TrainCarts lets us create Roller Coasters with special features like custom tracks, carts, and MORE!
TrainCarts was made for 1.12.2 (1.14 is broken).
Link: https://www.spigotmc.org/resources/traincarts.39592/
It does allow us to make 3D models too!
Anyone who is thinking on adding it, DM me, I can show you some stuff created with TrainCarts.