With games like Half Life 2, Left 4 Dead, Team Fortress 2, and Portal, and other Source Engine games all having the built in ability to give a playthrough the reflexes of Superman and the Flash combined, it's no wonder that such a definitive game engine should hold a place on TASvideos.org. Source Engine games have almost no recognition on this site, and as an individual fan of the games that possess that engine, I think that not only would a category for such a thing earn us more oppurtunities for gaming science, but it would also get more viewers/members on the site, as well as a small, if not a quarterly amount of fame on the internet. What do you think?
A wise man once said "Damn, that's one hell of a steak."
it's no wonder that such a definitive game engine should hold a place on TASvideos.org.
One of the core tenets of tool-assisted speedrunning is that the original, unmodified game is controlled by pressing keys only. Such a keypress file must be re-playable in such a way that the game behaves exactly as if it were a genuine user who is pressing the keys, and the game just reacts as normal to such key presses.
The reason for this is that the run must be a genuine playthrough of the original game, with no progress that's impossible to achieve by pressing input keys only, and it must be possible to verify that the run indeed is genuine in this sense.
This excludes most PC games with internal gameplay recording abilities because in those games it's not the keypresses that are recorded, but the position of every object (including the player) at each frame. The "replay" then simply goes through this file and places every object as instructed there, at each time stamp.
This means that it's easy to cheat and make the game do things that are impossible to do via normal gameplay, such as advancing faster than is possible by playing. Heck, you could just have the player appear at the end of the level on the first frame, and thus each level would be completed in one frame.
The legitimacy of this type of record file cannot be corroborated, while the legitimacy of keypress files of re-recording emulators can (because in the latter case the emulator does nothing more than to pass the timed keypresses from the file to the game, and the game just reacts as it normally does when those keys are pressed.)
