Netscape Network ad

Bringing `behaviors' to VRML: Making sense of the avatar debate

Commercial success of VRML awaits avatar standards outcome

By Sue Wilcox

has become
[Netscape Enterprise Developer Table of Contents]

January 1997
[January 1997 Table of Contents]Table of Contents
[Archives]Topical Index
A common specification for how to handle ones virtual representation in 3D worlds, or avatar, as it crosses between worlds created by different vendors is what is holding back the deployment of Virtual Reality Modeling Language (VRML). This article explores three current proposals for how to standardize avatar interoperability, among other things. (7,240 words)

Table of contents
Universal Avatars specification

Living Worlds specification

Comparing Universal Avatars and Living Worlds

Open Community specification (formerly Universal Worlds)

Conclusion: Virtual world jumpstart

List of resources

The players within each spec


At the Earth to Avatars (E2A) conference in San Francisco in October, two of the original architects of Virtual Reality Modeling language (VRML) explained that they never planned for 3D virtual space to fulfill everyone's dreams of cyberspace at the first attempt. Mark Pesce and Tony Parisi said they always expected VRML to pass through three stages: geometry, behaviors, and multi-user interactions. "Cyberspace will not be built in a day," they reiterated.

Last August at the SIGGRAPH conference, the second stage was reached: the much-debated VRML 2.0 specificiation was approved and in addition to other things, it provided for the how to handle the behavior of objects. But, despite a lot of talk about the usefulness of data visualizations created with VRML 2.0, marketing and business types were still searching for signs of a 'killer app' to grow the market dramatically. And the most 'killer' use of VRML seemed to be in 3D chat environments where other human beings provided the added value needed to make sites popular -- without being too expensive to create and refresh. Given that VRML is a single-user three-dimensional environment, users preferred to be in static VRML 1.0 spaces (or VRML 1.0 spaces enhanced with Netscape's Live3D extensions, anyway) if it meant they could talk to other people while they were there. But this interaction all depended on proprietary multi-user technology to provide the means for users to see each other's representations, avatars, and to chat with each other.

Meanwhile, VRML software companies have also been experimenting with adding behaviors to avatars and objects that are similar to those possible with VRML 2.0, but which use proprietary formats for the most part. This was partly due to impatience with the gestation time of VRML 2.0 and partly due to a belief that proprietary solutions are better than the evolving standard ones. The avatars debate has arisen because the multiple proprietary solutions regarding how to bring avatars together to interact have fractured the potential market. VRML 2.0 will let your avatar interact with objects in a scene but does not provide a standard way to present the interactions to other avatars. In addition, there is no standard way for avatars to see and share the state of a scene, and no standard way to move from one world to another or to look from one world into another.

The result is that "pure" VRML 2.0 is little used while developers focus their efforts on formulation of the multi-user capabilities necessary to produce a fully featured interactive 3D space for a multiple-user killer app. Or, they're on working with proprietary technologies that can do this already e.g. Superscape plc's ".svr format," Worlds Inc.'s ActiveWorld, or Oz Interactive Inc.'s Oz-Virtual.

The focus on the future and VRML alternatives has been encouraged by the slow development of VRML 2.0 browsers and authoring tools. Essentially, the VRML community is looking to VRML 3.0, and the completion of the definition of VRML, before committing to developing content that uses the specification.

The avatar standards issue is therefore crucial to the success of VRML as a commercially viable language. Until there is some common definition of an avatar, and universality of movement between spaces on the Internet, it seems unlikely that any VRML company can hope to make serious money. Although the debate focuses on avatars, it is really just a special case of object interactions passing between a variety of servers in real-time. Talking about avatars personalizes the debate and brings up special issues to do with the nature of identity, security, interpersonal relations, and the nature of society on the Internet.

A number of companies have come together in interest groups supporting this and various other approaches. Three groups in particular have published first drafts of their specifications: (Note the groups overlap in some areas.)

Universal Avatar Standards group (UA)
Worlds Inc.
Velocity Games (now, I-Games)
Chaco Communications
IBM's Internet Division

Core Aim: The Universal Avatar Standards group focuses on the nature of avatars in particular with such issues as gender representation, ID authentication, personal expression vs. social constraints, avatar/world scale, and the communication of emotion.

