A REPORT ON VIRTUAL WORLDS



Virtual Worlds

Sree Vardhani Malladi and Linh Ngo

March 1, 2008

Introduction 2

Architecture of the Virtual Worlds 3

Physics Engine 4

Avatars 6

Architecture of avatars 6

Fig 1: Layers of Avatar Architecture [8] 7

Communication 8

Text 8

VoIP 8

Different Virtual Worlds 9

ViOS 9

Active Worlds 11

There 12

Entropia Universe 13

Second Life 14

Scripting Languages 16

Different social networking 17

Consumer Standards Rating 17

Gaming Standardizaton Efforts 18

Gaming Conferences 19

Useful websites 19

References 19

Introduction

The word "VIRTUAL" is often heard in the present day computer world in context with "Virtual reality", "Virtual world".  Virtual reality is a technology for users to interact with a computer simulated environment, really or virtually. A virtual world is defined as a computer-based real world simulated environment for its users to inhabit, wander, play and interact using virtual humans or characters called avatars. These worlds are represented in the form of a two-dimensional or three-dimensional graphical representation of the real world, with the built-in real world regulations like movement, actions, communication, physics etc., [1]

Over the past 10 years Virtual communities have been growing progressively. The sophistication and realism of shared virtual worlds has grown from bulletin board systems to Multi-User Domains to virtual environments. Multi-user virtual worlds have been able to launch themselves as viable commercial entities. [3]

Virtual worlds commonly are also known as “digital worlds” or “simulated worlds” or “Massively Multiplayer Online Games (MMOG’s) “. [6] These three-dimensional worlds are virtual spaces where multiple users can reside and communicate with each other in an online virtual environment. Virtual real worlds are focused on hundreds and even thousands of simultaneously occurring processes that are not obligatorily interconnected. Sounds, animations, hi-resolution textures and hi-poly meshes produce a realistic atmosphere or environment that resembles realistically the real world in great detail. [2]

In order to join and surf any virtual real world community it is necessary to create an avatar that will represent the person virtually in that environment. We can change the appearance of the avatar, in the way we want, depending on the accessibility of that virtual world. And then the avatar can move around that world communicating with other users through personal messages text and/or voice communication. Users may choose different roles provided by a particular virtual real world. For example, building a hospital scenario, this may help many people to communicate with doctors virtually in the order to solve the problems.

All though not all, but most of the virtual worlds allow multiple users. Few examples of the virtual worlds which allow multiple users include Second Life, City pixel, There, Active Worlds, Entropia Universe.

Virtual real worlds provide a unique opportunity for people to demonstrate their abilities, to share their experience, knowledge and emotions with other people in a virtual environment recreating specific conditions. Like for example a university with the same streets and buildings, a city with the same routes and land marks etc.

Most of these virtual worlds facilitate global interaction between people by providing the space for multi-user scientific conferences, business/design meetings, online trade, shows, workshops, social networks, and other events. They also provide several services like entertainment, education, design, maintenance, communication, simulation, training, commerce, etc.

They have the ability to recreate various environments ranging from virtual shops and hotels to fantasy worlds created by human imagination. The applications of virtual real worlds are numerous which include virtual offices, online classrooms, virtual factories, virtual museums/art galleries, etc. [2]

The better part of currently existing virtual worlds is that they not only spotlight on the gaming and entertainment division, but also are concerned in using them for official meeting (virtually), Advertising etc. Now- a-days virtual three- dimensional worlds are also developed for many other different purposes like gaming, education, socialization, online community, military training, and social networking.

The advantages of a virtual world are that it is great and realistic user experience. It is feasible to create any avatars in any fashion with any desired name, it support multi-user environment which helps in easy interacting, and multiple separate groups can work together with each other (if required). Communication is world wide and is clear. Concurrent processes and actions can be done at a time which will not necessarily affect other in world users. [2]

In general all the virtual worlds have few common features that include shared space, Immediacy, Interactivity, Graphical user interface, socialization, persistence, Plat from independence. [6]

In virtual worlds multiple users can share the world at once in real time. The virtual worlds need to be platform independent for ease of access by any of its user. The level of interactivity has to be very high, for all the virtual humans to communicate, build and script with very little effort.

A small amount of virtual worlds have the flexibility to build, edit, change the scripts in order to change the objects, actions, behaviour, appearance etc. Independent of the fact that the user is logged in or not the world exists. These worlds support the development / construction of the in world universities, offices, play areas, houses, colonies, etc. These virtual worlds depict space visually from two-dimensional to three-dimensional range. [6]

A small number of virtual worlds are so close to the real world that they have in-world currency. One can build or create objects and trade them for riches or other objects. Some virtual world currency can be converted to real world currency even, for instance Entropia Universe. Cash in second life is called as Linden Dollars.

