[UE4] Procedural Foliage Seasons

Procedural system of dynamic change of seasons in Unreal Engine 4. Example scene is built of only three shaders for each type of objects: tree, grass and landscape.
Smooth change of seasons is done in a single shader via a common set of parameters controlled by Blueprint. The final appearance is adjusted by a set of parameters, like: fall color or snow weight. Each asset uses up to 4 textures: base color, normals and two mask textures (e.g. roughness, ao and extra masks used by the procedural system).
Of course, there are still a few things to improve. But it's good for a prototype.