Intelligent Systems Report € May € 1996 € Volume 2 € No. 5

VR enters collaborative networking arena

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By David Greenfield
Managing Editor

Computer networks have drastically changed the way businesses operate. The use of LANs (local area networks), WANs (wide area networks) and the Internet have enabled companies to easily perform business transactions and transfer information not only within the comfortable environs of the workplace itself, but internationally as well. Historically, these networks have been used for the transfer of one-dimensional, or at most two-dimensional, information. Now, virtual reality (VR) has entered the networking fray.

Holding promise for industrial design as well as marketing, collaborative networked VR permits users at the same or remote sites to enter an immersive VR environment and manipulate objects in real-time. The basic components of a networked VR system include a view of the virtual world for every user and some kind of representation of the user -- an avatar. The other participants are also visible to each user.

According to Doug Schiff, vice president of marketing, Division Inc. (Chapel Hill, N.C.), a provider of VR development tools, virtual reality networks must be interactive. "That means not only moving around the world and having interactive images, but being able to manipulate that world. You've got to be able to create objects, assign behaviors to them, change those behaviors, delete objects, and manipulate them. In other words, change the virtual world. This is critical. Just viewing virtual reality is only halfway there. Being immersed in a world means being able to participate in that world."

Speaking at the recent VRWorld conference in Boston, Schiff said, "Immersion is key to an interactive virtual world. One of the main reasons for this is the natural movements you get from immersion. You get a sense of scale and size and location."


Uses of networked VR
The most common use of collaborative, networked VR is concurrent engineering -- different groups creating different parts of a mechanical design in different locations and in different parts of the design process. One user will be building a certain component while somebody else tests it for installation or maintainability, and yet another user performs training on that component.

Networked VR can also be used in design reviews. Schiff said, "Right now, at a large automobile company, they'll have groups all over the state or city doing frequent design reviews to evaluate different components of their design -- a piece of an engine, a piece of a car body, the entire assembly, all different parts of the process. Without collaborative, networked VR, you have to bring all those people together in one room or have a video conference. What VR enables them to do is gather around a virtual prototype and evaluate the design together in real time."

One of Schiff's first real-world uses of collaborative VR involved the marketing of an engineering design. "Our customers were doing engineering design and their customers were located elsewhere. They were able to give presentations, walk-throughs and demonstrations from remote sites.

"Also, an important part of marketing is getting early information about mechanical designs. With collaborative VR, an opportunity exists to link up sales, marketing and engineering at an earlier stage in the process."

Yet another proven use for networked VR is training, where experts are in one location and the trainees are in another.


Implementation
To implement collaborative VR, Division uses dVISE, a VR application that imports previously established design data, such as CAD, and uses that data to build interactive virtual worlds. The building of a collaborative virtual world starts with the use of some kind of CAD model, which is translated by dVISE into a 2-D Windows-based interface or a 3-D immersive interface. dVISE information runs over DVS -- a run-time environment operating on a set of multiple-independent servers, called actors. Each of these actors handles a different part of the virtual world. For example, there is a visual actor, whose purpose is to create images; it doesn't know anything about collisions or interaction, it only generates images. There is also a collide actor; all it deals with is one object meeting another object.

An added benefit in a networked situation is that these different actors don't need to run on the same processor. In a networked, collaborative VR setup, these actors could be running on separate network workstations. There are numerous advantages to this type of architecture. One of which is that it takes advantage of multiple-processor systems, which are becoming more commonplace.
"If you know, for example, that you want to do a lot of collision detection, you could devote a single processor to just worrying about the collide actor. You could then have all the other actors run on a separate processor. It gives you the opportunity to customize your installation to get very high performance," Schiff said.

Division has already participated in a number of networked, collaborative VR projects, including:

• The Virtu-OC Project -- a government-funded project in the U.K. designed to develop computer-supported cooperative work. The project looks at two industries in general: industrial and textile manufacturing. It involves linking marketing and the shop floor using collaborative VR between these separate entities.
  
  
• Developing a collaborative VR network between three sites -- one in The Netherlands, one in Portugal, and one in the U.K. This project involved an architectural group in Portugal that was doing some work for a city in The Netherlands. Through the use of collaborative, networked VR, the Portuguese company was able to conduct a virtual, collaborative presentation to its Dutch clients.

Issues
"Connections are always an issue," Schiff pointed out. Right now the Internet does not work very well with VR, though recent efforts to develop a VRML (Virtual Reality Markup Language) standard on the World Wide Web show a lot of promise (see ISR, March 1996). There is not enough bandwidth and connections do not have the appropriate stability. ISDN will likely be the most common method of establishing the proper connections, according to Schiff. Another effective method of establishing such a network is with the use of WANs.

"Networked VR is a reality," said Schiff. "This is not a research project; this capability is already standard in our software. Networked VR will help in design, and in marketing and training. It will be as common as every other kind of network we have right now."