I'll try and answer your questions:
1. Re: Baking out your animation . . .
I wouldn't recommend using the Ziva Cache node as part of your character baking process.
In hindsight, we probably should have named the node Ziva Preview, as the use case we designed it for, was for interactive inspection of a simulation while it is being set-up.
Internally here at Ziva, when we want to bake out a file from Maya, we just use Alembic.
- Re: Looping animation . . .
The reason why you are seeing a pop when you attempt to loop your animation, is because you've been running a dynamic simulation, and the results are time dependent. There are a few options available to you if you want to produce a seamless looping animation.
OPTION A: On the solver node, switch on the "Quasi Static" option.
When simulating in Quasi Static mode, there will be no secondary motion (jiggles, wave propagation . . . ). As a result, the result on the end of the cycle should look much closer to the beginning of the cycle.
OPTION B: On the tissues set the "Inertial Damping" attribute to "1".
This has the same effect as "Quasi Static" for the overall motion of the tissues, but allows for high frequency dynamics (This effect can also be keyed on an off over time, if you just want to ramp it up near the beginning and end of the cycle).
OPTION C: Set your "Frames Per Second" to a very low number (try 1 or 2).
This would simulate the effect of your character moving very slowly - so most or all of the dynamics will have settled down by the time the frame is produced.
OPTION D: Reduce the density of your materials.
With low density, the tissues will oscillate at a higher frequency with lower amplitude.
OPTION E: Split the difference between the first frame and the last frame +1 using a blendShape node to hide the seam.
OPTION F: Mix and Match the above suggestions.
I hope this is of help!