The Living Worlds group (LW)
Black Sun Interactive
ParaGraph International
Bernie Roehl, University of Waterloo, Canada

Core Aim: "LW's group [has] low-level technical concerns with data distribution and scene synchronization," according to the group's literature. It looks at specific issues that need to be resolved for multi-user interactions to function.

Open Community (OC, formerly, Universal Worlds)
MERL (Mitsubishi Electric Research Laboratory)
Chaco Communications
Velocity Games (now, I-Games) Worlds Inc.

Core Aim: Open Community is a proposed open standard for multi-user virtual worlds. It consists of extensions to Java and VRML 2.0, and is designed to integrate with the Universal Avatars and Living Worlds specifications. The proposal is a combined effort of MERL and members of the Universal Avatars development team. OC looks at how to make an entire multiuser structure scalable to thousands of users and huge worlds, plus how to make real-time modifications and extensions to the environment while it is running.

A competition everyone wins
There have been some attempts to see UA and the other avatar standards under discussion as competitors. The Living Worlds consortium put out a statement it described as "media weed control" that compares the relationship between UA's and LW's proposals: "To make a (clumsy) analogy, if we were designing real-world cities instead of virtual ones, the UA discussion would be about the design requirements of office spaces, residential subdivisions, and amusement parks, while the LW's discussion would be about the need for standard plumbing joints and strategies for delivering electrical power at half a dozen different electrical voltages."

Now the task for the VRML community will be to fit the variety of approaches together. Let's examine the three proposals more closely.

Universal Avatars
The UA group is the first VRML interest group to deal publicly with the issues involved in standardizing the attributes of avatars. They are concerned with all avatars -- VRML ones, 2D ones, text ones, Voxel-drawn ones, and Virtual Humans, which refers to the group set up by VR News to exchange information about the development of autonomous agents that look like human beings. Avatars need more than just an appearance. They will want to carry belongings with them, perhaps have pets, give gifts, display emotions, and have an assortment of behavioral characteristics or capabilities (e.g., to kiss or dance the lambada, and be able to provide proof of ID for transactions).

This means many parameters must be settled as part of the standard or assigned to be the responsibility of the world creator. From how tall an avatar can be to fit into a world, to how complex it can be to render in a reasonable time, to how you can tell if it's a person driving the avatar or an artificial intelligence -- the debate has been multifarious, provoking, fantastic, and deeply interesting. A wide range of participants have been attracted to the discussions on the UA mailing lists. Subjects covered have included a range of philosophical, social, and technical issues:

Philosophical dimension
This deals with such issues as the nature of identity, and the relationship between reality and representation.

Social dimension
This deals with social and political structures, relationships between individuals as expressed through their avatars, the impact of the technology on real-world society, social control in virtual worlds, and maintaining consistency and accountability. Many of these issues are related to specific applications of the technology, such as: Should a visitor be able to write graffiti on the walls of your world? Is verbal harassment of other visitors acceptable? In OnLive's Utopia, there is a problem with headbutting of newbies -- should this be prevented, and if so, how?

Technological dimension
This deals with data structures, protocols, network standards, file formats, and related issues. Currently on UA's agenda are: a methodology for dealing with transitive behaviors, a proposal for size/scale and greetings issues, authentication/identity issues, language issues (how to detect what languages can be used and even what the possibilities are in terms of compatible technologies - text or voice chat, third party devices, etc.), how to deal with 2D avatars like those in The Palace and VPlaces, and geographic continuity between worlds. Clearly, technology shades into social and philosophical issues here.

Maclen Marvit, teleologist of Worlds in San Francisco, provides this overview of UA's approach: "We are at a point in our industry where lots of companies are doing innovative things, both technically and artistically. The goal of UA is to allow users to move as freely as possible between the technologies and find the best experiences in each, while maintaining a consistent identity. So if Bernie moves from one `world' [developed using] one technology to another `world' in another technology, he can maintain his avatar's representation, his Internet phone number and his proof of identity."

