1. Lecture 3 CS148/248: Interactive Narrative UC Santa Cruz School of Engineering www.soe.ucsc.edu/classes/cmps248/Spring2008 michaelm@cs.ucsc.edu 10 April 2008

2. UC SANTA CRUZ Process Intensity  Process intensity - term coined by Chris Crawford  Refers to the “crunch per bit” ratio  How much processing does the computer do on the data?  Instantial assets – data displayed by computer  Sound files  Bitmaps  Text  Animations  …

3. UC SANTA CRUZ Instantial assets: a temptation  When first learning to program, instantial assets provide immediate reward  For art and humanities students, might feel more “safe”  But, instantial assets  Don’t make use of the unique properties of computational media  Limit possibilities for interaction  Create an authorial bottleneck  Are computationally “opaque”

4. UC SANTA CRUZ The essence of the medium  The essence of the computer as a representational medium is not  Intervention in the production or display of 3 dimensional forms or visual imagery (tools)  Interaction with a participant/observer (interactivity)  Control of electro-mechanical devices (installation)  Mediation of signals from distant locations (communication)  The essence of the computer as a medium is… Computation, processes of mechanical manipulation to which observers can ascribe meaning

5. UC SANTA CRUZ The conversation model of interaction  Listen – what is the range of possible utterances (verbs) provided to the player?  Think – how deeply does the system process the player’s utterance (understanding)?  Speak – what is the range and complexity of the system’s responses to its understanding of the player’s utterance?  Interaction is a combination of the depth of the listen/think/speak loop and the speed of the loop

6. UC SANTA CRUZ Instantial assets limit interaction  More degrees of interactive freedom require more complexity of response  As the interactor can say more, the program needs to be able to think and speak more  Responses generated from instantial assets…  Limit response to combinations of assets  Require more assets as the range of response grows  Can be an authorial bottleneck  Instantial design tends to limit interaction or collapse response

7. UC SANTA CRUZ Computational opacity  The meaning of instantial assets are opaque to code  Example: code that triggers video clips can’t reason about or manipulate the meaning of the clips  This opacity limits the code’s ability to resequence these assets in meaningful and interesting ways  Assets must be designed for sequencibility or…  Assets must be “opened-up” to the code

8. UC SANTA CRUZ But instantial assets aren’t “bad”  Can tap into rich meaning systems  Complex connotations, emotional flavor…  We don’t know how to procedurally generate rich instantial assets  This can quickly become an AI complete problem  Purely procedural work may be overly abstract  Need to appropriately balance the use of instantial assets and procedurality  Develop strategies for manipulation of instantial assets

9. UC SANTA CRUZ Two analytic frameworks  Laurel (1986, 1992): Aristotelian theory of interactive drama  Structural – what are the “pieces” of an interactive dramatic experience?  Murray (1998): the pleasures of interactive story  Experiential – what does an interactive story feel like?

10. UC SANTA CRUZ Laurel’s treatment of Aristotle Action (plot) Character Thought Language (Diction) Pattern Enactment (Spectacle) Inferred Formal Cause Material Cause Enactment Intensity Catharsis Intensity Closure Dramatic propertiesStructure

11. UC SANTA CRUZ Murray’s experiential categories  Immersion  Engagement; acceptance of internal logic  Transformation  Masquerade; variety; personal transformation  Agency  Action with effects relating to player intention

12. UC SANTA CRUZ Combine agency with Aristotelian categories  Agency chosen as primary  Immersion - engagement and identification  Transformation - change in the protagonist  Agency – not implicit in Aristotelian categories  How does the category of agency relate to the Aristotelian categories

13. UC SANTA CRUZ Structural prerequisites for agency Action (plot) Player character Thought Language (Diction) Pattern Enactment (Spectacle) Inferred Formal Cause Material for action Material Cause Plot Constraints Maximize agency when material and plot constraints are balanced Player intention

14. UC SANTA CRUZ Classic adventure game Action (plot) Player character Thought Language (Diction) Pattern Enactment (Spectacle) Material for action Plot Constraints

15. UC SANTA CRUZ Modern storygame (RPG and openworld) Action (plot) Player character Thought Language (Diction) Pattern Enactment (Spectacle) Material for action Plot Constraints

16. UC SANTA CRUZ Example: Classic FPS Action (plot) Player character Thought Language (Diction) Pattern Enactment (Spectacle) Material for action Plot Constraints