The architecture of the virtual worlds are developed keeping in mind the true world set-up, so that the real world is simulated at ease and is represented precisely in the virtual environment with out much variation. The appearance of the avatars, buildings, objects and furthermore even the way the avatars behave as in walking, running, jumping, flying, voice/text communications are all characterized analogous to the real world.

Few virtual worlds even endow with currency in order to buy or sell objects that are created by other members in the world. These objects may comprise of guns, equipment, vehicles, ornaments, clothes, buildings, etc.

Architecture of the Virtual Worlds

The fundamental architecture of most all the Virtual worlds in general has a built-in physics engine which helps the users to create objects just as they appear and behave in the real world. Although an average computer user may not have had ample exposure to shared virtual environments, the presence of these environments on the Internet is growing rapidly, due to simplicity of access. For instance, the virtual world Entropia Universe is built and inhabited by over 6, 80,000 people.

For the virtual worlds to evolve into true communities the architecture of a shared virtual world was developed keeping in mind the four main key constraints: reasonable economic model, Low Latency for world Synchronization, a friendly environment for users, and affords of social interaction [3].

The first goal is supported by examining economic issues related to the design of commercially viable 3D virtual environments including issues such as allowing use of currently developed Web based content. The second goal is supported by underlying network support that combines a mixed set of Internet protocols and a mixed model of a central server for universal resource management and multicast based transaction distribution. The final two goals are supported through architectural design patterns and a literature review of social issues and personal representation in virtual worlds. [3]

Physics Engine

“A physics engine is a computer program that simulates Newtonian physics models, using variables like mass, velocity, friction and wind resistance. It can simulate and predict effects under different conditions that would approximate what happens in real life or in a fantasy world. Its main uses are in scientific simulation and in video games.” –

In general the software uses this physics engine to improve the way it mimics the real world setting, to build a new virtual dream world or to construct highly realistic games, animations, universities etc., [4]

It is the first step of the plan to march into the game industry, to start with building modular distributable building blocks, with the help of a physics engine. In addition to their use in scientific simulations and animation movie generation Physics engines are increasingly relevant to more and more video games, virtual worlds, and virtual reality applications. The physics engine gives us the ability to reach unprecedented levels of realism in modeling physical rules of the real world or arbitrary imaginary worlds, letting us to focus on the logic of our application, weather it is a game or a simulation program. It facilitates even in eliminating the pause in the display. [4]

The real world actions are characterized very accurately. For example the gravitational force that acts on a person, in Second Life, when an avatar tries to land abruptly after a flying the avatar hits itself to the ground, instead of instead of standing still. Building vehicles, buildings, trees, all objects depend on the physics engine for their appearance and behavioral/physical properties.

Consider the virtual environment of second life, if an object rests on the floor without any movement for few seconds, then that object become stationary and the physical actions are disabled. It remains stationary until a collision occurs with some other physical object .This impact reactivates the physics processing for the object.

At the beginning when the physics support characters were developed only rigid body dynamics were used as they are faster and easy to calculate unlike modern animation games which need soft body dynamics that need to allow the flexibility. These soft body dynamics are used for clothing, textures, liquids, particle effects etc., For example in the ‘Entropia Universe’ with the constant use of the clothes they to tend ware out after a certain period of time. Physics engine is also used to decrease the lag in the movement of the avatar. At times to display the movement of the any liquid, explosions in air, flow of fire etc., some form of fluid dynamics simulation is also provided by the engine. [1]

The precision of the numbers representing the objects and the forces that are acting on it are the primary limitations of a physics engine. Errors may occur in calculations if the precision is too low, due to round-offs, causing the object to over shoot or undershoot the exact position. When two or more free-moving objects are fitted together with the accuracy greater than that of the engine such errors may occur. “Higher precision reduces the positional /force errors, but at the cost of greater CPU power needed for the calculations”. [1]

Frame rate (the number of moments in time per second) is another unusual aspect of physics precision. Each frame is treated separately and the spaces among the frames are not calculated. For example consider the situation where the small fast moving object does not move smoothly, this is due to low frame rate. At such times it looks like that object is teleporting from one point to another instead of smooth movement. One can unravel such problems with the help of a better physics engine. [1]

There are few visual issues which need to be solved in the present beta issue of the Second Life. For instance when a bunch of objects are stacked over one another there, a small gap is visible between the objects instead. There are many other issues that are to be solved. The new Havok 4 physics engine of the Second Life has promised the virtual world with fewer crashes, less lag, better tangibility and better overall physics. [6]

A Wiki for the Havok 4 beta is established for all the users to inform the Linden Labs about the working issues of the new engine. And they have got office hours for Havok 4 engine for the clients who wish have profound knowledge, ”Tuesdays at 9pm PDT and Thursdays at 8am PDT”. One can inform about everything they find using the Public Issue Tracker at "Issue Tracker" to the Linden Laboratories. [7]

