Awesome! I had been working on a similar project couldn't figure out the snow on the trees for the life of me! It's great to see how you approached it. The work look great! Thanks for sharing your process.
I believe author would be surprised that it's not american, but soviet bunker :)
Facial Rigging Balancing Quality & Control Part 2 of 7
Part 2 of this webinar discusses the potential problems of creating facial rigs and gives tips to aspiring animators and rigers.