Very good course...
I have spent quite a bit of time using the approach of mixing 2 animated patterns that match at the ends of the loop. Of course this produces a seamless loop.
One thing that often seems noticeable to me is at the 50/50 mix point, the combination of 2 patterns tends to look different from either pattern at the ends (more or less density, shape variation...). It depends a great deal on the exact patterns and the mix method used.
I've experimented with using sin() / cos() type variations to produce a "circular looping morph", with some success. It's a bit more complex. I guess this is a pretty fundamental issue that everyone faces. Maybe someone has a more elegant solution?
Hi techworker1 ,
Good question!
Imagine a Camera flying through a Torus, looking at a 2D 'slice' of a 3d Texture that is in the (volume of the) Torus.
Set up in Blender could be something like this:
Don't Render the Torus, I just used it for it's Texture Coordinates.The Plane is Parented to the Camera, which is Parented to the Circle.
Note that there is no slow down or speed up of the Texture changing. It's a perfect loop.
(I have answered questions like this quite a few times and each time I come up with a better solution...although they are all based on a similar principle.)
That will always be an issue, we try to hide it the best we can but it's not always a straight forwards process of click here or add this. Since every setup is different, the best we can do is fiddle around to try and hide the transition, but yeah it's always so tricky, I don't really have a super answer.
Very interesting 
spikeyxxx , I wouldn’t have thought of that. Probably will give it a try.
the only problem (I know of) with this method, is that is rather fast...for a slow moving Texture (increasing the Radius of the Circle), you'll need a lot of Frames per loop.