To see how the lighting, skinning and movement would work I created a extremely quick test of the moving tree branch. I used a cone as the tree branch and simply added bones and a skin modifier to it. There is also very simple lights to demonstrate how it might look. However I expect the final product to look different (and much better) as we are using the lighting within Unity.
Please note that, as this is just a test, I have not adjusted or fixed the smoothing groups, skinning or lights and used basic render settings.