups in the 3D viewer.</li>
\image html mergenodes.png
<br>
</li>
-<li><b>Edit selected group</b> list allows editing the selected
- group:
- <br><br>
- \image html add.png
- <center>adds to the group the nodes selected in the viewer.</center>
- <br>
- \image html remove.png
- <center>removes from the group the selected nodes.</center>
- <br>
- \image html sort.png
- <center>moves the selected node to the first position in the
- group in order to keep it in the mesh.</center><br>
-</li>
+ <li><b>Edit selected group of coincident nodes</b> list allows
+ editing the selected group:
+ <br><br>
+ \image html add.png
+ <center>adds to the group the nodes selected in the viewer.</center>
+ <br>
+ \image html remove.png
+ <center>removes from the group the selected nodes.</center>
+ <br>
+ \image html sort.png
+ <center>moves the selected node to the first position in the
+ group in order to keep it in the mesh.</center><br>
+ </li>
</ul>
</li>
<li>To confirm your choice click \b Apply or <b>Apply and Close</b> button.</li>
</ol>
-\image html merging_nodes1.png "The initial object"
-
-\image html merging_nodes2.png "The object has been merged with a very big tolerance"
+\image html merging_nodes1.png
+<center> The initial object. Nodes 25, 26 and 5 are added to <b>Nodes
+ to keep during the merge</b> group.
+</center>
+<br>
+\image html merging_nodes2.png
+<center> The object has been merged
+</center>
<br><b>See Also</b> a sample TUI Script of a
\ref tui_merging_nodes "Merge Nodes" operation.