Virtual textures height blending into terrain question

Hi there, I just wanted to know how can I render a road for example into terrain with blending via height. I made a spline road(with 3 mats by vertex painted with height blend) thats projects on terrain using virtual texture material domain mode. But I wonder to know how should I blend it with height blending. My landscape has 9height blended layers and virtual texture pins output, it has world height input but I don’t know what should go in there and how I should use its output in my road material from vt sample. Any ideas?