Ok, perhaps I'm not explaining myself very well. I
don't mean changing or even touching the engine. I
don't mean complex physics simulations. I
don't mean dynamic cumulative snow buildup over the duration of the game. I
don't mean snowy textures. I
don't mean snow on trees and bushes.
When snow falls for an extended duration, it collects in heaps. Often these heaps become large and slide off things like eaves and railings. When this happens, you get collected mounds/ ridges of snow that line walls and pretty much everything else. These snow collections effectively change the surface from being (unrealistically) billiard table smooth into being lumpy, with a propensity towards mounds against walls.
Some simple snow textured low poly meshes lining appropriate walls/railings/fences will suffice. A lumpy ground surface would also be a nice asthetic addition. Things that can be done fairly easily in radiant. No coding. No mad physics. No engine changes. Nothing hard.
