It’s not possible. Landscape height isn’t stored as single big texture. So it can’t be possible to sample from arbitary position at material level. You could trace under object to get single component and get height texture from that. But even with this setup you get problems when object is at component seams. You could render landscape to render target where you store the depth and use that texture at material. If you don’t have too big landscape this might work quite well. If you have too big landscape then render just closest landscape components and rerender when camera shift too much.