Procedural Destruction and the Algorithmic Fiction of the City

[Image: From Procedural Modeling of Cities by Yoav Parish and Pascal Müller].

Note: This is a guest post by Jim Rossignol.

In 2001 Yoav Parish and Pascal Müller spoke at the SIGGRAPH conference in Los Angeles, California, to present a mathematical city. Their presentation contained an algorithmic approach for modeling city-like topologies. The results were remarkably realistic, and were one among a host of city-like generative systems to appear at the start of the decade.

Another, Jared Tarbell's Substrate (pictured) remains a fantastic example of how a mathematical approach to generating apparently urban patterns can also be artful.

[Image: From Jared Tarbell's Substrate].

But it was looking at the work of Parish and Müller that inspired game designer Chris Delay to develop his most recent project: the cryptic (and as-yet-unexplained) Subversion, of which little is known, other than it relies on large, procedurally generated cities for the backbone of its game world.

Having already been burned by the problems of creating content "by hand," Delay set out to let algorithms do the work of building buildings in his new game. Not only that, but he was determined to create an artistically interesting experience without artists.

[Images: From Chris Delay's Subversion].

Of course, videogames have long been the home of procedurally generated landscapes where numbers and mathematical equations played the role of the visual designer. Early paranoid classic The Sentinel made use of these techniques to create an astonishingly atmospheric 10,000 levels in simple vector graphics, from just a few kilobytes of data. Other games have used similar techniques as a shortcut to creating solar systems and vast fractal landscapes.

But when it came to cities, well, it took a long time for anyone to take up the challenge.

[Image: From The Sentinel by Geoff Crammond].

Rather than opt for procedural techniques, game designers usually elect to build their cities by hand, often with startling results. The re-imagined contemporary New York that features in last year's Grand Theft Auto 4 required a small army of well-paid artists and designers to hand-craft the entire world. Their accomplishment is unmatched, but the cost to the company behind the project is in the tens—and perhaps hundreds—of millions of dollars. To build up a living city from blank polygons is one of the most expensive possible projects in game design.

Delay, whose project is being undertaken with a tiny budget and by just a handful of staff based in Cambridge, UK, does not have the luxury of vast content teams. His vector-drawn city is far less realistic than Rockstar's textured, heaving metropolis, but there's nevertheless a beauty to it. It's a kind of mathematical map of the essential urban environment: there are roads, sidewalks, and a no-man's land of corporate moats around great skyscrapers...

Identify the key equation that define urban patterns, and you, too, can summon a city into existence.

Delay has begun to show off how his cities emerge from the ground up in a series of videos, and he spoke to me about the process.

"I started out with road layouts, and then began to modify the parameters," he explained. "Sometimes you'll get lovely radial, spiral patterns, or you can tell it to create a really rigid Manhattan-style grid." One set of numbers delivers the block logic of American cities, another is rather more like the spirals of Medieval European sprawls. The two merge to create something even more believable. "Every subsequent layer builds on the previous layer," Delay points out, "so the very next layer looks for the spaces between layers, and makes judgments about 'is this likely to be a skyscraper, or to be a house?' Then you zoom in, and carry on. You do another procedural generation process for each layer of detail, filling in that world."

[Image: From Chris Delay's Subversion].

A few weeks after speaking with Delay I attended Thrilling Wonder Stories—a seminar at the Architectural Association in London, curated by Liam Young and BLDGBLOG—where I watched conceptual designer Viktor Antonov explain how he had created a science-fictionalized Paris (for a now-cancelled videogame called The Crossing).

Antonov approached the problem by altering just a few parameters in the standard architectural model. For instance, Antonov had noticed a few fundamental details about how the mid-nineteenth century neo-classical core of Paris had been constructed: big street-level floors, smaller attic spaces, complex chimney stacks. By increasing the emphasis on the lower floors, and stretching them out—and by emphasizing the height and complexity of the chimneys—Antonov was able to create a thematically consistent science fiction Paris.

Simply by altering a few basic architectural parameters, he said, you were able to fictionalize the city, whilst at the same time retaining its fundamental identity. His designs were still recognizably—even mathematically—Parisian, in other words, but they were also otherworldly.

[Image: By Viktor Antonov].

This idea instantly connected back to Delay's project: what parameters would we need in order both to understand and create a science fiction Edinburgh, or Sao Paulo, or Vancouver? Identify the necessary fantasy logic within a procedural city-building system and you could recreate cities with their alternate identity in an instant. An accelerated future Moscow, or a retropunk Venice, instantly sprawling out of the monitor.

And perhaps this is not such an outlandish thing to aim for—especially when you consider the speed at which procedural city projects have been appearing across the tech landscape. Could one of these cities potentially be refitted to allow for this type of radical tweak?

Projects like Shamus Young's impressive PixelCity, or Marco Corbetta's Structure seem ripe for such strange fictions. Corbetta's system is particularly impressive in its verisimilitude: he aims to create a basic engine for rapidly generating the kinds of cities that games like Grand Theft Auto 4 require, and consequently doing so for much cheaper.

Could Corbetta's engine come with a Paris or a Barcelona preload, which could then be put through Photoshop-style filters for alternate reality logic in its architecture? A stronger skyline, weirder street furniture.

[Image: From Marco Corbetta's Structure].

More exciting, at least for the thrill-seeking gamer in me, is the fact that Corbetta is aiming one notch higher than any of his peers: he's aiming to make these cities procedurally destructible. His site contains a demonstration video of neatly arrange office interiors and a domestic library being blown to pieces with a machine-gun. What good is an imaginary city if you can't go inside the buildings? What good is a virtual downtown if you can't go crazy with a bazooka? Corbetta's work preempts these questions.

Further, it conjures visions of massive demolition exercises in parallel worlds—entering an Antonov-algorithm for neo-Rome, where gladiatorial escapades see us going through the walls of the coliseum and into the randomly generated plazas beyond.

That, perhaps, is the greatest promise of procedural cities: that soon they'll be real enough that their destruction will seem like tragedy.

[Jim Rossignol is a games critic for Offworld, an editor at Rock, Paper, Shotgun, and the author of the fantastic This Gaming Life: Travels in Three Cities. A full-length interview with Rossignol appeared on BLDGBLOG in May, and he has written a previous guest post, Evil Lair: On the Architecture of the Enemy in Videogame Worlds].

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Blogger Kenneth said...

Architects should know C++ at a high level

August 28, 2009 1:03 PM  
Anonymous cm2m said...

The post raises really interesting questions...

thanks and greetings!

August 29, 2009 12:30 AM  
Anonymous Anticitizen said...

The image of the purple translucent builds is evocative of William Gibson's description of the matrix in 'Neuromancer' as a virtual city that represents data, complete with glowing skyscrapers made of light.

August 29, 2009 8:32 AM  
Anonymous Anticitizen said...

And by 'builds' I mean 'buildings' of course... or perhaps bldgs...

August 29, 2009 8:33 AM  
Blogger TwilitePrincess said...

This comment has been removed by the author.

August 29, 2009 9:15 PM  
Blogger TwilitePrincess said...

(Previous post removed due a typo, I am an incurable geek.) Fascinating post, Jim. The information on Viktor Antonov’s and Marco Corbetta's cities was a revelation to me, and the concept of procedural destruction. As a non-gamer, I have much to learn, but have found the architecture of games, films and comics compelling.

I wonder if space syntax could be a useful model to add to the mix, if one wanted to test how these fascinating cities would actually work. For example, one could use spatial syntactical mathematics to calculate traffic patterns, as well as the quantity and quality of social relations, commerce, and other sociological and psychological factors, such as malaise or anomie. Space syntax has been used to predict divorce, crime and suicide rates.

It could be interesting to add disciplines such as psychogeography, spatial analysis, neuroscience and others to game design, to better understood the complex ways in which cities organise and function.

August 29, 2009 9:22 PM  
Anonymous Steerpike said...

You can always count on Jim Rossignol for a a thought-provoking and erudite piece of work. Thanks, Jim - I thought your discussion of this topic was great.

At the risk of shameless self-promotion, one of my writers at the Tap-Repeatedly blog wrote a similar article a while back. Some readers here might find it interesting: http://tap-repeatedly.com/?p=3075

Thanks for the great work, Jim.

August 31, 2009 10:05 AM  
Blogger Econniff said...

TwiP, you bring up a good point - that the in the near future, games are going to need to seek the help of more than just architects if they intend to built convincing procedural (or even designed), living cities

August 31, 2009 4:19 PM  
Blogger mark said...

when i become a billionaire i'm going to recreate a legendary video game city in the IRL.

August 31, 2009 7:36 PM  
Blogger Christopher said...

Kenneth said...

"Architects should know C++ at a high level"
Thanks for the pointer.. I'm soon to be a student in Arch, and was considering learning a more complex computer language than the BASIC i was taught in 5th grade.

Another game to look at was "True Crime: Streets of LA" it recreated 240 square miles of LA with extreme accuracy for and early PS2 release

September 01, 2009 12:09 AM  
Blogger Chris Gannon said...

nearly a year later...

The website for Chris Nolan's newest movie, Inception, holds an interesting 'mind-crime' game where a city grows around a user generated path. This then becomes the landscape in which your character must sneak around and collect prizes.

http://www.mind-crime.com/

worth a look, relevant to the discussion, interesting to see web based games take on city planning. We may be closer to The Singularity than previously thought...

May 17, 2010 5:31 PM  
Anonymous Anonymous said...

Great article!

August 18, 2013 10:54 PM  

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