A UA file for avatars as currently proposed clarifies how this will work. It would contain:

  1. A link to a user profile, coded in HTML and containing data the user wishes to be known either about his fantasy identity or a true one
  2. Information for the rendered avatar model, be this 2D image(s), 2.5D sprites, or 3D geometry -- hierarchical or non-hierarchically structured. Major and minor "types" would allow a user to have both a basic VRML 2.0 standard avatar plus ones only viewable with a particular browser, such as Live3D using Netscape Communication Inc.'s extensions to VRML. (Just as in college you have major and minor subjects, there are preferred "types," or formats for your avatar and others that will suffice but aren't as good.) Other information held in this file could include: avatar size (visually), complexity, and the behaviors an avatar can perform or understand, whether transitive (relating to others) or intransitive (local to self).
  3. Proofs of identity
  4. Inter-world communication facilities for such things as Internet phone
  5. Vendor-specific extensions and user's history. A history could be with reference to games, for example, wizard status in a Role Playing Game (RPG), or it could hold marketing information about purchases made by credit card.

Living Worlds: making VRML 2.0 applications interpersonal and interoperable
Living Worlds proposes a set of VRML nodes that define a standard way of communicating between a VRML world and a multi-user technology (or "MUtech," to use LW slang). MUtech is the range of proprietary solutions that enable worlds to host multiple users. LW's approach is governed by concerns that standards that overconstrain developers will stifle innovation.

LW's will define the minimum set of system features needed to enable shared environments and the minimum set of standard interfaces required to let third party applications interact with the shared environment. To help assess the requirements for the LW's specification the authors created a simple domestic scenario, which is summarized below and available in full as part of the draft specification. (See Resources section, below.) Imagine you are a virtual home owner receiving guests for the evening. Your avatar is in the 3D representation of your home and there is a knock at the door, you open it and two avatars representing two of your friends walk in to visit with you. One is followed in by a pet and both are carrying packages.

The requirements for the Living World's specification are illustrated in the context of the "visitors for the evening" scenario. Here is the wish list:

  • To be able to insert objects/avatars into a VRML scene, such as "visitors [arriving] at the door." (Avatars are independently designed objects and may be completely new to the host's world.)
  • To track changes in the scene and communicate those changes in real-time. Position and animation of the avatars, as well as conversation all need to be conveyed to every participant in the world.
  • To allow objects to be driven by users in real-time. Manipulating an avatar's behavior is just one example of this idea, throwing a virtual ball or turning on a virtual radio are others.
  • To let objects be persistent, so you can give someone a virtual present and it stays when you leave.
  • To protect the local scene from damage by imported objects, depending how much freedom the world creator wants to give to visitors. Can a virtual pet chew up the furniture?
  • To be able to support rights for avatars, roles for people, and rules for scenes. A "right" can be the right to enter a world, chat on a particular channel, or to modify a world. A "role" is a link between a role name (such as `visitor' or `game-master') and rights such as: you can enter but cannot alter the world or restart a game. Rules are like laws of nature -- avatars can't walk through furniture unless otherwise specified.
  • To exchange information between objects, such as chat, HTML documents, business cards, etc.
  • To enable objects to be linked dynamically to non-VRML external functions and data. This covers interoperability between VRML worlds and external non-VRML functions and includes everything from databases, games, to such third party gadgets as dice.
  • To facilitate authentication of identity. Are your guests who they appear to be? Are their dice rigged or fair?

Bob Rockwell is chief technology officer at Black Sun Interactive, which is part of the Living Worlds group. His comment on these requirements for LW's specification is useful: "It is important to bring out that [this] list is not of things we want to standardize, but rather of things we want to hook up to in a standard way. Our job is to provide standard hooks to non-standard features that are still proprietary. To say it from the other direction, we want to pave a path for proprietary functions into the standard arena where everyone can use them."

Interoperability, openness, and innovation are LW's buzz words.

This diagram shows the major components of a multiuser system, which are the user interface, the VRML 2.0 browser, the VRML world itself, any external applications used in the world, and the MUtech. The numbers on the diagram label the interfaces. One through five are those of concern to the Living Worlds group. Number six is the job of the implementer of the MUtech and Number seven is the connection to other users over the network. LW has decided, in outline, how the components will communicate with each other. They have set the minimum requirements for interoperability between components (so any component can be supplied by any vendor) and started to design a framework so VRML 2.0 can support a multiuser application built with these components.