The issues that are already know with the havoc 4 engine are sitting on the top face of the box will fail, the karts stop too quickly and tumble very easily while going over bumps, there is not spin for few Target Omega physical objects, the object starts rotating when it is made non-physical while it is rolling, sitting avatars do not always contact seat, script does not work properly for short range teleporting, script for the flocking birds acts in a different way in this engine, for instance they acquire high energy overtime and rocket out of sim, few complex vehicles demonstrate inappropriate behavior ad may collide with phantom rings, tubes etc., the avatar direction does not update for other users(if Avatar 1 turns, Avatar 2 cannot recognize that unless the avatar 1 does something like running, walking, flying, jumping etc.,) , on uneven ground physical spheres sink to ground, an object which is completely sink into ground cannot be fetched back, when a large cube is dropped over a smaller ones, they interpenetrate when they should not, after several minutes of flying and turning the C-Tech 2050 hover ship spirals out of control. There are few more concerns about the Havok 4 engine which are being worked on. [7]

The Second Life competitor Entropia Universe uses the Gamebryo physics engine .In the recent days the Entropia Universe decided to update their physics engine to the high tech game engine CRYTEK-2. This is in idea of making Entropia Universe “closest-to-reality looking massively multiplayer online game ever seen". The switch to the new physics engine is estimated to be finished and available to all its users by mid 2008. All the users of this virtual world are really excited to play with the updated engine.

Features of this new Cry ENGINE 2 include: Real Time Lighting and Dynamic Soft Shadows; Volumetric, Layer and View Distance Fogging; Terrain 2.5D Ambient Occlusion Maps; Normal Maps and Parallax Occlusion Maps; Real Time Ambient Maps; Subsurface Scattering; Eye Adaptation & High Dynamic Range (HDR) Lighting; Motion Blur & Depth of Field; Light Beams & Shafts; High Quality 3D Ocean Technology; Advanced Shader Technology; Terrain LOD Management Feature; Integrated Multi-threaded Physics Engine; Character Individualization System; Parametric Skeletal Animation; Procedural Motion Warping; High Quality Animation Compression; In Game Mixing; Data-driven Sound System; Interactive Dynamic Music System; Environmental Audio; Dynamic World Sounds.[9]

Other virtual worlds like “World of WarCraft” use the WOW- Engine, “ViOS” (Visual Internet Operating System) uses the ‘Proprietary engine’, and “Active World” uses ‘Render ware’. There are different computer games that use the Physics Engine. For instance, “Counter Strike” uses the much modified version of the ‘GoldSrc’ engine; “Age of Empires III” uses the ‘Havok Game Dynamics Engine’, “Real-time Strategy” uses the ‘Havok Engine’, “Company of Heroes” use the ‘Essence Engine’.[1]

Avatars

As already mentioned an “Avatar” also known as virtual humans are the only source to surf in any of the virtual worlds. Avatar is an animated character that represents a person in the three-dimensional virtual world. Appearances of the avatar can be changed depending up on the interest and the available objects, textures, clothing fashion, colors. The avatar may be fat, slim, short, tall, have any color hair red, blue, green, yellow. Can wear anything, can go and browse any wear, build anything depending on the access permissions of the land.

These avatars are used for explaining the physical and behavioral aspects of the real human beings. For instance, to hide for enemies (in case of war world simulation) by running, walking, jumping, crawling etc.

Knowledge about various disciplines like kinematics, artificial intelligence, computer graphics, computational geometry, and bio-mechanics is required in order to develop an apt virtual human. [8]

Architecture of avatars

An avatar was designed with some basic architecture in order for it to behave like a real human being. There are several ways of designing architecture of a virtual human. One way of a way which is not specific to a single virtual world can be as following.

Different layers of the architecture of an avatar include Cognitive layer, Behavioral layer, Physical layer, Kinematics layer, Geometric layer. The basic layer is the geometric layer. This layer deals with the definition of a virtual human and its appearance. The next layer is the Kinematic layer. At the this layer, the virtual human is represented as a set of rigid bodies, called ‘segments’, and is hierarchically organized and connected by ‘joints’ and the fundamental animation is done. The third layer is the physical layer, in this layer the animated humans are combined with the physics and complex animations are done. The behavior of the avatars (like actions, expressions) are represented in the subsequently layer known as behavioral layer. Then the stimuli with reasoning process to search for suitable action of the virtual human are represented in the cognitive layer. Acquiring the knowledge and the look for appropriate action are all taken care in this final cognitive layer. [8]

[pic]

Fig 1: Layers of Avatar Architecture [8]

This virtual human software architecture helps anyone to develop an interactive virtual human with a clear division of the physical, kinematical, geometrical behaviors of a human. There are three engine modules in the architecture of the virtual human. They are the behavioral engine, Execution engine, Presentation engine. [8]

