You use the unreal engine instead. Hah, no I think sure there's a shader that does it in Unity 2018 using the HD render pipeline but I haven't tried it. I think for 2017 you would have to look on the asset store.
Not actual geometry like a mesh asset, it uses a displacement map with tessellation. Unity doesn't have this by default it only has parallax occlusion.
Thanks for the feedback, unfortunately reducing the thickness leads to clipping issues with the rocks. I'll have to leave it as is because I've already spent too much time on it.