Living Worlds is strictly a VRML-focused effort. LW defines how to write a VRML wrapper so MUtech can plug into the browser. All of its concrete proposals for interface code are in VRML. It builds on VRML 2.0 and its authors are adamant that "it must be built entirely with VRML 2.0 mechanisms, defining as implementation specific anything which cannot be made to work inside the current standard." The design of LW assumes that VRML will be the development language of choice among cyberspace implementors.

Living Worlds aims to provide a framework for VRML 2.0 worlds to support interaction among Universal Avatars and promote a social community. The Silicon Graphics External Authoring Interface (EAI) proposal, developed by SGI and Black Sun, is a key component of Living Worlds, which enables communication between a VRML world and its external environment. (Details about the EAI are located at a URL found in Resources, below.)

LW's portable VRML 2.0 API represents intransitive behaviors and the unspecified proprietary (Java) APIs support transitive behaviors. Problems with the definition of the terms transitive and intransitive [coined by Moses Ma, whose company I-Games (formerly, Velocity Games) is part of the UA team] are shown by an example: What happens if you wave your hand (intransitive) but it intersects with my head (transitive impact)? Even accepting all that Living Worlds can do, a content developer must still build or license a proprietary multiuser API and server in order to run a multiuser world.

Ultimately the Living Worlds group intend to handle everything via dynamically downloaded Java applets. But at present, most systems prohibit Java from accessing local files, which makes it impossible, for example, to connect to locally installed third party software features. Until Java can access local files, the management of downloads and local access will be left to proprietary MUtech solutions.

Franz Buchenberger, chief executive officer of Black Sun, points out that until LW and the rest of the standardization initiative came along "each vendor of VRML-based online technology had to develop and market servers, avatars, clients, and worlds in order to ensure interoperability between all the pieces."

Now it will be possible to develop just content (avatars or worlds), or multi-user servers, knowing the other pieces will work together with it. This should enable an accelerated rate of development and better user confidence. Gregory Slayton, president of ParaGraph International agrees: "The Living Worlds standard should open up revenue-producing opportunities for companies that will specialize in helping people to develop their own personalized digital representations, or avatars, and to update them over time."

The supporting companies of the Living Worlds proposal have agreed that LW shall form a working group under the VRML Consortium, which was set up a few months ago to promote VRML standardization across the entire industry. The working group will benefit from the structure provided by the Consortium and from the input provided by all the Consortium member companies.

"This will ensure that the resulting standards take into account the needs of the entire community" said Tony Parisi, president of InterVista Software Inc and co-developer of VRML. The rationale for taking Living Worlds under the VRML Consortium umbrella is summarized by Bob Rockwell: "We want a standard which will `canalize' innovation toward a common standard. Hence, the creation of a standard set of interfaces for proprietary solutions to write to, and a clear statement of direction that we want those innovative proprietary efforts to eventually be brought into as a best-of-breed solution for the future standard."

Does this mean that, one day, all the proprietary solutions would become one? "More likely, there will emerge a common core of features for which the proprietary systems agree to use common interfaces," he says, "just as we have already done for avatar motion and behaviors that avatars are capable of."

The roadmap for the first draft of the LW specification includes: handling avatars and other active objects, simple communication using chat and business cards, a capabilities interface for whiteboards, and a simple security/rights model. The development timescale for the LW project is tight because the authors feel that the only way to test their ideas is by getting examples up and running, and trying out the interoperability of a group of worlds built according to their principles. They want a body of application experience to be accumulating while the VRML community debates the proposals for a VRML 2.x.

Draft 1.0 of the LW specification is expected before the end of 1996 so there can be implementations available before the community meets at the VRML '97 Symposium in February. (For more information on the symposium, see the Resources listing below.) Looking ahead, Black Sun's Rockwell says that "Phase Two will be the distillation of our implementation experience with Phase One into set of proposed extensions to VRML -- not just a library of ExternPROTOs but a new set of language elements covering this domain. Also, we expect to identify a few areas where the current standard needs improving, either wholly new features or things that should be done differently.

"The most obvious example is that of object-to-object collision detection, which the graphics guys were unwilling to accept in 2.0 because it caused them headaches (made certain things they do to optimize browser performance difficult to impossible). But object-to-object collision detection is utterly essential to multi-user work."

If there is an area of disagreement between UA and LW it is on the timing of "nailing down network protocols." UA wants to standardize an API -- essentially a standard protocol -- for applications to communicate through over the Internet, whereas LW wants to postpone this until VRML is multiuser.

Comparing Universal Avatars and Living Worlds approaches
Universal Avatars is essentially trying to set up the semantics of a data model for avatars, and this doesn't necessarily have anything to do with VRML. For UA it's a matter of enabling a community to exist and as Worlds' Maclen Marvit says: "In order to build a community, people have to establish relationships with others. But without persistent identities, without knowing that the Bob you met today will be the Bob you meet tomorrow, establishing those bonds is much harder. Our goal is the creation of communities, and UA is a critical step in making that happen."

One company involved with both the UA and the LW proposals is IBM Inc. The company's "avatar wrangler", Abbott Brush, clarifies the company's view of the two approaches: "The Universal Avatar proposal deals with issues ranging from persistent avatar identity to conventions for an inter-avatar behavior framework. The Living Worlds proposal involves specifying interoperable multi-user technology for inter-personal communications. IBM is very interested in providing avatars that are `personal, portable, and persistent,' so we are very pleased to be involved with both these complementary initiatives."

There is undoubtedly going to be a lot of what Abbott describes as "back room sessions" as the teams try to work out how they can position their ongoing work to ensure collaboration. To perhaps point up the politicking, Abbott notes that Universal Worlds/Open Community will probably wind up supporting Living Worlds and will be a reference implementation of it. He explains that it is based on Mitsubishi Electric Research Laboratory's (MERL's) SPLINE system, not VRML, which is of great interest to the other UA members who have non-VRML solutions. Moreover, UW/OC also includes application programming interfaces (APIs) for authentication and commerce. However, this goes beyond LW 1.0.

"Based on our existing commerce products, IBM is very interested in providing front-end technology to our transaction systems," Abbott says. "We will follow UW/OC, however, we are committed to VRML-based solutions." (To see IBM's avatar demo, refer to URL listed in Resources, below.)

Open Community, formerly Universal Worlds
Not everything proposed by UA or LW produces the idealized vision of cyberspace. The missing pieces are provided by Open Community. This proposed open standard for multi-user virtual worlds does not necessarily use VRML. This group has reservations about using a 3D scene-representation language as the foundation for cyberspace implementation, and has instead focused on Java. Because OC uses Java it can connect the avatar concepts from UW with the low level technology of LW and tie them into a system that is scalable and not tied to VRML. The Open Community architecture groups clients around a shared world model that is a pure abstraction.

The Open Community proposal is a joint development of members of the UA group and MERL (Mitsubishi Electric Research Laboratory). Open Community is based on SPLINE, a Scaleable Platform for Large Interactive Network Environments, a software architecture developed by MERL for dealing with multiple users over distributed systems. SPLINE has been in development for over three years and its Diamond Park demo only runs on SGI machines; it is based on the Performa graphics system. (Diamond Park is a virtual world where avatars can move around and talk to other avatars, ride bicycles in a velodrome, create new worlds, and play multiuser games.) Mitsubishi is currently working on commercializing SPLINE through its VSIS division, and is moving it across to the personal computer and VRML.

The particular features of SPLINE that make it so useful as the foundation for Open Community are: it uses "regions" to scale the world to the number of users; its multi-protocol communication system lets it cope with new media types easily; peer-to-peer communication reduces bandwidth and latency for data transmission; and strict object ownership prevents conflicts between interacting objects. (Regions are areas of a world, so a whole world is not presented at once, just the region around the user's viewpoint.)

SPLINE also enables the use of non-VRML applications such as a shared whiteboard or other collaborative applications in a virtual space. Many in the 3D community hope that Mitsubishi is going to donate SPLINE as part of the open standard for Open Community, which Glenn Coffman, director of market and business development at VSIS Inc., says is their expectation.

