1、AI challenges in Entertainment and Player Expression,Doug Church AIIDE 1 June 2005,1/6/2005,AIIDE 05,2,Who Am I,Programmer by Schooling Designer/Programmer by Training/Practice Interested in Technology enabling DesignWorked on (i.e. coded, designed) a bunch of old PC games, recently have been doing
2、high-level goal setting/evaluation of (i.e. not real work) a variety of console games,1/6/2005,AIIDE 05,3,This Talk,Initially hoping to do an end-of-week recap kind of thing, discussing trends I saw over the course of the conference and relating them to current industry situationsBut turned out I wa
3、s speaking first,1/6/2005,AIIDE 05,4,So.,Instead, Ill talk about AI related game design challenges I find most interesting as we head to next generation My perception of how the state of the industry impacts AI work going forward This is a game design talk more than an AI talk Primary focus on singl
4、e player games There are no pretty demos or pictures. sorry,1/6/2005,AIIDE 05,5,Topics and Takeaways,Changing landscape in games space How biz model messes with AI evolution Rise of entertainment content What experiences are we providing Opportunities/approaches for meaningful forward steps in the i
5、ndustry, risks,Context,Much is changing in the industry,1/6/2005,AIIDE 05,7,Changes in Market,Growing gap between top-sellers and the rest Growing budgets and team size Clear hook, 30 second experience pitchPromise of direct distribution/ability to hit smaller markets with indie titles remains on th
6、e horizon, unfulfilled, but still discussed Indie market would mean a very different talk,1/6/2005,AIIDE 05,8,Changes in Development,Content the real issue (budget, time, quality) Most games now content led not tech led Data driven everything in order to get done Get programmer out of way, tight fee
7、dback loop Team scale impacting process, creativity Getting everyone on same page Creatively collaborate at large scale Less discipline-based, more task-oriented,1/6/2005,AIIDE 05,9,Changes in Gaming,For many years games were linear sequences of challenges challenge itself as play-value/entertainmen
8、t “world” abstracted and simplified Current trends high world fidelity, and growing open-ended worlds, player choice/customization entertainment aspects/pacing, characters,1/6/2005,AIIDE 05,10,Changes in Fidelity,Graphics: huge leaps in 20 years Scale and density of environments increasing Physics f
9、idelity obviously much better Even design has several new “common styles” of play (trading/collectibles, open-world mission stacks, etc.)Conversation systems? not so much.,1/6/2005,AIIDE 05,11,Changing Players,Online (XBox Live, etc) providing more multi-human gaming opportunities MMOs growing in po
10、pularity, providing large environments for “meaningful” player action Single-player games containing more movie-inspired moments, more watching,The Mainstream Industry,Getting Games Made,1/6/2005,AIIDE 05,13,The Industry Now,Consolidation: Fewer games, bigger budgets Harder to get projects started,
11、approved Risk management central to business Large public companies revenue driven, need big sales numbers regardless of dev cost Licensing IP from other media, or sequel-ing established IPs, major part of forward plan,1/6/2005,AIIDE 05,14,Evaluating Games,Player Fantasy: what experience is being de
12、livered for the player Key Pillars: game feature hooks for players to get excited about and promise play value Uniqueness: competitive landscape Reality Check: can it be done? on time? market windows, competitive product timelines, budget analysis, dev team experience, etc.,1/6/2005,AIIDE 05,15,Rele
13、vance to AI,Improved cover finding is very nice Guys who dont get stuck on corners are nice Non-magical following of a racing line is nice. none of these makes much of a 30 second TV ad, or a quick sound byte for Newsweek . and if the character only lives for a minute, how much fidelity can we even
14、perceive,1/6/2005,AIIDE 05,16,Market Reality,Tons of interesting and hard work goes into making modern game AIs able to work at all but it is expected by the market, and really is mentioned most when it fails, not succeeds Even in specialist press, weve basically bragged our way out of meaningful cl
15、aims “realistic characters respond to your actions” has been said for 10+ years about games and often scripted stuff has more impact/is remembered more by players,1/6/2005,AIIDE 05,17,The Result,AI code can be hard to build, and innovating and improving it is seen as risky So potentially valuable/in
16、teresting features often cut as scope/risk reduction Press/users outcry for better AI usually trivial i.e. pathing and grenade dodging kind of things hard work, sure, but not some new innovation Hard to make case for future looking AI investment given risk profile and low ROI,1/6/2005,AIIDE 05,18,Th
17、at Said,Consumers do get excited when something combines new AI with new play idea/concept Black and White, The Sims, first RTS games Many of these had struggles to approve/releaseCan we encourage/enable more of that?,1/6/2005,AIIDE 05,19,What is needed to Pitch it?,Attach AI feature to compelling p
18、layer fantasy Identify and show a unique player experience/mechanic the AI feature enables Some other pain point of development (cost, time) that the AI technique will improve Evidence it wont require leaping off some 10-year research project cliff into total unknown,Technology Status,What challenge
19、s? What can we do?,1/6/2005,AIIDE 05,21,AI Tech Situation,As fidelity of worlds (graphic environment detail, lighting, terrain complexity) grows, challenge of just keeping up ratchets up pathing on a 2d tilemap with 90 degree walls easy pathing on an arbitrary polygon mesh, not as easy switching bet
20、ween idle and combat sprites easy managing 100+ bone blended model, not as easy and so on. Just keeping old features working is hard,1/6/2005,AIIDE 05,22,Some example AI Tech,Pathfinding Map Analysis (cover, opportunity, shortcut) Group coordination and management Actions (climb rope, fire gun, plus
21、 world use) Expression (what do i say, what anims.) Senses Traits and Characterizations,1/6/2005,AIIDE 05,23,Some example AI Tech,Pathfinding Map Analysis (cover, opportunity, shortcut) Group coordination and management Actions (climb rope, fire gun, plus world use) Expression (what do i say, what a
