Custom scripted behaviors is something we definitely want, but it's not quite ready for the wild yet. There will actually be a demo of this at one of our AE World sessions in a few weeks! And more to come in the future, so stay tuned.
Mirror recording is an interesting idea...we'll add it to the list to consider, thanks for the suggestion!
I think I may be able to accomplish replacement of the hands as follows:
In CH, I would drag animate the arms (without the hands being visible).
Then, in AE, I could use 2D motion tracking. I could have hand graphics move along the motion path of each arm stump, and then I could change the visibility of the hand graphics at certain points during the animation.
Haven't tried this yet. If it works, I'll post it.
That could work. Another Character option: you could also associate different hand shapes with different keyboard triggers, and manually trigger the correct hand shapes by hitting the trigger keys at the right time.
I just tried it with hand triggers and it works very nicely.
Guys, that is exactly what I meant by replacement animation. Thank you!
So, I can attach the different hand images to the end of the draggable image (arm), and the hand images will follow?
Okay, after experimenting, I understand that to create replaceable hands, there also need to be renamed arms, that go along with them.
So, if I want a different hand pose image, I would name it right Hand Fist (1!) and then I'd make a copy of the right Arm and call it right Arm (1!).
Otherwise, only the Fist would appear when I press the 1 key.
The replacement arm doesn't deform as needed, though, because it is still using the original Mousetrack layer.
I am going to experiment by adding a Mousetrack (1!) layer to see if it works.
You can either have the layers triggered by (1!) on a shared mesh with the other layers, or their own mesh (their group(s) set to Warp Independently, or layer name in PS/AI starts with "+" -- see the video tutorial on this Character Animator tutorial - Warp Independently and Mysteries of the Plus from Adobe professional video on Vimeo).
If on a shared mesh, you only need the one mousetrack which moves everything that uses that mesh. If each has their own mesh, you'll need an additional mousetrack (but note that you don't have put "(1!)" on the mousetrack name -- it will automatically not be hit when the subpuppet it's within is invisible.
The forthcoming Preview 3 will make some of this easier (assigning shortcuts & seeing the mesh more clearly), and we'll keep working to simplify.