The "world model"
Open Community applications communicate with each other via a "world model" that allows applications to be written without having to consider communication mechanisms. (This is the underlying principal of divergent computer platforms being able to communicate over the Internet.) The model is one of an object oriented database that contains a "snapshot" of where everything is in the world and what it is doing at any instant. Applications observe the world by retrieving data from the model in the database. To avoid read/write clashes each object has only one process as its owner at one time, although ownership can be transferred. (A process is an action being run by the computer; if an object were being controlled by more than one process it could get into an `I say push and you say pull' situation.) The shared state of an object can only be changed by the object's current owner. To have persistent objects in the model, an application must make sure there are persistent processes to own them.

The architecture of Open Community is not centralized, as the "world model" description might suggest. The model is, in fact, resident in each user's machine and messages are sent over the network to propagate changes from one model copy to another. This ensures low latency interaction with the model. (It also means there is only approximate equality between world models.) The world model is divided into regions each of which are only "shown" to the users interested in that part of the world. This saves a tremendous amount of processing effort, especially when the number of users in a world is great. Each region is associated with a separate user service or channel so that processes that are not interested in a region can effortlessly ignore it. Scaling therefore happens based solely on the number of users gathered in one region rather than on the total number in one world.

Open Community servers
Because there is no central process, communication is largely peer-to-peer, minimizing latency and preventing bottlenecks. There is, however, a server designated as a session manager. It handles the connection and disconnection of users to a session in a world. One or more servers are also allocated the work of dealing with users coming in on slow connections. Messages to and from these users are specially compressed to take best advantage of the available bandwidth. Some servers have the task of caching the current state of each region so it can be downloaded to a machine whose user is entering a new region. This enables a process to gain access to the information very quickly.

Yet other servers act as name servers that associate names with objects and enable a process to find a remote object even if it is outside its current region. By spreading the load of managing the entire distributed system in this manner, no one server is overloaded and all servers can provide the best possible service to the client processes.

The Open Community process
The network interface of Open Community specifies the format for messages between processes. (A process in one world has to inform other processes about what it is doing. If I throw a ball, the process controlling its transit through the air must communicate to the process controlling the catch behavior in another user's world.) These processes are constantly updating the world model in the host client and all other clients joined into the world. All processes that use the message format can interoperate. This updating keeps approximate consistency between the copies of the world model.

There are three kinds of data in the world model: small rapidly changing objects, large slowly changing objects, and continuous streams of data. Open Community has an efficient scheme for synchronizing these different kinds of data. Small objects travel as Uniform Data Packets (UDP) or TCP packets. Large objects (including graphic models, recorded sounds, and behaviors) are identified by URLs and communicated via standard Web protocols (e.g., VRML, MIDI, and Java). Streamed data (such as audio or video) travels in a multicast or unicast message. As there is no limitation on the size of large objects, preloading is used to reduce latency time, but CD-ROM data storage can also be used with Open Community to reduce download time.

Artificial intelligence
As the use of intelligent agents becomes increasingly popular -- and even the creation of autonomous entities is being discussed -- the Open Community specification becomes particularly relevant because it considers how these types of simulations can interface with the world model. Basically the AIs hook up just like any other application but, because they do not require any audio or visual representation of the world, machines with no support for 3D graphics or audio can be used to manage shared content. Huge databases can therefore be joined into the world model to run complex simulations or animate intelligent entities.

But even for an AI, if it has no eyes it can be hard to tell which way an avatar is facing. The Open Community world model contains an object class used to identify avatars and a convention is imposed that the object faces down the negative Z axis. There is also an extensible facility for labeling objects with tags that carry semantic information. Conventions will be needed to establish how to use these tags so interoperability is maintained.