The Behavioral Engine: The virtual environment events and the actions to be performed by the virtual human are sensed in the behavioral engine. This engine specifies the actions to be performed by the avatar in terms of finite state machines. Given a specific state this engine senses the events, identifies the applicable transitions, if required activates one or all of them and sends it to the Execution engine the list of actions in order corresponding to a transition. [8]

The Execution Engine: The kinematic, physical and geometric layers are taken care in this engine. The animation actions sent by the behavioral engine are identified here and information is retrieved. The execution engine two types of animations namely pre-stored animations, parameterized animations. The object information, information on the topology of the environment, parameters given by the user can be used for modeling the animation model. [8]

The Presentation Engine: Textual information is presented to the user using this engine. It can format the given textual information to adapt the visualization according to the display. By taking into account the distance between virtual human and the user it can control the voice volume. [8]

The clothes, skin texture, personality, accessories, hair color, all the parts of the avatar can be changed or edited accordingly. When we first create an account, all the avatars are given one basic dressing, personality, hair color etc (for same gender).

[pic]

Fig 2: Snap shot of the In-world avatar of the virtual world Second Life.

For instance an avatar in Second Life looks as in the above figure. Here the clothes, hair color, of the avatar were changed. In this snap shot an avatar is sitting over a basic chair taken from the inventory.

All the building, creating, editing is done with the help of the virtual human (avatar). A building was build with the help of the basic objects and the chairs were placed in it by avatar.

Communication

The main attraction of the virtual worlds is the communication provided by them. All its users can communicate with each other as they do in the real world. This communication can be of either ways like Text or Voice.

Text

Communication was over text till the recent years in virtual worlds. It’s just like any other text messaging where one member can send messages to other or near by member. I range of the messaging differs from a virtual world to another virtual world. There are two main methods of text-based communication: local chat, and global "instant messaging", within Second Life.

VoIP

Voice communication in virtual worlds is done via VoIP. VoIP stands for Voice over Internet Protocol. It carries telephony signals as digital audio encapsulated in a data packet stream over IP, reduced in data rate using speech data compression techniques. [1] The range of the voice message also varies from a virtual world to another virtual world. This voice messaging can be enabled or disabled in world.

In second life, the environment prompts you whether you want to enable or disable the voice chat at the time we enter the world. We can even customize the chatting in the virtual worlds. Chatting is used for public localized conversations between two or more avatars, and can be heard within 20 m. Avatars can also 'shout' ('audible' within 100 m).

This feature of the virtual worlds promoted them a lot for online meetings, e-learning, advertising, e-business etc. The reason is one virtual human can communicate to any other one as in a real world, they can talk to each other, teams can discuss. For instance, consider the online teaching system (E-learning), the virtual worlds make it easy for a virtual class room arrangement, just like a real one. And students from various parts of the world can sit and hear and communicate as they do in a real world class room. The voice communication helps for ease of understanding and interacting for questionnaire or doubts.

Different Virtual Worlds

Different virtual worlds that are popular present day are Second Life, Entropia Universe, World of Warcraft, There, Visual internet operating system, Active worlds, etc. Few worlds are gateways for online interaction, few are for entertainment and for making money in the real world, and few support academic purposes.

ViOS

One of the very beginning virtual worlds was the ViOS. It stands for Visual Internet Operating System. It is a client server system build at ViOS Inc. in mid 1990’s, designed by Julian Lombardi. This is a massively-scaled multi user three-dimensional virtual environment which can be accessed with the help of avatars, which can be modified too. Like any other 3-D games this has all the necessary graphics, textures etc. [1]

Taking the virtual world of the complete Internet and physically represent it in large virtual landscape with mountains, rivers, neighborhoods, cities was the basic concept behind this “ViOS 3D Internet Viewer”. And the idea is to access to rich content available in the internet at ease. Its users can travel to cities/areas of interests through 3D portals; maps etc., Objects in these worlds generally point to the deliverable resources of the world-wide web. [1]

[pic]

Fig 3: Starting point where the users enter the ViOS world. (Courtesy )

For example if you want to surf for some humor sites for entertainment, type it in or click in the find menu. This will take you to the area where there are present. Similarly if you want to go shopping, type in shopping or click it on the find menu. It will then take you to the specific area for shopping. Again here you can search for the items you want in the stores and access them and take you to the retailers menu. After finishing it you will return to the landscape. [10]

Fig 4: In-world Snap shot of the ViOS world pointing to a humorous website

Platforms that support this virtual world include windows (95/ 98/ ME/ 2000 SP4). Its beta version was released in the year 2000 and public release was in the year 2001. “Proprietary” engine is used for the physics. It can be either single or multi user platform. It can be either downloaded or can be run with the help of a CD. The basic system requirements are 64MB RAM, 16 MB AGP graphic cards, 150 MB HD space for disk cache and 56 kbit/s Internet access. Inputs can be via keyboard, Mouse.[1]

