John wrote: >Keep in mind that some actions are not atomic like this. True; a single-use Undo button wouldn't be helpful in a puzzle-oriented game. As I recall, though, even the babelfish dispenser didn't have wrong turnings that you would want to undo; it was just a progressive series of steps that you had to figure out. Were there things you could do with the fish that would result in an unsolvable state? (It's been years since I played Hitchhiker's Guide... And actually I think I gave up on the game after solving the babelfish. Too annoying.) ...anyway, I was thinking more of situations like a pair of doors at the end of a hallway. You pick door A and go through it (...and there's a tiger... :) ) and have some sort of adventure, but you wonder how things would've gone had you picked door B. Rather than (a) having to play the whole game/story up to the choosing point again, or (b) having to save the game before making any decisions, it'd be nice to be able to say "back up to the last place the software considers a Major Turning Point and let me take another branch of the tree." The idea was meant to partially simulate the fact that in CYOA books I always backtrack up the tree trying all the possibilities... >I think a SAVE key is simply an UNDO abstracted out into the >arbitrary past... Except that it's decide-in-advance rather than retroactive. >An apparatus like this done in VRML would be rather difficult. :) Yep. One of the disadvantages of VR is having to leave less (visual stuff) to the interactor's imagination. ...That is, that'll be a disadvantage until VR can easily approach the level of visual detail of a movie. "Trespasser" sounds cool. I saw a realtime physics library at last year's SIGGRAPH that looked pretty cool too; I'm hoping this stuff will make it into the mainstream fairly soon. --jed
