Hello,
the .obj format can include very detailed UV-Mappingdata which allows precise texturing. Wings3D can generate and export it but it seems that GEM ignores it so far while it handles other material aspects well.
(i also dream of realtime paint effect
maybe you should look on squeak (www.squeak.org), nice free multimedia system.
Cheers,
Malte Steiner media art + development -www.block4.com-
blog 4, also available as rss feed: http://java.block4.com/blog4/ next events: pure-data workshop 18.10-22.10 vivid, Birmingham, UK