At the beginning this world was started with 420 cities and communities that appeared as navigable 3D locations. But due to lacking resources, the dot com bubble and lack of investor interest in continuous financing, the company was unable to market or maintain the server’s infrastructure anymore for its active users. [1]

Active Worlds

It is a 3-Dimensional virtual world whose original goal was to be the 3D-equivalent of a 2D web browser. Instead of creating a website, the user could construct an office, building, or area in which to display products or information. It was released in the year 1995 (beta version) and was public in the year 1997 and the current 4.1 version was released in the year 2006. This browser runs on windows and also on Linux (but with little complicated steps).[1]

Once can enter into active worlds in either of the two ways: a free tourist or a paid citizen. Tourist mode is a free version and allows accessing only limited functions. Where as a citizen can access all the functions and can even buy lands in the world. Citizen ships costs around 6.95$/month or 69.95$/year. A tourist user name can change every time they log in unlike a citizen user name.[1]

Users own environment can be created with building. It uses the Render ware scripting for building its objects. Other than citizens even tourists can build their building but they will be deleted by anyone. A land claimed by one user can not be encroached by other users. The object may also be transformed into another object, by typing in the name of the desired object. And an object can be moved, rotated. It can be duplicated and moved to a new position.

[pic]

Fig 5: Screen shot of Active worlds – courtesy

Communication is with in 200 meters from other people for chatting. Private messages can also be sent to near by person by whispering the messages. The scripting of this world is also very understandable as it has direct commands.

It was developed, designed and published by Active worlds; it uses the Render ware engine. Platforms on which it can run include windows (browser), Windows, Linux (Server/SDK). It can run on both graphical chat and building interface mode. The media of download is Client Download. The system requirements are 300 MHz (800 MHz recommended) CPU, 128mb+ RAM, windows (98, Me, 2000, XP, or Vista). Direct X 8.1 or later Windows Media Player 6.4 or later, 3D acceleration (64mb + video RAM recommended). [1]

There

“There” is 3D virtual world was developed by There.Inc, in the spring of 1998, which was later taken by Makena technologies. It has 14 major islands and numerous numbers of smaller islands. [1] This world mainly focuses on networking with people.

In this virtual world one can create a 3D avatar, chat with text or VOIP, meet friends, play games, create your own line of virtual products, build a dream home. Similar to second life the hair color, style, head, body shapes, skin and eye color, clothing etc., can be changed as wished. Unlike other virtual worlds like Second Life; avatars in THERE have numerous facial expressions.

It has two types of memberships for logging into it; a basic membership, a premium member ship. Basic membership is free for registering, can listen to streamed radio and can join 20 groups, but does not support voice chat. The premium membership has a fee of 9.95$, voice chat is available, can join 30 groups and can create own host events, can post in forums and your own neighborhood. [1] The name of the member remains the unique every time for all the logins.

[pic]

Fig 6: A place where new members log in – courtesy

The objects created in “There” can be traded for ‘Therebucks’ (In-world currency of the virtual world). Therebucks can be purchased directly from There, from other members, or from any of the third party online banks, which usually offer competitive exchange rates. Monetary transactions in There's economy are done using Therebucks, virtual currency with real world value. Members can also sell their Therebucks to banks in exchange for real world currency, usually with US dollars.[1]

But this world does have any built in scripting language to modify the objects created, and does not support any external software to link with this world.

Developed, published and distributed by Makena Technologies. The platforms on which it can run are Windows (98/ ME/ 2000/ XP/ Vista). Vista is supported partially. It was released in the year 2003. The system requirements include 256MB RAM, 56k Internet connection (Broadband connection is highly recommended), 500MB free hard disc space, Internet Explorer XML supported (Not compatible with IE7), and approx. another 500MB for as disk cache for in-world 3D content. The input methods can be via keyboard or mouse.[1]

Entropia Universe

Entropia universe is a massive online Virtual Universe designed by Swedish company MindArk. Although it shares elements of regular MMORPG’s (Massively multiplayer online role-playing game), in skill and special items, it is not officially categorized as one. And there are no strict levels within the Entropia Universe.

Entropia universe does not any subscription fees. Instead it consists of buying in-game currency in this universe is termed as ‘Project Entropia Dollars’. 10 Project Entropia Dollars make $1 US dollar.

[pic]

Fig 7: In-world snap shot of Entropia Universe

The visual character creation in this universe is really very clear and highly detailed than any other virtual world. The avatars are created and can be modified similar to that of Second Life. Some qualities that can be changed include the fitness, size, color of the body, hair color, style, size etc.

