Righto, I think I've got this sorted out. I'll post what I worked out here, in case anyone else needs it.
Objective: To have fairy-sized characters, who are 1/6 the size of humans, scaled and working in iClone for use in animated story episodes.
Obstacle 1:
When characters were shrunk down to size in Character Creator 3, the mesh for both the body and clothes became distorted:
76% of original size (was 666x19) - Click to enlarge
Solution Found:
Create the character at full size in Character Creator, then scale them down in iClone.
Obstacle 2:When the characters are shrunk down in iClone, the physics for the hair and soft cloth seems to go crazy, and does the same when imported back into Character Creator after scaling:
76% of original size (was 666x19) - Click to enlarge
76% of original size (was 666x19) - Click to enlarge
Solution Found:
After a bit of poking around, I found that this was caused by the collision shape of the character. This behaviour is occurring with the character at 100% as well, but isn't as noticeable. When looking at the collision shape, I noticed that the collision box for the head was big enough to include the hair:
76% of original size (was 666x19) - Click to enlarge
As such, I suspected that the hair was colliding with this collision box constantly, and this was leading to the unexpected behaviour. I also noticed that the collision box for the upper chest seemed to have the hair resting on it, rather than on the skin. I tried adjusting the collision box for a character scaled at 100%, and found that this resolved the issue. I then tried it with a character scaled down to 16% - the size of a fairy.
Obstacles 3 & 4:When the character was scaled down, the elements of the collision shape seem to fold in over one another:
76% of original size (was 666x19) - Click to enlarge
Furthermore, when I attempted to move the collision box with the character at this size, it disappeared off the screen and the move widget suddenly grew larger.
Solution Found:For this obstacle, it seemed as though I'd run up against a limitation of the software. After considering it for a while, I went back to my original objective. I was trying to create fairies that were 1/6 the size of humans. Or to say it slightly differently, I was trying to depict a world where the humans are 6 times the size of fairies. I was thinking in terms of absolute size, when in this case, it's relative size that matters. Once the video is rendered, the viewer isn't going to be able to tell if the fairies were scaled down,
or if the humans were scaled up (I think. This sort of thing is still new to me.). Props can be scaled up. I did a bit of poking around, and found that the water and particle effects can be adjusted so they look bigger.
So that's the approach I'm going to take. I'll make the fairy characters at 100%, and scale the human characters up to 600%.