Edit mesh

Menu: Mesh->Edit mesh

This option lets you modify a mesh. All modifications will be lost when the mesh is generated again.

Move node

Menu: Mesh->Edit mesh->Move node

By using this command, an existing node is selected and moved. The new position is entered in the usual way (see Point definition ).

Split Elements

Menu: Mesh->Edit mesh->Split elements

To split elements, select them in the usual way (see Entity selection ), and then press escape (see Escape ) to perform the action. Triangles can be split into triangles, quadrilaterals into two or four triangles, tetrahedra into tetrahedra, hexahedra into tetrahedra, and prisms into tetrahedra.

When splitting triangles, the new nodes can be located in the mid-edge or with an enhanced interpolation (modified Butterfly scheme) in order to obtain a smooth mesh.

When splitting quadrilaterals, if 'SymmetricalStructuredTriangles' is set (see Preferences -> Meshing), then four triangles are generated for each quadrilateral; otherwise only two triangles are created per element.

When splitting hexahedra, if 'SymmetricalStructuredTetrahedra' is set (see Preferences -> Meshing) , then 24 tetrahedra are generated for each hexahedron; otherwise six tetrahedra are created per element.

If original elements are quadratic, the triangles or tetrahedra obtained are quadratic. Otherwise, if original elements are linear, the triangles or tetrahedra obtained are linear.

In the case of quadratic quadrilaterals, extra nodes are generated. These nodes are not associated with geometric entities, they have simply been obtained by interpolating mesh node coordinates.

In the case of hexahedra or prisms, all selected elements must be of the same quadratic type.

With triangles or tetrahedra, when selecting only a part of the mesh, neighbor elements will be also splitted to mantain a conformal mesh. For tetrahedra is not possible to split them if they are connected with neighbor elements of another element type (to avoid create non-conformal meshes)

Note: Currently, the operation Split triangles and tetrahedra only works for linear elements.

Smooth Elements

Menu: Mesh->Edit mesh->Smooth elements

To smooth elements, select them in the usual way (see Entity selection ), and then press escape (see Escape ) to perform the action.

Currently only triangles, tetrahedra and hexahedra can be smoothed.

In the case of tetrahedra and hexahedra, element connectivity is conserved after the smoothing; however, with triangle elements this may be modified during the smoothing process.

In case of triangles, sharp edges can be preserved in the smoothing process. User can set the maximum angle to be considered as sharp by the 'TolAngle' option in the contextual menu (Mouse operations ).

All selected elements must be of the same quadratic type.

Collapse

Menu: Mesh->Edit mesh->Collapse

The Collapse function converts coincident entities, i.e. entities that are close each other, into one.

It is possible to collapse edges, nodes, elements or the whole mesh.

Note: Entities belonging to a frozen layer (see Layers ) are not checked when collapsing.

Delete nodes or elements

Menu: Mesh->Edit mesh->Delete

To delete elements or nodes, select them in the usual way (see Entity selection ), and then press escape (see Escape ) to perform the action.

Nodes that no longer belong to any element after the operation are also erased.

Note: It is possible to filter the selection, e.g. to select only triangles but not quadrilaterals (see Selection window ).

Note: Only lonely nodes (nodes of the mesh that do not belong to any element) can be deleted.