To Smooth a Surface Using the Natural Neighbor Interpolation (NNI) Method
In Toolspace, on the Prospector tab, expand the surface Definition collection, right-click , and click Smooth Surface.
In the Smooth Surface dialog box, for the Select Method property, select Natural Neighbor Interpolation.
In Point Interpolation/Extrapolation Output, select the one of the Output locations: Grid Based, Centroids, Random Points, or Edge Midpoints. For more information, see
Depending on the location you selected, specify values:
Grid Based: Specify values for the output regions, grid spacing, and grid orientation properties.
Centroids: Specify the value for the output region.
Random Points: Specify the value for the output region.
Edge Midpoints: Select the triangle edges. Requires that surface triangles be displayed.