Nikitas M. Sgouros
Working Notes, by Zach Tomaszewski
for ICS 699, Fall 2005, directed by Dr. Kim Binsted
- At University of Piraeus, Greece. Associated (now) with interactive performance and robotics performance.
Sgouros, Nikitas M. "Dynamic generation, management, and resolution of interactive plots." Artificial Intelligence 107 (1999) 29-62.
- Current state of tech: story graph (hypertext) structure or simulation.
- Propose computational framework balancing interactive and plot control. Aristotelian conception for dynamically structuring plot.
- Use a Plot Manager. Input: description of cast members. Output: series of character actions. Shapes user interaction, controlling cast characters and user protagonist's options. Generation, Evaluation, and Resolution units.
- [Link to crappy/confusing demo applet.]
- Generation of possible interactions. Based on Role descriptions, Initial Plot Conditions, and Social Action rules. Evaluation according to dramatic significance; select most "interesting". If no interesting solutions can be found, go to Resolution to compute the outcome of the character interactions based on hierarchy of motives and character consistency.
Output is a temporal sequence of character actions.
- Two types of intervention (which can be positive or negative): goal intervention (helping or obstruction someone's pursuit of a goal) or normative intervention (seeking compliance with a norm).
- [Some language examples of these rules.] Building solidarity between characters by following the same norms. Goals that conflict with norms. Success or failure of an action. Conflict between actions. Choose an action that uses as much of the story background as possible (such as involving more characters with pre-established relationships, to preclude early story conclusion.)
- Interrupts Generation when detects dramatic potential, or when user acts.
- Dramatic situations: Lifeline (unfavorable followed by favorable intervention--ie, healing), Rising-Complication, Reversal-of-Fortune (change in intervention), Irony.
- Pick situations that involve the user over those that don't.
- User can conform to or react against actions directed at him.
- User actions are preferred to situations that simply involve the user.
- Seeking unity of plot, and parsimony. Affiliate certain interventions with story goal. Accept as plot developments only character interventions affiliated with story goals (maintaining unity). Limit the conflict between two characters over goals related with the story goal to certain number (to prevent infinite interaction, spoiling parsimony).
- In "Aristotelian" style, plot resolution should provide unambiguous solution, based on character motives. Should sustain dramatic power by supporting unexpected plot twists.
- Determine motives of all user actions: which goals will be met and norms protected if user actions succeed (S+); which goals will fail and norms be violated if they succeed (S-).
- Determine relative importance of motives and resolve user action accordingly: if some goals/norms are in both sets, the user is wishy-washy, so all user actions fail. In current impl., norms higher precedence than goals.
- resolve action of other characters: to provide plot twist, those with goals in S- succeed if user's S+ prevails.
- establish presentation constraints: establish causal ordering of action outcomes, and resolved conflicting actions (success first, then failure--easier to understand).
- Player, with goal to worship Poseidon. King (user enemy), priestess, judge.
- Player tried to sacrifice in order to worship Poseidon. The king, to thwart this goal, forbids it (violating norm of worshipping the gods). Priestess intervenes (by asking Posiedon for help). User can comply with king (and fail to reach goal) or confront him (violating norm of obedience to royalty), which prompts judge to intervene. Complying with judge precludes succeeding at any previous goals, so can hide. King banishes priestess for her meddling. [Reached max number of interactions, so start resolution.]
- Plot experienced in 3D world. (Involves things like getting past the palace guard.) [Seems to lead the user around with text prompts.]
- Another applet, which won't init with: "java.lang.NoClassDefFoundError: vrml/external/exception/InvalidNodeException." Mozilla also gives plugin complaints, but can't determine what the plugin is.
- Reminds me of Crawford's verbs. Motives and social norms, with some fudging in resolution preference for the benefit of dramatic tension.
- I see no resolutions on any of these--succeeding on orginal goal.
- Interesting application: building different norm hierarchies based on different religious or political systems.