What are the differences between animation compression types?

Aloha,

I’m curious specifically about what does the ‘optimal’ compression setting do when importing a model with animations. I couldn’t find any information about this in the docs. It simply states “Used for generic and humanoid rig.” Ok, but what does that mean, exactly?
Does this use the same algorithm as the ‘Keyframe Reduction’ setting? Or is it something different? Are the animations compressed on the disk as with the 'Keyframe Reduction and compression’setting?
What does it mean? I’m very curious about this, and the docs seem to provide virtually no explanation. Any info appreciated, please. And thank you.

I wrote in as many details as I could about this on my blog here: Animation Compression: Unity 5 · Nicholas Frechette's Blog

Hi - if you hold your mouse to hover over the option you will see pop-up tool tips to explain each option, I have screengrabbed all three for your convenience:

34699-compression.png

Unity Support