Seriously, that snow mask doesn't make any sense... Obj world pos clamped to 0.5-0.5.. Which means you could've just used constant 0.5. Dot normalmap or [0,0,1] with [0,0,1] transformed to world space, then multiply/raise exponent depending on how hard falloff you want.
Well, it still doesn't make any sense. Do you know what the object world pos is? Right now you you just darken the snow mask and the snow mask is completely black at X=0 Y=0 Z=0. You have your snow direction parameter already transformed to world space (I suppose/hope), just dot it with your rock normalmap if you have one,…