Saturday, August 14, 2010

Facade and Procedurally Generated NPC Responses

A few weeks ago, I had the honor of meeting Michael Mateas with COSMOS. Mateas is an associate professor in computer science charged with running the Expressive Intelligence Studio, a lab where research in dynamically generated content is preformed. His field of study specializes in advanced AI, furthering advances in autonomous characters and interactive storytelling. The product of the EIS’s research is Facade, a stellar piece of experimental software years ahead of today’s perception of interactivity.

facade screencap  Facade falls outside of the currently recognized aesthetics in contemporary game design. The player can move around the environment and interact with objects in the first person, but most important is the player’s relationship to Facade’s two NPC characters. This is where the game’s innovative experimentation shines.
All of the NPC’s animations and dialogue is procedurally generated in real-time. Unlike Bioware’s prerendered dialogue trees, Mateas assigns values to words that the player inputs to generate animated character models and return NPC dialogue. Trip and Grace (Facade’s NPCs) are fully voice acted using pre-recorded “snippets” of dialogue, these snippets are strung together within the program to produce grammatically correct and cogent sentences. These procedurally generated NPC reactions are nearly indistinguishable from pre-rendered reactions. Thus, Facade’s experimental AI is highly advanced and years above commercial AI. While it is not far removed from existing AI chatterbots, the integration of natural language simulation into a game-like scenario

Nonetheless, Facade’s 2005 technology still has its flaws. Several minutes into play, I encountered a situation where I input something that the AI couldn’t respond to (but again, not a lot of people know about The Game, even fewer AI chatterbots). Facade managed to cover up this hole well, the NPCs would say “what?” or “pardon” to these inputs. Procedural animation and 3D character modeling also looks primitive to modern pre-rendered animation and models. At certain times, characters would become horribly disfigured spontaneously. But given the experimental nature of these advances, such flaws are forgivable and Facade wholeheartedly succeeds at what it is meant to convey.

012208-0339-masseffect1 With the mainstream success of Heavy Rain, a PS3 interactive narrative powered by controller input rather than artificial intelligence, it is safe to say that future games will have this type of NPC interaction. Advances in voice recognition technologies could bring this type of interaction to home console games that lack keyboard input. WRPG games would be especially benefited by autonomous AI. BioWare and Bethesda games have been holding a similar brand of NPC interaction for years, albeit with pre-written inputs and scripted responses. Should procedural animation and dialogue technologies continue to advance to appear in commercial, mainstream games, the industry effect would be amazing The use of autonomous AI in commercial games will make gaming more immersive, emotionally meaningful and artistically relevant than ever before.

Facade can be downloaded for free at, you’ll need a BitTorrent client to download it.

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