|
|
 |
 |
 | | | | |
 |
|||
 |
||||||
          |
 |
 |
||||
|
Technologies on the Wane One interesting side discussion that cropped up at the roundtables dealt with AI technologies that developers had played with, but then discarded. Some of these will be familiar, since a year ago there was quite a bit of excitement over the possibilities offered by some of them. Generally speaking, Artificial Life (A-Life) doesn't seem to have gained much use outside of the realm of RPGs and Creatures-style games. A-Life is a natural for RPGs in particular, since it gives developers a way to flesh out a game world using NPCs to do all the dozens of dull and mundane jobs that no player wants to do, but which are vital to the gaming experience. A good A-Life AI can make whole hordes of monsters and NPCs behave realistically with very little CPU overhead, which gives the player the feeling of being a part of a living, breathing world. Last year, a number of developers were exploring different areas using A-Life technologies in everything from first-person shooters to RTS games, but when push came to shove, many ditched those plans in the face of the inherent difficulty of predicting exactly what a given unit would do in a given situation. Developers found, for example, that it really annoyed their producers when they created a 3D shooter level in which a guard was only "usually" at the bottom of the stairs to raise an alarm. Others found themselves wrestling with games in which a unit would ignore the commands given to it by the player — a realistic situation, perhaps, but hardly one the player is happy to be paying for. However, some subsets of A-Life technology have found their way into various games. Several of the recent first-person shooters have used flocking algorithms to one degree or another to handle the movement of herds of monsters, birds, fish, and so on. Some RTS games were also making use of flocking variants for group unit movement, and at least one upcoming space combat game (Babylon 5 from Sierra Studios) plans to make use of flocking algorithms to control the movement of enemy fighter wings and fleets of enemy capital ships.
Genetic algorithms (GAs) also haven't found much use in games in the past year. Again, outside of the Creatures genre (which that game nearly owns entirely unto itself), most attempts by developers to use this technology have fallen flat. The main reason most developers cited was the usual one — too much CPU was being taken up for adaptation and learning that happened at too slow a pace to be useful. After spending several months experimenting with GAs, developers found themselves abandoning the technology in favor of more traditional FSMs and FuSMs. Not only are these more traditional techniques easier to predict and tune, but they demand considerably fewer resources of the CPU.
A few developers did report success in efforts to adapt GAs as tools to aid in tuning their AIs, and they found them easy to adapt to this task. AI tuning is always something of a problem for developers, because by the time a game is near enough to completion to make tuning a meaningful activity, there can be hundreds of parameters that can affect the AI's style of play. Testing every combination is an impossible task, more so given the often tight deadlines looming towards the end of the development cycle. Using GAs to tune an AI lets the developer automate this process, making hundreds of runs of a game using various parameters for the computer opponents. The best variations can be saved out as the basis for the default AIs shipping with the game. |
|
|
Features
