So I took a little time to smooth out the spline, and learned something: check the output of the functions you use. I was getting an error that POV-Ray was trying to use an xyz vector as a uv vector, which it apparently does not like to do. I isolated two lines as the possible source of the problem, and noticed that they both referenced a variable I’d made using the vnormalize function, which outputs an xyz vector. So after I added a line to trim the vector down, it worked perfectly…
Well, it worked. It still took a bit of fiddling to get it just the way I wanted it.
What are all the little round things? Why are some of them different colors?
Those are the points that I was using to define the shape’s profile. It gets revolved around the vertical axis. I made those two spheres a different color to see which points were which. Since it doesn’t have a real-time 3D interface, sometimes I have to change colors or something to be able to tell which point is where.