How to fix Snow Shader error? Why is everything white? (¿raycast error?)

I’m trying to apply a snow shader to a landscape. I believe the snow shader is correct (followed this tutorial: https://www.youtube.com/watch?v=IC9g5hlfV6o), but for some reason, when applying it to the material, everything turns out to be white.

I reckon it’s because of the way I’m applying the shader, or there’s a missing raycast from above that would choose only the top layer of the objects. If true, how do I do that? If not, what should be the issue and how do I fix it?
I’m still a beginner here ^^’
(Every tutorial out there is now really outdated…)

Thanks in advance! :slight_smile: