Worlds, Spin, and the Revolution of Curveship

This is the third in a series of posts about my interactive fiction system, Curveship.

Before I start descending into detail, I’ll explain why I think Curveship is a big deal.

Curveship does the usual work of an interactive fiction system when it comes to simulating a world: There are discrete rooms that make up the fiction’s locations, actors can inhabit and wander around these rooms, and things can sit in them, be taken and carried off or otherwise moved around. Items can change state, so that a lamp, for instance, can be turned on and off. Items can go into or onto other items, if they allow it. None of this is surprising; plenty of interactive fiction development systems already do all of it very well.

Hypertexts don’t do that. Hypertexts, including Web hypertexts but also pieces in HyperCard, Storyspace, Twine, and similar systems, present a structured document in which some phrases are hooked up to other pages. They might have guard fields or other pieces of code, but at their most essential, they are really strange surfaces of text, with phrases connected in an unusual topology.

Nothing’s wrong with hypertext. If you want to create an unusual language surface, to link pages together into a curious structure, it’s clearly the form to use. The play and connection of language can be intriguing and relevant. You can make a compelling literary work in this form, as several people have done.

But interactive fiction systems allow something else. You can put a simulated world underneath the text that people see. This lets you create different types of literary systems, which can be nice: Several people have created interactive fiction systems that are compelling literary pieces and that couldn’t have been realized as hypertexts.

In an important way, Curveship is to interactive fiction what interactive fiction is to hypertext. Just as interactive fiction added a new and significant model – a model of a simulated world – Curveship adds a model of the telling, of the narrating, of the way that the simulated world is represented in language. Curveship adds spin, as in the spinning of a tale and as in Spin Alley.

Curveship can leave actions out of the narrative, can reorder actions in the narrative to create flashbacks and flashforwards and retrograde narration and narration by category, can narrate at greater or lesser length, and can represent several actions in one statement or repeat the narration of a single action several times. The system can tell about what is happening in the simulated world from the perspective of any specified actor, based on that actor’s knowledge and perceptions, or it can narrate from a global perspective. It can tell about what has happened in the past just as easily as it can represent a current action.

The system is able to do this because it models every action that happens in the world, just as existing IF systems model every item. First-order representations of actions differentiate Curveship from other IF systems. And on that of that, a complete text generation system has been built, allowing for grammatical changes that follow from high-level narrative parameters – the spin.

Consider The Odyssey. Why is it interesting? Why has it shaped world culture and remained memorable for thousands of years? Yes, lots of interesting stuff happens in it. But the way it is told is also tremendously compelling – Odysseus listening to the song of his own exploits, shielding his eyes and weeping, being identified as the great hero, and then going on to tell the next part of the story in his own voice. That’s as fascinating a part of The Odyssey as is the encounter with the Cyclops or the slaying of the suitors. And the telling surely becomes more important in contemporary literature. Is Lolita really more interesting because of what happens or because of how it is told? What about Ulysses? To the Lighthouse?

Curveship’s modeling of the telling adds to the significant power that IF already provides by way of a model of a simulated world. Just as IF adds a simulated world to hypertext, Curveship adds control over the telling (that is, it adds spin) to the simulated world.

Those who want to create strange surfaces of text will want to work in hypertext. Those who want to have a simulated world will probably use an existing IF system. For those who are interested in varying the telling, as many great authors have done in oral, written, typed, and word-processed literature, it will be best to use a simulated world and spin: Curveship.

A Lexicon of the Curveship World

This is the second in a series of posts about my interactive fiction system, Curveship.

In writing about Curveship in any detail, I’ll have to use terms such as action, event, and order, which sound ordinary but are used in a special way in the system. Furthermore, I’ll have to use terms such as focalization and narratee, which do not sound ordinary, but have a meaning within narratology (a.k.a. narrative theory) and are important to the way Curveship works. I’m going to define a few of these terms – some I’ll save for later. Rather than sort them alphabetically, I’ll group them by how they figure in the system.

Worlds of Curveship

Actual World. Following Marie-Laure Ryan’s terminology, I consider the main, simulated interactive fiction world to be the “IF actual world,” that is, what is “actual” from the standpoint of the player characters and other actors. I’ve bothered to give this a special name (rather than just calling it the world) because it isn’t the only ball in play in Curveship.

Concept. A concept, formerly called a “focalizer world,” is a particular actor’s theory of the actual world, based on knowledge (put into a fiction file to begin with) and perceptions (gained as the actor moves around and looks at things). Concepts are almost never complete, and they may be wrong. They allow the telling of actions and the description of items to be focalized, that is, based on what a particular actor knows and sees.

What Exists in the World

Item. Basically, any object that has a representation. I could have called them “objects,” but that term means something different in object-oriented programming, even though items do end up being represented as objects. I could have called them “existents,” the term Seymour Chatman and other narratologists use, but that caused gnashing of teeth among some of the people I consulted, including one researcher whose first language wasn’t English. Items must be in one of three categories.

Actor. An item that can take action on its own, due to either code that an IF author has written or a script the author has dropped in. Any item can react, but only an actor can initiate action. Actors are also the only category of item that have concepts.

Cosmos. The special actor that is the root of the item tree. Responsible for earthquakes, power outages, and any occurrence where the author doesn’t want to model the cause as its own actor. The cosmos can also change the plan for narrating, which allows for a connection between the simulated world and the way the telling of this world is done.

Room. A discrete location which has exits leading to other rooms. Rooms are all on the first level of the item tree, directly below cosmos.

Thing. Generally, an inert item. Any item that isn’t a room and doesn’t need to act or have a concept is a thing. Things can react when something is done to them or done in the same room, so that pressing a switch on a lamp can cause the lamp to react by increasing its glow.

Item Tree. A structure representing all of the items in the actual world (or in a concept) and the relationship between them. It is a graph with a designated node (cosmos), directed links from parent to child, and no loops – that is, no item is its own descendant. Hence, a tree.

Parent-Child Relationship. The relationship between an item and an item a level under it, and connected by a link, in the tree. When an actor walks into a room, he or she becomes the child of the room. If the room moves (perhaps it’s an elevator) the actor will move with it. If the lights in the room become brighter, the actor and everything else in the room will be better illuminated. An apple placed in a sack similarly becomes the child of the sack and, for instance, is stolen if the sack is stolen.

Link. The edges (as they are called in graph theory) of the item tree, each one connecting an item to another item and indicating a parent-child relationship. Links are labeled, with the label indicating more about the relationship. If a person is holding a sack with an apple inside and wearing a cloak, the sack and cloak are the children of the person and the apple is the child of the sack. Furthermore, the link between the sack and the person is labeled “of” (indicating a possession) and the link between the cloak and the person is “on” (indicating something being worn). The link between the apple and the sack is “in” (indicating containment). If you have ever tried to use Inform 6 to model a desk that you can put things on (on top of) and in (in a drawer), something which is not very straightforward to do, you will see an advantage to the way Curveship works.

What Happens in the World

Action. A specific but fairly high-level action taken by an actor. An intended command (such as “get lamp”) usually corresponds to a single action. It also usually doesn’t make sense for an action to partly succeed; it either works or doesn’t, although the first components of it may succeed and later ones may fail. The set of actions is open. Authors can easily make up new ones. Actions are what the system narrates, because they are meaningful and high-level.

Event. A lower-level component of action. There are only five, representing different things to be done in the world. Any action is made of one or more of these with appropriate arguments. The five primitive events are sense, impel, misc, modify, and configure. Only the last two change the state of the actual world, modify by changing a feature of an item and configure by changing the item tree. Events are good for simulating the world – unlocking and opening doors, moving actors from room to room, and so on. But because they are so low-level, they are not very good as a basis for narration. We usually do not want to hear that an actor exerted force on a switch, then turned the lamp on, and then increased the glow of the lamp. But it’s nice to be modeling this under the hood, because if the lamp’s battery is dead, an actor might be able to do the first two things but not the third. If the battery is then replaced, the lamp should glow brightly right away, since the switch is in the on position.

Files of Curveship

Fiction File. What others call the “story file” or “game.” It can be a game, of course. Essentially, though, it defines a fictional (and simulated) world.

Spin File. A very short file with a few parameters and perhaps a bit of code, all of which could be included in a fiction file. These parameters determine how the story is told at a fairly high level. Released games probably won’t use spin files, but sets of these may be used in research and teaching dealing with narrative, because they allow different methods of telling to be applied to the same fiction file (or a set of fiction files).

These are the building blocks of the simulation done in Curveship. I should note that Curveship is designed to mainly simulate the physical world, not emotional states or conversations between actors. And, of course, it models the way actions are represented and items are described based on concepts of that world – it narrates in different ways based on parameters and code provided by IF authors. I’ll discuss how it does that in a future post.

Pythonic Textuality at NYU

I was very interested to learn that Adam Parrish, whose own Interactive Telecommunication Program (ITP) masters project was “New Interfaces for Textual Expression,” is now teaching Digital Writing with Python at NYU’s ITP. The course is concluding; Parrish and his students will mount a final performance on August 5 at 7pm. Parrish eschewed powerful, cryptic Perl for clarity of Python in this course on creating text machines, as I did in putting together The Word Made Digital, which I’ll be teaching again this Fall. His reading list overlaps with mine a bit and includes a nice article on appropriation in writing – I may just rip that right off. I won’t manage to be in New York to hear students read their programs’ output, but I hope the conclusion to the class goes well and that I’ll be able to read and run some things that will give me a sense of the event.

Introducing Curveship

This is the first of a series of posts about my interactive fiction system, Curveship.

Curveship is an interactive fiction development system that provides a model of a physical world, and its workings, as do existing state-of-the-art IF systems (such as Inform 6, Inform 7, TADS 2, and TADS 3). It will not have as many libraries, and will have no multimedia features, when it is released, but it will provide another significant capability: it will allow IF authors to write programs that manipulate the telling of the story (the way actions are represented and items are described) as easily as the state of the IF world can now be changed. While existing IF systems allow for the simulation of a character who can move around and change the state of the world, Curveship provides for control over the narrator, who can tell as if present at the events or as if looking back on them, who can tell events out of order, creating flashbacks or narrating what happens by category, and who can focalize any character, not just a fixed PC or a hard-coded series of them, to tell the story from the perspective of that character’s knowledge and perceptions.

Curveship will have a closed round of testing and revision soon, and will be publicly released soon thereafter. This may happen as early as the end of summer, but if that timing makes little sense for the project or the IF community (IF programmers may be too busy finishing their IF Comp games at that point) the release could happen later.

I have had a very short page about the system up for a while at Curveship.com. As it explains in slightly more detail, the system’s starting point was my too-cleverly-named research system nn. I have been working for a while to get a usable programming interface set, to clean up the code, and to add some capabilities that are necessary for a usable IF system but didn’t have much research value to me, at least initially. Finally, the name of the system comes from a poem by Hart Crane. “Curveship is being fashioned to model the essential qualities of variation—the curve of a story through its telling—just as friendship and authorship represent the essence of being a friend and author.”

I’ve recently given a talk about the system to a group of roboticists and computational linguists at a workshop, and more recently (yesterday) got to discuss the practicalities and details of the system a bit with the Boston IF group; those folks provided some good suggestions at the levels I’m most concerned about now. I’m now going to begin writing, as often as I can, about the system, what principles it is based on, and how it works at high and low levels.

Curveship is a Python framework; to write a fiction file you simply write some Python code, instantiating classes for the most part, writing your own subclasses if you want items to do something unusual. There are a few fairly radical differences between Curveship and existing IF systems, but the two that will probably be most visible are the modeling of actions and the string-with-slots representation that is used for text generation. In Curveship, items do not change their own state. Changes of state, and the movement of items from one place or container to another, are accomplished only by actions. And, when actions are narrated or objects described, this is done based on a formalism that is a bit harder to write than a simple string would be. These are two of the the main aspects of Curveship that, although they demand more work from the IF author, allow for powerful, general ways of narrating.

Ideally, as I continue these posts, I’d like to write in response to your particular interests and curiosities. I’ll be glad to answer questions in comments if there’s a reasonably sort answer; if not, I’ll try to answer them in the context of a longer post.

Web Comics Touched by the Brush

The Moon Fell on Me is an infrequent, gemlike Web comic by the itinerant Franklin Einspruch, who happened to come to my recent interactive fiction talk at AXIOM. He told me he was trying to do something different with this Web project. Visit his site even briefly and you’ll see that he has done it. No pen was used in the creation of this Web comic. The panels are not organized to lead toward jokes. The lines of images are clearly based on personal experience, but they reach out beyond an individual or subculture. Instead of the occasionally hilarious, forward-a-link, forget-in-moment frames of the typical Web comic – however incisive that comic might be about geeks or life or both – The Moon Fell on Me offers sequential art that is worth looking at again and again, that resonates with its moment and seems worth contemplating beyond it.

Story Generation with Pookie and JR

Excerpts from the Chronicles of Pookie & JR:
Previously, Pookie and JR had only ever met at parties.
For the first few nights, Pookie and JR keep to their corners.
JR changes Pookie’s water. Pookie makes a mess of his feeding dish.
JR cooks slowly, foraging in this strange kitchen.
Tonight’s dinner puts one withered leek out of its misery.
JR hasn’t been sleeping much lately.
Pookie keeps his thoughts to himself.
To be continued…

J. R. Carpenter, author of Words the Dog Knows, Entre Ville, The Cape, and other fine works of e-lit, print, and xerography, has delightfully repurposed one of my 1k story generators to have it tell stories involving her and a hermit crab named Pookie. The program has grown to about 2k, but it uses the same simple (and surprisingly effective) method as my first generator does: It simply removes all but 5-9 sentences from a sequence, eliding some of what’s been written. Sometimes the reader is left to wonder who the hermit is. Here’s a direct link to the Python code for the program, and here’s the page on Excerpts from the Chronicles of Pookie & JR.

Rafael Pérez y Pérez to Speak at MIT

Next week, the Purple Blurb series offers a second special summer talk by a leading researcher in creative text generation. Rafael Pérez y Pérez will speak on …

MEXICA: A Computer Model for Plot Generation of Prehispanic Stories

MEXICA is a computer model that generates plots for short stories about the Mexicas, the old inhabitants of what today is México City, based on the engagement-reflection cognitive account of writing. During engagement MEXICA generates material guided by content and rhetorical constraints, avoiding the use of explicit characters’ goals or story-structures. During reflection the system breaks impasses, evaluates the novelty and interestingness of the story in progress and verifies that coherence requirements are satisfied. In this talk I will explain the main characteristics of the system, I will show how emotions are employed to progress a story in a coherent way and generate novel situations, and how the dramatic tension of the story in progress might be employed to evaluate its interestingness. I will present results showing how story generation is affected by various model parameters and I will compare MEXICA with other story-generators programs. Finally, I will mention how we are employing MEXICA as starting point for new research projects.

Pérez y Pérez will speak on Wednesday July 15, 6pm-7pm, at MIT in room 14E-310. This is in the same location as Pablo Gervás’s talk in May, and just one more floor up the stairs from the Trope Tank, where other Purple Blurb events were located. The talk is (as with all Purple Blurb presentations) open to the public.

Rafael Pérez y Pérez.
Rafael Pérez y Pérez, creator of the MEXICA story system.

Rafael Pérez y Pérez earned a BSc. in Electronics and Computers at Universidad Iberoamericana in México City, a MSc. in Knowledge Based Systems and a DPhil. in Artificial Intelligence at Sussex University in England. His research has focused on computer models of creativity. He and his students have developed programs that write short stories, compose music, and solve geometry problems, among other things. In 2006 he organised the Mexican Creativity, Cognition and Computers research group (MCCC) which aims to gather together a multidisciplinary group of researchers and students interested in computational creativity. He has published different papers in the area and has participated as a PC member and co-chair in international events related to computational creativity. Currently he is a researcher and lecturer at The Autonomous Metropolitan University (Universidad Autónoma Metropolitana or UAM) in México City and an invited Lecturer in the MSc and PhD programs in Computer Science at The National Autonomous University of México (Universidad Nacional Autónoma de México or UNAM).

Academic Job and Event Postings 2009

If you have an announcement of a faculty job opening in digital media or want to mention an upcoming event (conference, workshop, or symposium), this is the place on Post Position for that. Just leave a comment.

Grand Text Auto is Back

Grand Text Auto, for six years (May 2003-May 2009) a single blog with six co-authors (Mary Flanagan, Michael Mateas, your very own Nick Montfort, Scott Rettberg, Andrew Stern, and Noah Wardrip-Fruin), is now back as an aggregator of four blogs by the original GTxA authors, including this one. Check it out. Update: Thanks to Josh McCoy of UC Santa Cruz, who set up this new formulation of Grand Text Auto.

Plotkin on Rule-Based IF Programming

I’ve been meaning to write something deliberate and detailed about the May 3 Penguicon talk, “Rule-Based Programming in Interactive Fiction,” by Andrew Plotkin (a.k.a. Zarf). And I’m still waiting to do that. I didn’t want to wait any longer to mention the talk on here, though, since it is presented very well in its Web version and will be useful for many people. It’s an intriguing discussion of the other major idea behind Inform 7 – the one that isn’t “natural language” programming. The discussion of how to code interactive fiction is one I’ve been mulling over as I continue to work on Curveship. I think providing first-class representations of actions is very helpful in dealing with some of the problems Zarf addresses, although it doesn’t solve everything by itself. And I think that having representations, within actions, of atomic events (such as exerting force on something and thereby touching it) deals with another of the problems that Zarf mentioned. But I’ll have to leave the extended discussion of that for another post.

Computational Creativity at ICCC-X

The First International Conference on Computational Creativity will be taking place in Portugal on January 7-9 2010. ICCC-X will follow on a decade of smaller-scale workshops and symposia. The call for papers lists the deadline of September 26 (extended 5 days) for papers, and promises:

The conference will include traditional paper presentations, will showcase the application of computational creativity to the sciences, creative industries and arts, and will incorporate a “show and tell” session, which will be devoted to demonstrations of computational systems exhibiting behaviour which would be deemed creative in humans.

Note also that contributions are solicited in several areas, including “specific applications to music, language and the arts, to architecture and design, to scientific discovery, to education and to entertainment.”

Twine is Rolled Out

Twine

Chris Klimas, the hypertext and IF author who runs Gimcrack’d, has just released free versions of Twine for Mac and Windows, along with documentation and several screencasts that explain how the system works and a command-line tool, called “twee,” for working with stories in Twine’s format. Twine is a system for constructing interactive stories using a visual map, not unlike Eastgate Systems’ Storyspace. While it lacks the august heritage of that piece of software, Twine is freely available and free to use for any purpose, even commercially.

When Twine build a story for publication or for the author’s examination, it does this in HTML/CSS. That means that readers won’t need any special software to explore stories written in Twine. Lots of text formatting can be done without getting into HTML and CSS, although authors are welcome to get into it as deeply as they like. The system supports some sophisticated presentation capabilities, including a stretchtext mode. It’s not quite a guard field, but the “choice” macro locks off certain options when others have been taken. Under the hood of Twine is TiddlyWiki, a personal Wiki took for the Web. This handy personal notebook system has been reshaped for interactive narrative rather than productivity, though, and pretty thoughtfully.

Having just started up Twine and fiddled with it a bit, I’m impressed at how easy it is to use, even if one doesn’t read the documentation or watch the screencasts first. It seemed at first that there would be no way link two different occurrences of a word to two different texts, but after a quick bit of reading I was able to figure out how to change [[word]] to [[word|word2]] in one place and give one of the links a different internal name. I’m looking forward to using Twine (and probably twee) further. It could be useful for doing a small project – perhaps a collaboration? – and it might work well as an option for students, too.

Jack Toresal and The Secret Letter Released

Jack Toresal and The Secret Letter

Michael Gentry, author of the stunning, large-scale, Lovecraftian interactive fiction Anchorhead, has another full-scale IF, his first since that award-winning game came out in 1998.

Dave Cornelson, who founded the Speed IF competitions and the IFWiki, has led his interactive fiction company, Textfyre, to publish its first game.

The game that is so notable in both of these ways is Jack Toresal and The Secret Letter. It is available for either Windows or Mac for about $25. As with all of the planned offerings of Textfyre, this game is directed at a specific audience: young readers wanting to experience the pleasures of reading while playing computer games. The hope, no doubt, is that parents will appreciate the fun and literacy-enhancing qualities of interactive fiction.

You can check out the game online: There is an in-browser demo that runs using Microsoft Silverlight. (The game itself was developed in Inform 7, and was programmed by Graeme Jefferis, not Gentry.) The interface offers a book-like framework for the IF session and allows the player to flip ahead to a map or back to previous sections of the transcript. The illustrations were done by Erika Swanson. You can read more about the development of the game and the progress of the company on The Textfyre Times, Dave Cornelson’s blog.

The setting and the situation at the beginning of Jack Toresal is quite compelling, and after only a bit of interaction, I could see already that there are some interesting twists (including gender play), lots to explore, and a variety of people to meet and conversations to have. (I’ve played the game just a bit on my own; I was glad to also get to play and discuss the game with the Boston IF group yesterday.) Gentry’s writing is appropriate to the game’s audience, and is also effective and lively. Although this game probably lacks the tentacle attacks and generations of incest that made Anchorhead so chilling, it doesn’t pull punches for the kiddies – you can get Jack very unpleasantly killed if you don’t lead him to outwit his opponents.

Since Cascade Mountain Publishing ceased its run in 2000, I haven’t heard of a commercial IF company or publisher that has completed a project and released a game. Yes, there have been people selling their own IF in various forms – I’ve been one of them, with my hardback edition of Winchester’s Nightmare; Peter Nepstad has also sold his 1893: A World’s Fair Mystery. But Textfyre seems remarkable in accomplishing the commercial development and publication of a piece of interactive fiction that otherwise wouldn’t have been written, in putting together projects that involve many people. The company has wisely focused on a particular market, and on a particular type of reader/player that is not well-served by existing IF. Textfyre used a new development model in which programming is separated from writing and design, which themselves are potentially separated. (Gentry did both in this first title, but that won’t particularly be the case in others.) This first result, even though it is for younger readers, seems to be a good use of a major talent. Even to us older readers, it could be as interesting as a major release from an independent author. I’ll look forward to playing Jack Toresal and The Secret Letter further, and will hope that this release will just be an auspicious beginning for Textfyre.

A Machine to Play Pitfall

Carlos Diuk, Andre Cohen, and Michael L. Littman of Littman’s RL3 Laboratory at Rutgers devised a new way of doing reinforcement learning, using Object-Oriented Markov Decision Processes, a representation that looks at a higher level than usual and considers objects and interactions. They had a paper about this at last year’s International Conference on Machine Learning (ICML). Better yet, they demonstrated their OO-MDPs representation by using it in a system that learned to play Pitfall in an emulator. I don’t believe that the system got all the treasures, but watching it play and explore the environment was certainly impressive. It seems like the technique is an interesting advance. By trying it out on a classic game, the researchers suggest that it will have plenty of “serious” uses in addition to being used in video game testing and in game AI.