Web-Based Graphics For Virtual Environments

Event Driven Graphic Delivery

Keeping in mind that the goal of our technology is the harmonious marriage of the Web and the MOO, is important to understand that everything that happens in a MOO happens as the result of an event. Events (and their results) have traditionally been represented by a textual description. For example, when Mark connects the MOO everyone else sees a line of text announcing that event.

Integrating graphics into the event stream brings the tremendous power of visualization. Delivering those graphics with generic HTML eliminates the potential complications of proprietary systems. Clients can connect and interact using nothing more than their web browser and have the option of exploiting the growing array of plugins and media types like RealAudio or InternetPhone just to name two.

So MOO events can trigger web media delivery! This allows for a simple yet elegant means of implementing Avatars and visual environments. Now when Mark logs on, his avatar's visual image can be added to everyone else's screen.

Though real-time graphics over the Internet is not yet available in a practical way, especially for users connected with ordinary modems, we provide a graphics channel supporting near-real-time graphics in parallel with a real-time channel for text-based interactions.

For most educational and business purposes, this provides an adequate solution. More sophisticated, customized solutions are available to the intranet user with adequate bandwidth.

How Do We Blend the Protocols?

The Web Projector

Our objective was to develop a means of delivering graphics to the user, on command from the environment (i.e., without the user having to click on anything or load a URL), and without requiring any special software on the user's side of the interface.

To accomplish this, we designed the Web-Projector, which is a graphics server that runs on the remote host, separately from the MOO environment, but in close cooperation with it. As many Web-Projectors may be operated from the environment as are desired, and each one will serve multiple users on multiple content channels.

All users logged into the same content channel will see the same graphics material, and each will see it updated as the virtual environment commands the Web Projector to show new material. For example, a teacher holding a discussion with a class can present graphic material via a particular channel to which everyone in the class was "tuned." All the students would see the new material as the instructor put it up.

Features

On any of its channels, the Web-Projector can show any URL on the Web, or graphics from a locally-cached set of images. The Web-Projector need not even reside on the same site as the virtual environment, and can also show stores of private graphics from remote sites, making it a very flexible instrument. It maintains an Index Channel which allows users to select other channels, and which also gives the person presenting the graphics an indication of who is viewing which channels, and whether they are still down-loading or have received a new image, permitting speakers to pace their presentation to listeners with slower links.

Multiple Multi-Media Channels

The teacher in our sample above is not limited to one channel per class, nor does that channel have to carry "graphics". Presenters are free to push any data format that can be accommodated by the HyperText Transfer Protocol (HTTP) as they wish. It would then be up to the user's (client) computer to be able to "display" the data. This makes it possible to include streaming audio and video in teaching and conferencing sessions.

Data Can Be Stored Locally

And, there's no reason the information has to be transmitted over the net, either. Imagine the university that chooses to provide Distance Education resources using this technology. Given the low cost of Compact Disc recorders and media it would be very feasible for instructors to present a CD to each student and assume the student had that CD loaded during class. Our server simply sends each student a URL that points to their own CD-ROM.

Projector Control

The Web-Projector also permits filtering of screens before presenting them to the viewers. One typical use of this capability would be to remove hyperlinks from public URLs originating elsewhere to prevent students from "net-surfing" to links not intended by the instructor.

Possible Applications

• A presenter mount a slide projector in the virtual environment containing the URLs pointing to the material to be present.

• A virtual microscope into which an instructor may load a set of slides that may then be viewed by a student at their own pace.

• A virtual frog-dissection lab which allows a student and instructor to jointly view an excellent educational resource at Berkley and to discuss together what the student sees as he or she interactively runs the experiment.

• A live map of the environment which shows the plan of the part of the environment the user has entered, and which is automatically updated by the environment as the user moves.

We can also use the Web-Projector to deliver text to a browser screen a line-at-a-time as it is generated. Uses have included a window from the Web into rooms of the environment which allows observation (for example by a parent or an administrator) of events in the environment without the necessity of their logging into it and disrupting ongoing discussions, and similar access to other text-based materials in the environment such as whiteboards.

 

ABOUT HYBRID TECHNOLOGY

Best of Both Worlds - Object Oriented, Client/Server technology combines text and graphics in remote virtual environments.

ABOUT TEXT-BASED VIRTUAL REALITY TECHNOLOGY.

The history and evolution of the MUDs/MOOs and defining features.

[The WorldSmiths HomePage] · [ Connect to The World ] · [ Site Map]