This is an awesome idea. Not only "let's just use the 3dsmax DirectX shader pipeline", but the whole Unity3D surface shader approach. Thanks for the template.
There is a giant beast around ! #unity3d #madewithunity #screenshotsaturday #gamedev #indiedev #indiegame pic.twitter.com/KN9WORR34d — EATMEAT Games (@EATMEATGames) January 14, 2017
You would need to write or replace built-in shader, it is same procedure as with replacing foliage or terrain shaders. Google for Unity3D built-in shaders.