22、nims.) Senses Traits and Characterizations,1/6/2005,AIIDE 05,24,Enabling Players,Unique DNA of gaming is interaction Currently, we provide lots of micro-interactions (move, shoot, dodge) Lack of support for larger scale player choice Hence drive towards online (where other humans provide the reactio
23、n to the choices) AI is the obvious tool to enable more player flexibility and expression,1/6/2005,AIIDE 05,25,Who Cares?,Plenty of games are fine w/current level of expression (Tetris works pretty well, etc.) And movie style games are plenty funBut we are missing out on a huge range of possibilitie
24、s, and ones that are uniquely us More reactive worlds with more payoffs and meaning to choices will be more human,1/6/2005,AIIDE 05,26,Entertainment Aspects,Big moment payoff in FPS these days rarely comes straight from the systems/AI core scipted overrides with hand-placed triggers/events AI core s
25、upports the set piece by moving actors about, reacting and sensing, but that is it Similarly in many other types. AI controls the mundane character actions, and then in big events the character is put into auto-pilot Pure systems behavior often seen as flat,1/6/2005,AIIDE 05,27,Entertainment and Rea
26、lity,Often as our AIs/NPC setups get better, they become worse as game foils hard to tell what is going on, why opaque actions, no sense of agency Need better demonstrations of NPC traits emotes, drawing attention, some sort of feedback AI needed to support directors goals and feel, not impose reali
27、ty AI to help pacing, variety, etc. lots to try,AI in Games,What are we using this for?,1/6/2005,AIIDE 05,29,AI Styles we use a lot,Opponent Simulates another human player i.e. enemy fighter in SC, general in an RTS, etc Manage Simulates independent agents to attempt to direct i.e. RTS troops, Sims
28、in the Sims, B&W creature,1/6/2005,AIIDE 05,30,Why these styles,Opponent Strategize against player abilities Pick challenges (shoot a guy who is in cover, chase a guy, drive faster than guy) and build AI around that optimization goal Manage Build systems based AIs with limited but repeatable capabil
29、ities Gameplay about player learning to use them,1/6/2005,AIIDE 05,31,Styles and Expression,Opponent and Manage provide clear expression for player in micro-actions taken Presented sequence of small goals, have freedom on how to get there using toolset Often provide a very small-task oriented approa
30、ch to completion Much like a job or homework. checklists,1/6/2005,AIIDE 05,32,Styles we do not use much,Negotiate limited use in RTS environments Converse very very limited conversation tree models, primarily, almost universally prescripted branching Choice and Consequence Occasional forays into fac
31、tion based/multiple valid path, but mostly still save and reload based play,1/6/2005,AIIDE 05,33,Steps toward other styles,Mercenaries very basic faction model, and somewhat opaque and low on consequence (at least for first several hours), but still has NPC reactions to player choice Fable very shal
32、low NPCs, but they pay attention to player actions and shade their opinion/behavior Nintendogs Ok, just another pet sim, but it is non-combat character interaction, and a nice “step” on a path,1/6/2005,AIIDE 05,34,Design Challenges,Growing AI complexity makes expression harder in some ways what were
33、 they reacting to? did what i do matter? is he my friend or did he just not see me or am i wearing a disguise or maybe. Add a complex behavioral/sensory model and getting meaningful player feedback is tough Another reason pure opponent model is nice,1/6/2005,AIIDE 05,35,Design Needs,What tools addre
34、ss this, can designers use them, what feedback do they get? Tension between automated response and precise controls, where is sweet spot? AIs need to be Robust, Contextually aware, and Controllable. not an easy balance Esp. as world systems grow in complexity Getting good at this for micro-tactical
35、combat setups. but not much for levels above this,Going Forward,What are we doing?,1/6/2005,AIIDE 05,37,Optimistic View,Keeping up, AI can manage characters in increasingly complex settings Games to keep moving forward Complex settings give options for expression More scope for entertainment as we c
36、an create more compelling and full worlds,1/6/2005,AIIDE 05,38,Pessimistic View,Existing trajectory continues to evolve a small set of games, ignoring many more Great, we master low-level tactics No player-driven character interactions, scripting the choice for memorable entertainment moments Single
37、 player games become movies with tactical/combat/physics challenges to “turn the page” to the next scene Single player as “training dummies” for online,1/6/2005,AIIDE 05,39,Proactive Response,Reality somewhere in the middle Cant wait for more interesting AI integration and adoption to “just happen”
38、Need to address current industry needs (entertainment, risk management) w/o giving up on pushing other AI typesNote: Nothing wrong with better pathing/etc, but is that all we can do?,1/6/2005,AIIDE 05,40,So we need to get ahead,Finally good at doing games in Year 2000 20 person teams, static worlds,
39、 a few characters Ooops, a bit late, eh? Where do we need to get ahead Tools: get on par with graphics/world fidelity middleware? more sharing of tech ideas? Tools: better blend of AI systems behaviors and “script-like” entertainment elements. Risk: need manageable steps, solid path,1/6/2005,AIIDE 0
40、5,41,Some Pain Points to address,Dev Costs w/o better AI tools wont be able to build content, due to pain of path management and scripting Necessity of more complex worlds if-then structures will become unmanageable, get more flexible and robust solutions going now,1/6/2005,AIIDE 05,42,Opportunities
41、 to go for,New styles Hard to make them work, but when you do, and connect them to a market, you are very happy “Real AI” planning, learning manageable but meaningful steps into games Entertainment flexibility to allow big moments to be attached to real choices would be very compelling Take gaming big moments back from the movie people, make them interactive,The End,
