I lurk in the IRC channel and the mainling list this kind of feature was never discused, it's a natural extention to the technology and so it was just done without any fanfare, documentation, or discussion.

this should not be part of any kind of patent, for that matter, most patents on things that can only be done in software shouldn't either. can you patent a painting? "a method of creating a two dimensional representation of a three dimensional object" - there, i just patented a painting. software has no place in the patent system. and yes, i see things created in software as art not engineering.