The buzzwords for Open Community are: portable, interconnected, scalable, multi-user, and interactive. These worlds are intended to run on any manufacturer's Open Community-compatible server. Server software developers can then choose to differentiate themselves by optimizing their offerings for speed, robustness, and additional proprietary features (such as latency mitigation technology, morphing, interpolation algorithms, etc.). Visual and audio rendering become just browser plug-ins running on top of Open Community. This means Open Community can be easily interfaced to any renderer. As rendering engine choice is usually an emotional subject, this flexibility is a real advantage. A content developer using Open Community can license a multiuser API and server from a third-party and then write multiuser behaviors in any language -- Java being the most portable -- so the behaviors can run on any machine. The advantage of using the Open Community Java API and VRML prototype layer is that developers can create a world that operates with anyone else's server.

Karl Jacob, chief executive officer of Dimension X, comments: "The Open Community effort will go a long way to achieve multi-user capability and help encourage adoption of VRML."

While UA has proposed standardizing many of the features required in avatars, such as persistence, scale, and the design features of the interface used for socialization, Open Community has implemented these concepts already in the classes spAvatarinfo and spAvatar. This is one example of how closely the two groups are working. Chaco Communication's president, Dan Greening, supports the spirit of cooperation between the three standards groups: "The Open Community proposal provides the missing link to worldwide social computing. Its Java libraries were designed for seamless support of multi-user environments such as those proposed in Living Worlds."

"We look forward to participating in the next step in the evolution of VRML, and integrating Open Community capabilities with those of the Universal Avatars and Living Worlds proposals," Black Sun's Rockwell says. "We were delighted to discover how neatly the Open Community design work dovetails into LW's proposed VRML interfaces, and welcome MERL's generous commitment to support the ongoing evolution of Living Worlds and the VRML standard."

Virtual world jumpstart
Agreeing on avatar standards is critical to the growth of the virtual world industry because it will allow users access to a range of worlds without having to change virtual bodies. And until easy access to a wide-ranging assortment of worlds is available, content providers will not feel comfortable with the potential of the market. Once there is an avatar standard, content providers can market to those avatars -- whether it's a matter of the type of worlds that can be established or the types and varieties of avatars that can be created for consumers.

Once avatar creation companies have become common, the prices of avatars can come down. Currently, Third Dimension is charging $49.95 to make a photorealistic avatar head. Lowering the price of avatars will make them more widely available and grow the market. Once there are avatars in cyberspace with spending capacities, and once they can be influenced by advertisements and virtual salespeople, then creating worlds to attract avatars can be expected to proliferate.

Come together
The development of open standards has been shown to be effective in many other areas of computing. The next step for three dimensional cyberspace is the combination of all three avatar proposals into one open standard to be integrated into VRML 3.0. It is hoped that the amalgamation of these three approaches would not dampen the innovative work that is often the hallmark of individual companies.

A final specification is needed for the networking protocols to be used between server and client to form what the Open Community people call Universal Cyberspace. The dream scenario is for a baseball player in a virtual world running on one server to be able to hit a ball out of the park and have it crash through the window of a storefront running on a different company's server.

But outside the dream is the commercial world and the mass market. When former Apple Computer Chairman John Sculley gave his analysis of the future of cyberspace at the Earth 2 Avatars conference recently, he said that once the technology is shown to work and standards are agreed, the big league players will move into cyberspace.

Advertising has not been shown to be effective on the Internet. If you look at what is available in the way of banners and little animations on the Web, and compare that to a regular television commercial, the lack of impact on the Web is profoundly noticeable. It will take expensive production techniques and lots of bandwidth to output the sort of quality ads on the Web that people are used to on TV. And it takes a revenue stream to support that investment. Only companies with multiple media assets can justify and afford multi-channel distribution and advertising. Sculley, who is now the president of Live Picture, predicts that the likes of Disney and Time-Warner will become the moguls of interactive 3D content provision on the Internet. And that content may well be free.

As avatars become members of self-organizing groups, Sculley sees them as "a driving force shaping the economics of this industry." The avatar standards movement is the next step to achieving cyberspace.

