Hi NNenov,
Thanks for the file.
First of all, let me clear the term Loop. A real loop is like a walk cycle, a motion that does something and without reversing the motion it arrives at the initial state. Anything else is just not a Loop.
To get a smooth Loop, the first and the last frame are NOT identical. This is often taught, but it leads to a small stop. The same frame is one frame ahead of the loop! So the it can smoothly run into this.
A Loop also shouldn’t have an interpolation that is flat on the start and end (like a typical Spline interpolation).
The interpolation “curve” at start and end should have the same direction, preferable as steep as the average curve, but it varies of course!
A linear animation (vs cycle) can only create a “Pseudo Loop”, and should always clearly named as such. To know the difference makes you look better when in an, e.g., brainstorming session with a film team. These Pseudo Loops are more forced cycles and often in need for a manual adjustment, to look smooth. If the duration is short of each “sequence”, it might look boring, so to mix it up a little bit is certainly an idea to keep in mind.
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In your file you have a Noise as “Deform” source. Inside of most noise sources you can work already towards a Loop, with the parameters Animation Speed and Loop Period. (Again, not all noise types have that quality)
I guess this was only a source for your test, and not the target idea, so I leave it here.
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If you have a source that is not really or at all a cycle, you need to blend to get a seamless repetition. This blend is not a simple “one size fits all” procedure, but it is not complicated at all. I have made a little clip about “Animation Clips” and how simple it is to work with them. (A series about is in my Animation for Teams … tutorials here on Cineversity, for all kind of animations)
If you have an animation clip, you can apply it to any animation less copy of your initial file. This allows you to set up, change, adjust and set the transition in the best way. There are so many tools in this option, that you can easily create a Pseudo Loop, and change things easily without having a very predicable animation at all. Set up the Preview Range around the transition and press play, now you can fine-tune your result.
Have a look here, as usual, one minute long, and you can download it.
https://www.amazon.com/clouddrive/share/EuSDBIZ7yfQHLLtsmXeMJX3kJ2qpr0JoyoHAvtAdWdV?ref_=cd_ph_share_link_copy
Let me know if there is any question
All the best