PolySmoother is a professional tool to efficiently work with Smoothing Groups.
It allows you to visualize and manage the Smoothing Groups in a quick and easy way.
You can set Hard and Soft edges, select edges by convexity, copy, paste, modify and optimize Smoothing Groups, as well as convert them from and to UV mapping, among many other features.
http://www.scriptspot.com/3ds-max/scripts/polysmoother
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