See you on the strip. []


About the author
Sue Ki Wilcox is an author and specialist in Internet 3-D computer graphics, virtual reality, VRML tools, and other resources for worlds builders. Often found out and about as conference reporter for Web Techniques magazine, Sue is organizing the VRMLocity conference to be held in San Francisco in June 1997. Sue is co-author of the book EZ-GO: Oriental Strategy in a Nutshell. Reach her at


The Players

Universal Avatars:

Living Worlds:

The following companies have expressed support for the Living Worlds initiative: 3Name3D, 3D Labs, Acuris, 3rd Dimension Technologies, Aereal Inc., Apple Computer, Archite X, Axial Systems, Barnegat Communications, Black Sun Interactive,, Chaco Communications, CyberPuppy, CyberTown, Extempo Systems, Fujitsu Laboratories LTD, First Virtual Holdings, GrR HomeNet, IBM, Integrated Data Systems, Intel Corporation, Intervista Software Inc, Media Authoring Center - George Mason University, Netcarta, Neuromedia Studios, OnLive Technologies, Oracle Corp., OZ Interactive, ParaGraph International, PeopleWorld, Planet 9 Studios, Sense 8, Silicon Graphics, Sony Corporation, Velocity, Vivid Studios, VREAM, VRMLSite, Worlds Inc.

Open Community/Universal Worlds:


The relationship of an avatar to a real-world individual or an artificial intelligence (AI), which can vary in usefulness and personality from an answering machine to an autonomous entity. This includes such things as multiple identities, gender, links to other resources (such as Web pages or e-mail addresses), ID validation information to enable financial transactions, and so on. Note that identity refers to how identity is stored and transferred rather than a philosophical question.

Intransitive behaviors
These are behaviors that are local to one user or object. Problems arise with the definition when considering if a local behavior such as dancing or blowing kisses need to be understood by another avatar.

An object oriented programming language used to add actions to Web pages. There are a variety of proposed interfaces to join Java to VRML 2.0. Java will be used to drive complex behaviors, communicate with a server, and animate avatars and other objects.

The 'Earth to Mars' communication gap between an avatar performing a action, like kicking someone, and the recipient of the kick reacting. Largely an infrastructure hardware problem, latency can be worked around by using localized responses (like having a hind-brain to work the back legs of a dinosaur).

All aspects of an avatar's appearance. This includes such things as geometric description language (VRML or otherwise), relative sizes of avatars (scaling and complexity), decency controls, copyright controls.

Role Playing Game

Some who studies evidences of design in nature, or the use of design or purpose as an explanation of natural phenomenon.

Transitive behaviors
Actions made by one user or object that are expected to affect another user or object. The ability of the avatar to affect its environment and be affected by it. This includes such things as manipulating objects in the environment, communicating with other avatars using text or speech, body language and gesture, exchanging data, and so forth.

VRML 2.0
A single user animated 3D virtual environment specification that can associate automated behavior with a 3D object. Through a programming API, VRML 2.0 allows content developers to create animation's.

The following definitions are particularly applicable to Living Worlds but will probably spread into more general usage.

Shared Object whose pilot is under real-time user control.

Functionality available to, but implemented apart from, a World (i.e., not one of its Scripts).

A Shared Object active under autonomous program control.

Avatar functionality implemented by an application or script.

Instance of a Shared Object replicating the state/behavior of a pilot.

In the multi-user 3D world context, a hardware/software system serving a single user.

In the multi-user 3D world context, a system coordinating communication among avatars running on various clients.

MUtech or Multi-User technology
Living Worlds' term for the component which manages the shared Objects in a zone.

Instance of a Shared Object whose states/behaviors are replicated by other instances drones.

Regions are areas of a world, so a whole world is not presented at once, just the region around the user's viewpoint.

A set of VRML objects that is geometrically bounded and continuously navigable. (see World)

A set of instructions as defined in VRML 2.0 spec

Shared Object
An object in a scene whose state and behavior are synchronized across multiple clients.

One or more scenes linked together both technically and conceptually. (see Scene)

A contiguous portion of a scene. Technically, a container for Shared Objects. (Note: Mitra of ParaGraph, one of the developers of the VRML 2.0 spec, defines world, scene, and zone to distinguish aggregations of separately implemented scenes (conceptually integrated wholes, e.g. virtual cities), from subdivisions of what appear to the user as seamless spaces -- into zones with very different characteristics. In other words, world, scene, and zone are a way to divide a large space into smaller chunks, although the chunkiness is invisible to the user. A chessboard might be a zone in a scene of a house that is part of a world.)