Feature Focus: Text Animation of Character Offset with Preserve Case & Digits now supports KS X 1001
Text Animation of Character Offset with Range Type Preserve Case & Digits has been enhanced in After Effects Beta 22.4 (41) to include the coded character set KS X 1001 which supports hangul and hanja characters.
You can read more about this particular character set here: KS_X_1001
Just to review, the Range Type Preserve Case & Digits defines a set of Unicode range groups whereby when After Effects adds a positive or negative offset to the base character it is animating the resulting Unicode character is wrapped around so it stays within the same Unicode range group as the base character.

For example, consider the upper case Latin letter "Z" which is part of a Unicode range group for upper case Latin letters that spans from "A" to "Z". When we add one with the Character Offset we generate an upper case Latin "A" instead of getting the next Unicode character after "Z" which is the Left Square Bracket "[". Neat, eh?
With Character Offset Range Type Full Unicode there is no constraint so with the right starting base character and a big enough Character Offset one can end up with some pretty unusual characters most of which are probably not even supported by the applied font.
All this is driven by a table of Unicode range groups which I thought you might enjoy seeing.

Douglas Waterfall
After Effects Engineering
