As a newb, I've found the howtos invaluable but I came across a problem when I attempted to write code based on pb.Copyable class. Some of the code holds vaguely described variables such as "state" and "perspective". I've inferred a little bit from other bits of documentation but can't seem to fit it all together. This line was most disconcerting to me:

"XXX: understand, then explain use of varying cached state depending upon perspective."

Anyone help a poor newbie out? Thanks, folks. -- Jeff