I encourage you to read through the thread in the UE4 forums, as I’ve already answered some interesting questions there and provided a little bit of insight.
A testversion of the snow can be downloaded here.
WIP Images and Videos (newest first):
Reworked almost every part of mask generation to be less clunky. Multiple material functions for easy modularity.
Usage demos with vertex color, adding an attribute to the system and changing the base material.
Tested material on a Landscape with tessellation:
(Result: Tessellation not good on Landscape, maybe try Parallax Occlusion Mapping)
Added slower melting in shadows based on vertex normal and mean sun direction:
First test of the snow with one of Epic’s Open World Demo materials as base:
Research on how to do snow sparkles without creating a custom shading model: