A Piece Of Place

A PIECE OF PLACE Modeling the Digital on the Real in Second Life C. ONDREJKA Linden Lab, USA

Abstract. Digital worlds exist as synthetic models and have no need for the constraints of the real world. This freedom allows digital worlds a vast design space of representational choices, ranging from near correspondence to the real world to complete abstraction. The digital world Second Life was designed to allow its residents enormous creative freedom and to be as broadly appealing as possible. Second Life chose to mirror the real world in many important aspects in order to provide a place that felt familiar and comfortable, while granting freedoms not possible in the real world. This Article will cover the environment of Second Life, the reasons for the choice and the challenges that arose.

1. Choices Digital worlds have been imagined in many forms, from the “lines of light” of Gibson’s cyberspace (1984) to the real world of Stephenson’s “Street” (1996). Freed from the limitations of real-world geometry and physics, digital worlds can choose any topological, representational or physical rules that they want. The forty-odd years of networked gaming and digital worlds indicate that many options were explored (Koster 2002), from early examples that used text and hyperlinked worlds through space simulations with graphics and physics, all the way to Second Life’s simulation of real world rigid body dynamics, fluid flow and visual appearance. Launched in 2003, Second Life is a digital world unlike any other. It was designed to allow residents to control nearly every aspect of their world. From the shape of their avatars to the design of their homes, from how they spend their time to what types of affinity groups they form; Second Life’s design was focused on fostering creativity and self-expression in order to create a vibrant and dynamic world full of interesting content. One of the most important sets of decisions involved the design and presentation of the world itself. Built upon a unique grid and streaming architecture (Rosedale and Ondrejka 2003), Second Life’s technology is uniquely suited to the requirements of user creation. These requirements were to make the world user-created while still maximally interesting and approachable for new users, to foster community and to scale smoothly with population growth. A digital world that mirrored the real world was chosen because it provided the best solutions to these diverse requirements. Before delving into the requirements, some background on Second Life is needed.

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2. The World of Second Life Second Life is a continuous and persistent world that attempts to model the surface of an Earthlike world in a reasonably life-like way. The sun rises and sets, objects fall under the effect of gravity, trees and grass blow in the wind and clouds form and drift. Second Life runs on a grid of computers with each one simulating approximately 16 acres of land and the airspace above that land. The computers are also running a full rigid-body physical simulation of the all of all the objects on and over the land, a simplified solution of the NavierStokes equations to simulate the motion of the wind and streaming routines to send all the data needed to view the world to anyone who is connected (Rosedale and Ondrejka 2003). Each computer is edge-connected to up to 4 other machines, allowing objects and visibility to seamlessly cross between machines, resulting in a perceptually continuous space. One could, for example, choose to travel across the entire world (Au 2004). This trip would take you some time, as the world of Second Life is already large and is currently growing at a rate of 300 - 500 acres per month. The current world is show in Figure 1.

Figure 1. The world of Second Life on June 4, 2004

Each of the grey-outlined squares represented in Figure 1 is a single computer. Currently approaching 200 machines, Second Life covers over 3,000 acres of space. This topology allows new land to be added easily as required by population growth. In addition to the land, nearly a million independent primitives are also being simulated by the system. Primitives are the building blocks of Second Life and allow residents to create anything that they imagine. Using a constructive solid geometry approach (Ondrejka 2003), residents create collaboratively in world, in real time. Residents of Second Life participate in a wide variety of activities, from building homes and holding parties to entrepreneurial activities of all kinds. Multiple universities have sprung up in

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order to educate the population about the world. Several groups are raising virtual currency in order to auction it for real-world currency and then make donations to non-profit groups (VERTU 2004 and Lindens for Life 2004). Residents currently engage in hundreds of thousands of playerto-player transactions per month, generate over US$40,000 in real-world wealth per month through the auction of virtual currency and spend tens or hundreds of US$ per month in order to own virtual real estate within Second Life. Armed with an understanding of Second Life, it is time to delve into the reasons for modelling it on the real world. 3. Like the Real World, Only Better So why model a digital world on the real world? Given the enormous computing power of the Second Life grid, virtually anything would have been possible. However, the goal of a usercreated world made it clear that modelling on the real world – with improvements – made the most sense. 3.1 THE NEED FOR USER-CREATED CONTENT

Residents of digital worlds consume content at an incredible rate. With the rising costs of content development, developers have turned to several options to reduce these costs. Massivelymultiplayer online role-playing games solve this problem by limiting the rate of progress through the game, but this approach doesn’t apply to a more generalized digital world. Instead, Second Life utilizes the incredibly energy and creativity of its residents by making creation a fun and integrated part of the experience. This constant generation of new content keeps the world dynamic and fresh and helps to retain residents over long periods of time. More importantly, as user create and learn from each other, the overall quality of content created in world increases. New users learn better approaches to building, get to play with everimproving gadgets, can wear the latest fashions and ultimately pass on their knowledge to the next batch of new residents. 3.2 THE MOTIVATIONS OF PLACE

While user-created content provides a solution to content generation, providing context and motivation is critical for producing content that is appealing to both the creator and to others. While economic factors provide one source – and have been discussed elsewhere (Ondrejka 2003) – the real-world sense of place is another important source. Residents entering Second Life have a great deal of experience in the real world and artistic and narrative forms derived from it. While exceptions exist (Gibson 1984), even speculative fiction and movies tends to owe more to the real world than to more abstract forms. Place has meaning. Up and down has meaning. Most people look more or less human. By providing a digital world that allows its residents to build upon this massive well of cultural knowledge, Second Life offers enough familiarity to not baffle new residents and creators. It can still be challenging, as the multiple digital universities indicate, but it is sufficiently familiar to allow new users to incorporate themselves into the community. The real world also provides a rich source of entrepreneurial ideas. There are certainly business proposals that don’t have real-world analogues, but residents’ freedom to leverage the vast range of real-world business allows those residents who choose economic motivations to engage in a fluid, rapid evolution of ideas. These residents can then further borrow from the real world, because they understand that location, customer traffic and advertising all apply within Second Life.

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Travel in Second Life occurs in one of several ways. Your avatar can walk over the terrain; fly like a superhero; utilize land, sea or air vehicles; or utilize the telehub system. Telehubs are the public transportation system within Second Life and allow a resident to teleport from one location to another. However, rather than arriving directly at the destination, they instead arrive at the telehub and can then walk or fly the remainder of their journey. Telehubs provide a place for residents to meet each other, locations for announcements and, most importantly, create nonuniform land value. Land near telehubs receives more traffic and is easier to reach. It would be more valuable for someone setting up a shop. On the other hand, a private retreat should be on land as far away from telehubs as possible. The exclusion of random point-to-point teleports is an important component of giving place meaning within the world and allows telehubs to act as population and commerce centers as the world expands. The ability to build vehicles that make travel more interesting also has created a market for vehicles of all kinds, from balloons to motorcycles. Skydiving has become a popular pastime and many different types of vehicles have been invented to support that activity. The tabula rasa of new land has also proven to be a powerful motivator. Second Life computes a full rigid-body simulation of the world, but when creating, residents are free to ignore most real-world physical constraints, such as gravity and collision between objects. In addition, since virtually no creation or duplication costs exist, the only significant limiting factors are user creativity and time. This allows creation to be an incredibly expressive process and leads to residents who want to build in the digital world what the real world denies them (Au 2003). Empty land calls out for a park, a home, a game or a business, and residents, unencumbered by the economic and physical limitations of the real world, realize that they can create all of these. 3.3 COMMUNITIES THAT GROW

Residents use digital worlds in diverse ways. Communities improve many of these activities, and the topology of Second Life allows groups to work together in very real-world ways. Users who find that they enjoy spending time together can decide to build homes near each other or to work together to create a central meeting place. Merchants who have complimentary needs can work together to create shopping destinations. For example, several casinos have popular clothing stores associated with them so that patrons can look their best. Affinity groups can work together over large areas and time periods. Many group builds extend over a full simulator (16 acres) or more, resulting in large themed areas. These large areas, with their consistent appearance and goals, also result in destinations for new users who are looking for specific activities within the world. By actively recruiting new residents, groups build their knowledge and skills, resulting in further improvements to the world. This feedback has led to residents often pioneering new ideas before the developers. The collaborative nature of the world also allows groups to form in very ad hoc ways. Residents meet each other at open houses, classes, while acting as the “Welcome Wagon” for new users and while creating. All of these activities take place within the shared space of the world and others can generally observe and join quite easily. When combined with the tendency of most users to create in a very self-expressive manner, this leads to residents having a much more complete picture of each other than in other online forms, such as chat. The real-world context also helps the community context, as many activities are immediately recognizable by new users.

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3.4 SMOOTH SCALING AHEAD

Modelling on the real world also enables Second Life to have excellent scaling properties. Each individual machine is only connected to a maximum of four other computers, no matter how large the world becomes. If Second Life had chosen a more abstract model that allowed machines to connect to more than four neighbours, the hub machines could easily become overwhelmed as the world grew. Instead the grid expands smoothly as the world grows. The mapping of land to machines also allows the economics of land ownership to correctly manage expansion. Each new machine adds 16 acres of land to the world, which is purchased by the residents. By monitoring the amount of land users own and what they are paying each other for it, the rate of expansion can be accurately controlled. In addition, selling land directly to residents provides a powerful alternative to the traditional subscription-based revenue models of online games. 4. Real-World Challenges Modelling on the real world, combined with Second Life’s size and complexity, has resulted in some challenges. The most important challenges related to place are navigation and zoning. Navigation is difficult because on top of the normal challenges, the world is incredibly dynamic, so landmarks vanish, people move to new locations and stores change inventory with much greater frequency than the real world. As the world grows, this will continue to be a problem. Currently, Second Life relies on a combination of searchable descriptions, tracking of resident movement patterns and a rotating list of points of interest to reduce the problem. Zoning has also transferred from the real-world. Second Life only imposes two types of zoning on its users, Rating and Safety. 16-acre regions can be rated either “PG” or “Mature” in order to limit what types of adult activity and content take place within them. In addition, regions can be “Safe” or “Unsafe”, which determines whether player-to-player combat is allowed and whether or not your avatar can die. As expected, residents would like additional zoning options and the ability to enforce their zoning decisions on other users. While those features have not been added to the system, some groups of users have managed to purchase enough land to create and manage their own zoning rules. 5. What’s Next? Second Life has been live for about a year and has just scratched the surface of creating place within a digital world. As the representational fidelity and population increases, what new uses will residents find for Second Life? With nearly a dozen university classes from disciplines as diverse as urban planning and game design having used Second Life, will broader education and research be next? Will the rapid prototyping potential be leveraged by architects, social scientists and augmented reality researchers? Modelling Second Life on the real world has led to a broadly appealing digital world with an incredibly diverse set of residents and behaviours. These residents, their creations and their communities are a deep vein of knowledge and creation waiting to be mined. References Au, WJ: 2003, Home for the Homeless, at (last visited on June 6, 2004)

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Au, WJ: 2004, The Trek Begins, at (last visited on June 6, 2004) Gibson, W: 1984, Neuromancer, Ace Books, New York. Koster, R: 2002, Online World Timeline, at (last visited on June 1, 2004). Lindens for Life: 2004, Lindens for Life Homepage, at (last visited on June 6, 2004) Ondrejka, C; 2003, Escaping the Gilded Cage: User Created Content and Building the Metaverse, at (last visited on June 1, 2004). Rosedale, P and Ondrejka, C: 2003, Enabling Player-Created Online Worlds with Grid Computing and Streaming, at (last visited on June 6, 2004) Stephenson, N: 1992, Snow Crash, Bantam Books, New York. VERTU: 2004, VERTU Homepage, at (last visited on June 1, 2004)