I can open your files now, and I see how you've represented the flowing water with a moving cylinder rendered as blue eroded glass. Great idea, and it looks great. My problem is that I'm trying to round corners (see attached piping.tcw). Do you have any suggestions how to represent what you've done in my attachment? I could "rail sweep" a circle through my pipe, render it blue eroded glass (or something similar), but I don't know how I would make it look like it's flowing.
Oh, FYI.. My attachment is piping that is ultimately attached to a large vessel where the water is to be distributed.
ummmm! . . . well, I thought you might ask that!
Is it necessary to have sharp 90 degree turns, or, will you in fact be using all smooth radiused corner joints?
Having a, more or less, constant internal section would allow the use of a chain of rotating glass spheres perhaps (being a snug fit inside the pipe) following the neutral axis path. I am just thinking quickly here, as it is time to do other things!
Do you really need
to show the entire pipe as animated? Using a section or two, without the direction changing joints would create a suitable illusion, and, might be easier to do? Animated wavy arrows?
Anyway, I hope this helps.
I might try something tomorrow - no promises.