I am trying to make a roller coaster. I started with making a single piece of track, then added an Array Modifier, then Curve Modifier (where my curve was a simple NURBS curve).
Now, wanted to add a nice spiral to the curve, so created a separate spiral (using special curves add on), converted the spline format to Nurbs, and then merged it to my original curve (by Alt + J).
As soon as I do that, the curve modifier stops working on my rail track and the track just forms straight line (as if with only the array modifier and no curve modifier).
I tried this with simple examples and this always happens. Whenever you add a curve to your current curve, the curve modifier stops working. Any help on this please ?
Here is the file in case needed https://drive.google.com/file/d/1Mq1H64ShBL2adKhVeDP2mN5fVZcHl-4i/view?usp=sharing