Are the railings going behind, or close to, a foreground object or person?
If so, then you’ll probably ned to create a matte for the foreground person, and ALSO use points or splines (what AE calls masks). AE’s masks might be more appropriate here, because you can tell twixtor to track the whole length of the railing and not just one spot. This is because when the railings go out of view (or into view) it’s very difficult for Twixtor to figure out which part of which railing corresponds to the proper railing.
We do have tutorials for how to use a matte for better foreground/background separate tracking
If the railing is in the BACKGROUND, you’ll still want to use.
We don’t have a tutorial for splines yet, but we do have sample projects on our help site here https://help.revisionfx.com/tutorial/49/ (make sure to read the README after you download the projects). Make sure to read the manual section first (The manual was installed upon your disk when you installed Twixtor, in the same directory with the plugins in the /Library/Application Support/Adobe/Common/Plug-ins/CS6/MediaCore/Twixtor5 folder).
The examples aren’t tutorials per se, but examples of how a properly set up project would look like. There are very simplistic examples with mattes and points, mattes and splines, and then a very complicated example with several foreground mattes and splines AND points.
Pete