@rich o brien said:
I'd use the native Sandbox tools to drape your kerb rail onto the terrain.
https://i.imgur.com/upUhxFt.png
Extract the draped profile so you can create its surface then Stamp that.
Drape tool is useful but it is not necessarily suitable to the scenario I have encountered. To use the tool as you explained (many thanks for it), I still need to figure out the roads' detail heights manually before apply it onto a mountainous terrain.
The thing is if I have a terrain generated from contours and road plan which is totally flat, there is no way drape tool can put the road network correctly following the terrain, not the other way around.
I hope there is a tool which can stamp the road plan onto an uneven terrain while maintain/allow editing roads' surface.
Thanks again,