Creating fake parallax using shells technique?

Hi all,

I’m trying to create a series of layered geometry, each with a tighter alpha to fake fur. You can see this in “The Shadow of the Colossus” and by Joost in the image below - and the rest of what I’m writing should make sense :).

I’m wondering if there is a way to optimise requiring 4 different alpha textures of tighter values, and instead clamping the one texture in the shader to get 4 (or ideally more) values.
Additionally instead of requiring offsetting the 4 sets of UVs within 0-1, offsetting them by 1 and have that readable in the shader. So I don’t require a new material for each of the 4 layers.

If anyone can offer any suggestions on whether this is achievable that would be great. I’d otherwise use POM but this is for iOS and I’m not sure it’s supported.

Thanks in advance.