NSMOOTH, NPASS
Smooths selected nodes among selected elements.
Repositions each selected node at the average position of its immediate
neighbors on the selected elements. The node positions converge after some
number of smoothing passes. For some initial conditions, NPASS
may
need to be much larger than 3. If the boundary of a mesh is to be undisturbed
(usually desirable), the boundary nodes should be unselected before issuing NSMOOTH.