The service can be downloaded and free for play, and then an account registration procedure is followed with it. When someone new first starts playing they are not given any items or clothing except for a damaged orange jumpsuit and a pair of black shoes. Although one can participate for free, more involved game play is difficult without depositing funds. [1]

Players with little or no money are initially limited to the following actions: Using the service as a 3-D virtual chat room, exploring the virtual universe, collecting "fruit", "dung" and various precious rare stones which can then be sold to other players to raise funds. [1]

Using an in-game process called "Sweating" or "Sweat Gathering" where one spends time using in-game "Mind force concentration" abilities on creatures to extract bottles of "Vibrant Sweat", which can then be sold to other players for variable project entropia dollar values. Performing numerous "jobs" for other players; for example, acting as a trader, selling other players' virtual possessions for a profit. [1]

Participants with funds often attempt to kill and loot Entropia's tougher creatures which are often likely to yield a higher number of valuable items, or they can also participate in the "Mining" and "Crafting / Manufacturing" professions. That can also produce saleable items, to try to fund further game play. However, an element of risk and luck is involved in all of these activities, and the eventual total payback is usually less than the funds required to initially partake. [1]

Unlike second life which offers even academic opportunities inside the world, Entropia Universe concentrates more on the prospect of money making. The cultural city of 'New Oxford' within Entropia Universe offers participants the opportunity to purchase real world items, such as contemporary art and clothing. This universe does not have any scripting language in specific for the objects. Any user teleport from one place to another place instantaneously.

This virtual universe was released on January 30th of the year 2003. As of now they are using Gamebryo engine and will be updated to CryENGINE2 in the near future. According to Entropia Universe, the Cry ENGINE 2 platform will deliver the “closest-to-reality looking massively multiplayer online game ever seen”. The basic system requirements are windows (2000 or later), 512 MB RAM, 1.7 GHz CPU, GeForce/Radeon graphics card (with at least 32MB of memory). 3 GB Hard Drive space, DirectX sound device, DirectX 9.0c, Broadband connection. [1]

Second Life

Second Life is the most popular and famous 3-D virtual world present days, it needs not introduction. Second Life abbreviated as SL, was launched in the year 2003 by Linden Research, Inc., but came into attention in the recent past (2006 and 2007). It has a downloadable client and can be accessed with the help of avatars, called “residents”. Residents can explore, meet other Residents, socialize, participate in individual and group activities, create and trade items (virtual property) and services from one another. [1]

One can create an account for free at Second life. But for owning a land or for browsing some specific second life support portals, payment information is mandatory. This virtual world has its own currency, and is called as Linden dollars, which can be exchanged for real-world currency at the Linden labs (226 linden dollars make one US dollar).

A single person may have multiple accounts, and thus appear to be multiple Residents; a person's multiple accounts are referred to as alts. Player’s identity is less anonymous in this than any other virtual world, even though in-world appearance has bear resemblances to the player’s real-world look. [1]

[pic]

Fig 8: An In-world snap shot of the Second Life

The basic avatar is human in appearance, and avatars may be of either sex, have a wide range of physical attributes, may be clothed or otherwise customized to produce a wide variety of humanoid and other forms. The most basic method of movement is by foot either to walk, run or jump. And the Residents can even fly for rapid movement, but only up to 170m above terrain. Even the objects attached to the avatar can fly. There is no particular script for flying, but by clicking the fly button on the screen, one can fly (unlike real word). Communication with other residents is via text or voice messaging. [1]

With in the Second Life there are loads of cities, shopping malls, pubs, restaurants, vehicles, etc like any other virtual world. One can instantaneously move from one area to another area with in the world with the help of teleport.

Second life provides with objects that are 3D primitives for creation of any desired asset. These primitives can be stretched, rotated and moved from their position in a desired fashion. The texture (any texture from inventory can be selected) can also be changed along with the type of material (like wood, glass, metal etc) specification. The color (can be chosen from the given set of colors by combinations) of the objects, transparency (ranges in any numerical values), all can be modified. All the assets created are stored in ones own dedicated MYSQL server storage.

The world of Second Life is simulated on a large array of Debian servers, referred to as the Grid. The world is divided into 256x256 m areas of land, called Regions. Each Region is simulated by a single named server instance, and is given a unique name and content rating. Multiple server instances can be run on a single physical server, but generally each instance is given a dedicated CPU core of its own. Modern servers with two dual-core processors usually support four separate server instances. [1] Open source software technologies like Apache, MYSQL, and Squid etc are used by linden labs in order to move everything to open by standardizing the second life portal.

It uses the Havok 4 engine for its physics, and the engine is proprietary, free and open source software. The plat forms it can run on include Windows (2000 SP4/ XP SP 2/ Vista), Mac OS X, and Linux 1686. It is a multiplayer online virtual world. The system requirements include 256 MB RAM (Win, Linux), 512 MB RAM (Mac), 50 MB 1000 MB HD space for Disk Cache, 800 MHz x86CPU or better (Win, Linux), 1GHz G4 or better/Intel Core Processor(Mac) NVIDIA GeForce2, GeForce4 MX or better, ATI Radeon 8500, Radeon 9250 or better graphic cards. And the inputs can be via keyboard, mouse, game pad (which is minimum).

Scripting Languages

Some virtual worlds support scripting and some don’t. There are different scripting languages for different virtual worlds. The scripting language for the Second Life is called as Linden scripting language developed by linden labs. It helps not only in modifying the appearances of the objects but also there behavior. Entropia Universe does not have any specified scripting language. We can create objects and define there behavior but can not perform any type of scripting.

Few examples functions of linden scripting language are llGetOwner () – returns a key that is the current owner of the script, llAttachToAvatar (integer attachment) – attach to the avatar who granted the permission and do so at the point of attachment. They are many more functions in Second Life which can change even texture of the object and make them invisible.

Example Script (Second Life) – Sliding doors:

vector startPosition;

default

{

    state_entry()

    {

        //find co-ordinates for this objects current location

        startPosition=llGetPos();

    }

    touch_start(integer total_number) // executes when object is clicked

    {

        //create a vector that moves a door horizontally

        vector move=;

        vector newPosition=startPosition-move;

        llSetPos(newPosition); //move the door

        llSetTimerEvent(5);

    }

    timer()

    {

        llSetPos(startPosition);

    }

}

The ability to build and manipulate objects to create endless environments is the main feature of the Active Worlds. For the user to change the present objects, copy them, specify their locations, it has a built in object manipulation system. [11] The scripting language in the Active worlds is known as Render Ware Scripting. This scripting is more like a 3D application programming interface. This is used for rendering the virtual reality modeling languages.

Few examples commands that are used in Active Worlds scripting are Animate (Assigns animation to object), Astart (Starts an animation), Astop (Stops a running animation), Color (Apply flat color to an object), Frame (Current frame of an animation) etc., [11]

Different social networking

One interesting area where everybody is fascinated these days is the “Social Networking”. A Social Network is referred as online community with different people from various places interacting with each other. Generally these communities have active users sharing similar interests. Typical issues that impact social networking are identity, privacy, e-learning, teenage use etc. few examples of the online social networks include “FaceBook”, “Orkut”, “My Space”, etc.

Few of the virtual worlds even today focus on the social networking and groups. Almost all the virtual worlds have in world communities like restaurants, pubs, parks, shopping malls etc. these are also a means of social networking where different people interact with each other and learn about others, share interests, etc.

Second Life, There, Active Worlds all have such social networking island and areas in there virtual world. Especially the Virtual world “There” focuses a lot on the social networking.

Consumer Standards Rating

Computer games have no exact “standards” like those of normal software programs. Since they are a form of entertainment, they are evaluated similarly to the movies: an age of viewers rating and a performance rating from critics/users.

For age of viewers rating, there are two main organizations: Entertainment Software Rating Board (ESRB – ) in the US and Pan Europe Game Information (PEGI – ). PEGI is a relatively new rating system that came into use since 2003. The ways these two organizations evaluate games are quite different. ESRB is more “procedural” and PEGI is more “object-oriented.” ESRB rates games based on age appropriation: early childhood (EC), everyone 6+ (E), 10+ (E10+), 13+ (T), mature (M), and adults only (AO). Besides age category (3+, 7+, 12+, 16+, and 18+), PEGI also rates games based on game characteristics: bad language, discrimination, drugs, fear, gambling, sex, and violence. The differences between the two rating system, and probably the two cultures, are clear when it comes to the censorship of games. For example, for game “The Witcher,” its Europe version has nudity, while the US version has to be censored. In order for a game to be financially success, it has to reach a large number of consumers. In the US, the best way to do it is to be sold at large vendors like Walmart. However, Walmart, Target, and many others will not carry AO rating games and they require an ID check before purchasing an M game. This force many game producers to reduce the level of violence, foul languages, and sex in their games in order to maintain at least a T rating. Unfortunately, for certain games, particularly role-playing games, this decision severely affect the contents of them. It would be quite “out of place” if a foul-mouthed pirate never says a curse word, or a bloody battle has no visible blood at all.

The performance of a game is rated depending on the type of games. For different types, there can be different criteria, but it almost always comes down to the following four (not in this order of importance): AI, Story, and Graphics.

Probably, Artificial Intelligence (AI) is the most important. For AI, one of the criteria here is how well can an AI fight against a human opponent without resorting to cheat (using the existing game’s knowledge of map and resources as well as ability modifier). Another criterion is that how well an AI can do in performing micro-management for the human player. This relates to the shortest/safest path that your units will take in order to get to a destination, or when the player is leading the army fight away, and the home base is under attacked, how well the AI handles the defensive force. AI in gaming should not strive to be the best player. If AI wins every time, it takes the fun out of the game. Ultimately, the goal of AI in gaming is to mimic the behavior of a real average gamer, which is sometimes winning or losing, but with unpredictability.

