I understand that Absolute Shape Keys are for creating a deformation sequence, and are more practical than Relative Shape Keys when many deformations need to happen one after the next. The trouble is that I'm not sure how to set the timing to match my desired animation length.
1. Why do absolute shape keys increment by 10?
What does the 10 represent? Am I correct in understanding that it is not keyframes, nor seconds, but rather some arbitrary value that gets calculated as a result of the keyframing of the Evaluation Time slider. Why 10 instead of 1?
Furthermore, can this value be nudged to make a shape key come earlier or later relative to the others? The active/selected shape key shows two triangular arrows to the left and right of the value, but they can't be clicked.
2. Why do absolute shape keys need to have their timing reset? When to reset and when not to reset?
3. how can we keyframe a looping animation of absolute keyframes? How can we find out what frame number needs to be keyframed in order to make that animation loop smoothly? And does the first shape key in the list need to be duplicated down to the last position in the list in order for the tweening/morphing to loop?
The best documentation I've been able to find on absolute shape keys is in The Blender Manual, but it's pretty vague. It basically says "reset and drag the slider". And none of the shape key tutorials around the web that I've seen cover absolute to a useful extent.