I think it would have to be so that each node can be moved independently and the graphics of the spline should be something like a metal texture ? and so that this at least would be able to use in the editor and maybe even ingame ? I would make it both ways in editor and ingame if possible. If you could make this and it was a reasonable price I would surely buy it ! I would have no idea myself on how to go about doing this as I've only done that sort of thing in Unity and that was in C#. Also the idea of the whole system is to have the player be able to jump on and off the rails at any given time and that they could go both directions on the rails. I haven't bought UltraEngine yet but I would buy it right away if I had this sort of system with it. Reason why I haven't bought it yet is I don't see anything I can make with it yet. Does it have different templates like RPG, RTS, FPS, adventure, driving, etc.. to work from to make a game yet ? I only seen basic things like a 3rd person controller vid and that was about it.