Next, the story is particularly important to RPG (role-playing games) and MMORPG. RPG is like reading a book or watching a movie, only that the player is the main character. For single player RPG, the gaming world is static and the play time is counted at most by days, possibly weeks. The story needs only to follow the standard compelling original story with twists, possibly open-ended for sequels. For MMRPG, it is more difficult. The writers need to build an ever-changing world with history, a world that the players would care about. An RPG without a good story is like a man without soul. There has to be a reason why oldies with bad graphics such as “Baldur’s Gate” and “Planescape: Torment” still rank very highly compare to other newer games, and that reason is their great stories.

The last criterion is graphics. It is the eye candy of a game. Graphics is quite important for First Person Shoort (FPS) games, but for Strategy and RPG, it is not quite as important. A game with great graphics is very attractive, but it also requires the users to have up-to-date hardwares. A beautiful graphical addition to a game with already great AI and story will bring this game over the top.

The evaluation of a game is usually done by game review sites. Most of these sites are free. Some of them require paid membership for access to premium features such as fast download of game patches and demos. The official reviews of these sites are done by the editors, while they also post the cumulative scores of users rating. One should not place all one’s trust into the review of one site, since it can be very bias. Recently, there was a scandal at Gamespot (), one of the popular game review sites. Gamespot displayed advertisement ad from a prominent game publisher for one of their upcoming games. Upon the release of this game, an editor at Gamespot criticized it heavily in the official review. The game publisher pulls their ad, the editor was fired and people on the Internet were up in a bunch due to the treatment of Gamespot toward this editor. In my opinion, the best way to check on a game is to visit various forums, especially fan-based forums, to look for opinions, complains, and reviews. The gaming review site should only be used as a “prescreening” look.

I do not consider Second Life a game. It is an interesting virtual world, but it looks too much like the real world in order for me to relax and enjoy the game.

Gaming Standardizaton Efforts

There is an international trade association that creates benefits for gaming manufacturers, suppliers, operators and regulators, known as Gaming Standards Association (GSA). The identification, definition, development, promotion, and implementation of open standards to enable innovation, education, and communication for the benefit of the entire industry are facilitated by this association. This is one of the biggest organizations of the world that standardizes the gaming rules and standards. The committee characters include architectural oversight committee, gaming device standard, game to system, Marketing Advisory committee, Operator Advisory committee, protocols, transport. [12]

Gaming Conferences

World wide gaming conferences are held every year at different locations. Virtual world management, a show initiative, is one of the leading trade events media for virtual worlds industry. It conducts different virtual worlds and virtual law conferences and expos each year. The Virtual World and Virtual Law Conference are conducted on April 3-4 at New York, this year (2008). And the Virtual World Conference and Expo is on September 4-5, 2008, at Los-Angeles. This conference helps businesses harness the power of virtual worlds to engage with their customers, partners and employees. In general the conference concentrates on entertainment, marketing, virtual world’s on enterprise, platforms, technology, design, development, community and customer service, business strategy, investment. [13]

Useful websites

General information on virtual worlds:

•

•

Specific virtual worlds:

• Second Life -

• Second Life -

• Active Worlds -

• There -

• There -

• Entropia Universe -

• Entropia Universe –

News sites about virtual worlds:

•

•

•

•

Other useful sites:

•

•

References

[1] Wikipedia, {Accessed February 19, 2008}.

[2] {Accessed February 1, 2008}

[3] Schwartz, P., Bricker, L., Campbell, B., Furness, T., Inkpen, K., Matheson, L., Nakamura, N., Shen, L.-S., Tanney, S., and Yeh, S. (1998). Virtual Playground: Architectures for a Shared Virtual World. In Proceedings of the ACM Symposium on Virtual Reality Software and Technology 1998 (pp. 43-50). New York: ACM.

[4] {Accessed February 1, 2008}

[5] {Accessed February 3, 2008}

[6] {Accessed February 3, 2008}

[7] {Accessed February 19, 2008}

[8] Lucio Ieronutti , Luca Chittaro, A virtual human architecture that integrates kinematic, physical and behavioral aspects to control H-Anim characters, Proceedings of the tenth international conference on 3D Web technology, March 29-April 01, 2005, Bangor, United Kingdom.

[9] {Accessed February 18, 2008}

[10] {Accessed February 12, 2008}

[11] {Accessed February 14, 2008}

[12] {Accessed February 29, 2008}

[13] {Accessed February 29, 2008}

................
................

In order to avoid copyright disputes, this page is only a partial summary.

Google Online Preview   Download