VRML present and future

Byung-Gyu, Chang
CS Lab, Dept. of CS, Korea Advanced Institute of Science and Technology,
Taejon, Korea, 305-701
E-mail : chitos@baram.kaist.ac.kr
URL : http://oasis.kaist.ac.kr/~chitos/
Abstract:
This article explains the present status of VRML including history of VRML, specifications and Softwares to use VRML and the future visions of VRML.
Keywords:
VRML, WWW, Workshop

1. Agenda

Here, I don't deal the details of VRML specifications. Instead, the current status and the future vision of VRML are coverd based on the mertireals which can be obtained easily using WWW casue all is in Internet.

In chapter 2, VRML is introduced, its history and VRML 1.0's specification is written shortly. The softwares to use VRML are explained in chapter 3. And finally, in chapter 4, the vision and future of VRML is summarized.

All documents related to this article is written as links, so you can see those and get easily by clicking in browser, so I recommended to you that "Don't print it but see on-the-fly using Web cause it's the philosophy."

2. about VRML

For the novice, VRML is introduced and my opinion about the current status of VRML is added. The history of VRML is summarized. And Inventor from SGI is introduced cause it is the parent of VRML 1.0. And the extensions applied to VRML 1.0 was listed and explained.

2.1 What is VRML?

from VRML 1.0 specification :
"The Virtual Reality Modeling Language (VRML) is a language for describing multi-participant interactive simulations -- virtual worlds networked via the global Internet and hyperlinked with the World Wide Web. All aspects of virtual world display, interaction and internetworking can be specified using VRML. It is the intention of its designers that VRML become the standard language for interactive simulation within the World Wide Web."

The intension of VRML's designers were succeeded in my opinion. Virtual reality technologies which are developed in the very small closed rooms for many years are opened to the world's the largest space, that is, Internet with the most attractive system, that is, Web.

And the most important power of VRML is that it became the defacto standard of the companies which want to realize the 3D virtual reality using Internet. The most companies are follows the VRML 1.0 specifications.

2.2 Why VRML?

"Because the world is is not flat!" - from WebSpace of SGI

2.3 Brief History of VRML

VRML term was coined in April, 1994. And VRML 1.0 draft was released in November, 1994. It takes less than one year. And since, the libraries such as VRML parser and VRML viewers were developed according to the draft.

The background story from SGI's Rikk Carey and from Mark Pesce, the moderator of www-vrml mailing list, related to the developement of VRML is very exciting as a short stories without regarding the importance of VRML. Those are very good to know the history of VRML with the timeline of VRML developement is included in VRML FAQ.

2.4 Short review and an example of VRML 1.0 specification

VRML is not the extension of HTML. It is two different language.

except for the hyperlinking feature, the first version of VRML would not support interactive behaviors. This was a practical decision intended to steamline design and implementation.

I extract needed part from the contents of VRML 1.0 specification for the novice. The detail description about coordinate system, fields, nodes and extensibility etc. are skipped.

VRML 1.0 is designed to meet the following three requirements:

alike HTML requirements.

VRML file is represented as the hierachy of objects called Nodes. And a node has the following characteristics:

The following simple example contains a simple scene defining a view of a red cone and a blue sphere, lit by a directional light: 

#VRML V1.0 ascii
Separator {
    DirectionalLight {
        direction 0 0 -1  # Light shining from viewer into scene
    }
    PerspectiveCamera {
        position    -8.6 2.1 5.6
        orientation -0.1352 -0.9831 -0.1233  1.1417
        focalDistance       10.84
    }
    Separator {   # The red sphere
        Material {
            diffuseColor 1 0 0   # Red
        }
        Translation { translation 3 0 1 }
        Sphere { radius 2.3 }
    }
    Separator {  # The blue cube
        Material {
            diffuseColor 0 0 1  # Blue
        }
        Transform {
            translation -2.4 .2 1
            rotation 0 1 1  .9
        }
        Cube {}
    }
}

2.5 Relation with Inventor

Open Inventor from Silicon Graphics, Inc. is an object-oriented toolkit for developing interactive, 3D graphics applications. It also defines a standard file format for exchanging 3D data among applications. And Open Inventor ASCII File Format supports complete descriptions of 3D scenes with polygonally rendered objects, lighting, materials, ambient properties and realism effects.

As the document of Gavin Bell of Silicon Graphics which explain the relation Inventor and VRML in detail says, VRML is the subset of Inventor with extensions to support networking. He has adapted the Inventor File Format for VRML, with design input from the mailing list.

2.6 Extensions to VRML

Although VRML 1.0 is standard, there is some extensions cause the description about interactive behaviors is omitted intentionally and in fact, implementation choices can affect those specification.

There can be some extensions which is not listed in the above.

2.7 Miscellaries

To use VRML browsers, at least 486DX-50 CPU, 8Mbyte RAM is needed but it is crazily slow. So Pentium, 16Mbyte RAM is recommended.
The extension of VRML file is .wrl and The MIME type is x-world/x-vrml and x- means "experimental".

3. Softwares

Softwares related to VRML is divided roughtly in four parts. The first one is to browse the VRML files, the second to build softwares using VRML, the third to converter several file formats representing 3D, and final one is to build 3D space resulted as VRML files.

3.1 VRML Browsers

Other serveral browsers which is not running on Windows are omitted.

3.2 Libraries

3.3 Converters

Almost 3D Graphic file format can be converted to VRML.
And the other many converters are available but omitted. One of References are contained the links to the other several converters.

3.4 VRML Authoring tools

Many authoring tools are available as commercial products unlike VRML browsers. I haven't use anything of Authoring tools so I cannot introduce those. So I only list the names.

4. Future and Vision

In VRML futures meeting of VRML Archietecture Group, several papers had been submitted. You can the whole papers, here I will summirized or extracted key points from each papers to guess the future of VRML.

VRML 1.X - it is now future. VRML 2.0 - future but scheduled.

In summary, in VRML 2.0, interactive behavior, audio, physics, practical networking and the other major problems which is not specified in VRML 1.0 and 1.X will be covered. And more, using common API for VRML behaviors help the interoperability of VRML softwares.

5. Conclusion

Although we must need more computing power (more than Pentium and 16M RAM) to use VRML 2.0 perfectly, we can use the Virtual Reality in Internet alike using Web currently with support of VRML or other language superseded VRML.

So VRML, the first standard for Virtual Reality in Internet, is very important technology for the peoples who want to develope a VR system for the world (Internet) and we must keep our eyes on VRML.

References

The URLs which is not written as links in this article but referenced are listed here.

3D sites
Virtual Reality Modeling Language resouce links
URL:http://www.lightside.com/3dsite/cgi/VRML-index.html
VRML Repository
URL:http://sdsc.edu/vrml/
Cyberspace
Mark D. Pesce et al., Cyberspace
URL:http://vrml.wired.com/concepts/pesce-www.html
Platform Independent Virtual Reality
David Raggett, Extending WWW to support Platform Independent Virtual Reality
URL:http://vrml.wired.com/concepts/raggett.html
VirtualSOMA
Planet 9 Studios, Virtual SOMA
URL:http://www.hyperion.com/planet9/vrsoma.htm