advance parallax effect and fluid head turns

You could experiment with adding transform behaviors to lower levels in the the puppet. E.g. I put transforms on the hands to do things like rotation of the hand alone. I tried this with my HTC Vive integration experiment. HTC Vive Head Position and Rotation Demo (Adobe Character Animator) - YouTube - I was controlling the puppet using HTC Vive controllers. The Vive controllers were generating MIDI events which was controlling the different transforms on different body parts. I guess you could record a replay for individual parts of the body, so trigger it with keyboard/MIDI triggers (e.g. in live session - like a hand wave).

I agree on the pain of head turns and redoing expressions for each turn. I have avoided them to date for the puppets I have created, mainly for that reason. I was also trying to get Paralax going. I was wondering if it would be possible to synthesize a puppet programatically once a pattern was worked out, but the SDK is not released yet. E.g. have a template for getting parallax going, then tweak some parameters to adjust different characters.

I did get a little luck with getting a jawline looking a bit more natural as the face turns (the jaw moves slightly faster than rest of face, so it looks like the chin sticks out. Sorry, I take that back. I got it moving, it did not look natural yet! ;-)

Regarding the eyes, feel free to drop in some screenshots. I would look for stray Eye related tags in the artwork. Go through each layer one by one and look at the tags. Look at the yellow and blue bounding boxes at each layer. Sometimes I have found parts of the left eye in the right eye artwork etc. Or an additional tag for a pupil in the other eye, causing it to get confused. It has often been as simple as removing a tag. Feel free to share your puppet if you want me to have a quick look, or show some screen shots of rigging with different eye layers shown and highlighted. Seeing the yellow and blue outlines might reveal the problem.

It seems like when two behaviors try to control the same layers, one wins. So because there is a mouth behavior, the mouth parallax no longer works. But what I found you could do was put the Mouth layer as a child of the Nose layer, then the mouth will move with the nose.

I believe it should be possible to get the ears moving in the opposite direction, but might not be easy To get it all looking natural. You need to get hair etc moving. Also you cannot change the proportional width of the eyes, so you would only get a bit of movement. I wonder at times whether it is the right thing to do versus just draw the puppet at different angles. I mean is it still a cartoon? Or should use use a 3D rendering engine if you really want 3D. (E.g. Unity 3D.)

I had played with trying to do a head turn. I was experimenting with pinning parts of the jawline, to get a side on view of a character with the jaw and cheek bones etc. But I really had to ask whether I was doing the right thing. I did not get that far with it.

Eye pupils going the wrong way is normally due to the eye pupil layer being larger than the eye pupil range - which can be due to stray pixels in the layer. I wrote a blog post on eyes https://extra-ordinary.tv/2018/04/21/debugging-character-animator-eyess/ - in particular, look at the end with the added section on “crazy eyes”. You can get some really interesting things happen at times. Also have a look at “Project Wookie” - there is an episode on eyes. https://extra-ordinary.tv/2018/10/22/project-wookie-a-beginner-youtube-playlist/ (17 to 21, where 21 is on crazy eyes).