5 Blended Material through RGB Color ID Textures. issue

Hi.
I've created a Blended Material through a new shader (based on Snow example). I've succeed on making this one except that i can't find the way to offset the minimum angle where the snow start to appear. Tried to use a contrast node or Offset, but i could find the way. ( searching for some sort of level node like in SubDesigner).
Anyway the main Problem i got, is that if i want to Blend with that result more textures, for ground, through an RGB Texture to add 3 more different pass, it seems that Unity can't mix more than 2 Normal Map.
Clending the SideStoneWall and Top Stone is ok. but after that, using Lerp to mix the others, they didn't shade correctly ( same thing occur on AO pass)




i hope someone can help me. Cheers.
I've created a Blended Material through a new shader (based on Snow example). I've succeed on making this one except that i can't find the way to offset the minimum angle where the snow start to appear. Tried to use a contrast node or Offset, but i could find the way. ( searching for some sort of level node like in SubDesigner).
Anyway the main Problem i got, is that if i want to Blend with that result more textures, for ground, through an RGB Texture to add 3 more different pass, it seems that Unity can't mix more than 2 Normal Map.
Clending the SideStoneWall and Top Stone is ok. but after that, using Lerp to mix the others, they didn't shade correctly ( same thing occur on AO pass)




i hope someone can help me. Cheers.