In shape optimization the surface of a component is modified.
If only the surface nodes are displaced and the inner nodes remain at
their location, the surface layer elements will be strongly distorted.
As a result, the quality of the FE calculation suffers and may no longer
form a reliable basis for the optimization. To ensure realistic and
high-quality results, a displacement of the surface usually necessitates
a mesh displacement (mesh smoothing) in the inner of the structure in
most cases.