***Automatic** or **Manual** Mode allows choosing how the elements are processed. In the **Automatic** Mode all elements created on the same nodes will be merged. In **Manual** mode you can adjust groups of coincident elements detected by the program.
***Exclude groups from detection** group allows to ignore the elements which belong to the specified mesh groups. This control is active provided that the mesh includes groups.
***Elements to keep during the merge** group allows to specify elements to keep in the mesh. (By default an element being the first in a group of coincident elements is kept.) It is possible to either select elements in the Viewer or select groups whose elements will be kept.
**Selection* button activates selection of elements to keep.
***Elements** button activates selection of elements in the Viewer.
***Groups and sub-meshes** button activates selection of groups and sub-meshes.
***Add** button adds selected elements or groups to the list.
* Elements or groups selected in the list can be removed using **Remove** button.
***Detect** button generates the list of coincident elements found in the selected object.
***Coincident elements** is a list of groups of elements for merging. After the operation all elements of each group will be united into one element. The first element of a group is kept and the others are removed.
***Remove** button deletes the selected group from the list.
***Add** button adds to the list a group of elements selected in the viewer with pressed "Shift" key.
***Select all** check-box selects all groups.
***Show double elements IDs** check-box shows/hides identifiers of elements of the selected groups in the 3D viewer.
***Edit selected group of coincident elements** list allows editing the selected group:
In the following picture you see a triangle which coincides with one of the elements of the mesh. After we apply **Merge Elements** functionality, the triangle will be completely merged with the mesh.
