Menu: Mesh->Edit mesh->Smooth elements
Currently only triangles, tetrahedra and hexahedra can be smoothed.
In the case of tetrahedra and hexahedra, element connectivity is preserved 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.