For faces that are significantly smaller or narrower than the desired local mesh element size, it is recommended to use Collapse Faces. It is also recommended to keep edges in sharp corners of importance to the result. When a composite face is meshed, all mesh vertices are located on the face, but there is no guarantee that there will be mesh vertices on the ignored edge. For example, ignoring an edge connected to two planar faces in a 90 degree angle, some of the created triangular elements may not coincide with any of the original faces, as shown below.

Tidying up a geometry to remove small and narrow faces gives the mesh algorithm more freedom to create a good quality mesh. An alternative is to use the Form Composite Faces and Collapse Faces operations. The Remove Details operation provides a fully automated way to find sliver faces, small faces and narrow face regions and uses, among others, the Ignore edges operation to form composite faces.

To use the operation, in the Geometry toolbar, from the Virtual Operations menu (), select Ignore Edges (). Then enter the properties of the operation using the following sections:

Select the edges that you want to ignore in the Graphics window. These then appear in the Edges to ignore list. If the geometry sequence includes user-defined selections above the Ignore Edges node, choose Manual to select edges, or choose one of the selection nodes from the list next to Edges to ignore.

Click the Active button to toggle between turning ON and OFF the Edges to ignore selections.

Use the Ignore adjacent vertices check box to also remove the ignorable start and end vertices of the edges.

Use the Keep input for mesh control check box to specify that the selected edges disappear from the geometry but become available when you build the mesh. You can, for example, use mesh control edges to control the element size inside a domain or to partition the geometry to use a mapped mesh. See also Mesh Control Edges.