ERCIM News No.29 - April 1997

ERCIM Computer Graphics Network Workshop on Virtual Reality Modelling Language

by David Duce

The ERCIM Computer Graphics Network organised a workshop on Virtual Reality Modelling Language (VRML) at the Coseners House, Abingdon, UK, on 29-30 January 1997, attended by 22 researchers from academia and industry from 6 European countries. The idea for the workshop came from the Steering Committee of the ERCIM Computer Graphics Network in May 1996. It was felt by the Steering Committee that a workshop was needed in order to formulate a European view on VRML. VRML is described as 'a file format for describing interactive 3D objects and worlds to be experienced on the World Wide Web', the significance of VRML is that it gives the web a graphics and interaction capability of significance to many application areas. Many ERCIM institutes are using VRML and have VRML-related activities.

VRML 2.0 has been put forward for standardization to the ISO/IEC Committee responsible for computer graphics and image processing (JTC1/SC24). A review of the document took place in the autumn of 1996 and an Editing Meeting to address the 500 comments raised took place in the USA in December 1996. Several members of the ERCIM Computer Graphics Network were involved in the preparation of these comments. Three major concerns identified in this process were the suitability of VRML for use in visualization applications and the use of VRML in multi-user worlds and the quality of the VRML document itself. The ERCIM Workshop focused on the first two of these issues.

The meeting opened with an introduction to the background and aims of the workshop, given by David Duce. Anthony Steed, from University College London who was a member of the UK delegation to the ISO/IEC VRML Editing Meeting gave an overview of the state of the VRML document within the standardization process. Two talks were given by researchers from the University of Leeds, introducing the topics of VRML in visualization and multi user worlds and describing work in progress at Leeds in these areas. The meeting then split into groups to address these two topics in more detail. At the close of the workshop, reports were received from the two working groups and recommendations to ERCIM were formulated.

The Multi User Virtual Worlds (MUVW) group was chaired by Michael Wilson, Rutherford Appleton Laboratory.

The group took four documents as the basis for discussion:

Many recommendations were made by the Working Group which will be fed into the VRML Consortium Working Groups. These covered topics such as scope of VRML, architectures for MUVW, efficiency/ communications issues, object creation, consistency, persistence and portability.

The Visualization group was chaired by Klaus Kansy, GMD.

Examples of the use of VRML in visualization work at the University of Leeds and British Telecom were presented. Starting from these examples and a reference model for visualization the group addressed where and how VRML can be useful in visualization and where the deficiencies are. The major issues identified were the need to control where interpolation is done (which implies the need to carry application data along with geometric and colour data), the need for better colour model support, and the need for better facilities to handle large data sets (for example some form of lazy fetch). Support for volume visualization is also missing in VRML 2.0. Some support is provided for sound, but no support is provided for either sound synthesis or acoustic properties. Both are required to support sonification applications.

The closing plenary session received reports from the groups and formulated recommendations. Apart from the technical recommendations outlined above, there were recommendations that ERCIM should join the recently formed VRML Consortium ­ the VRML analogue of the WWW Consortium ­ pass the output of the MUVW group to the relevant VRML Consortium Working Groups and seek to establish a new VRML Consortium Working Group in the visualization area. Although the request to join the VRML Consortium did not find favour with the ERCIM Executive Committee in the form in which it was presented, I am hopeful that a way forward will be found to enable ERCIM to join the VRML Consortium on an annual review basis.

Since the Executive Committee meeting took place, Dave Nadeau at the San Diego Supercomputer Center has announced an Information Visualization Working Group meeting to be held during the VRML 97 Conference and has established a mailing list and repository (see for more information). One of the discussion items for his workshop is whether to create an Information Visualization Working Group in the VRML Consortium! The results of our discussions have been fed to him. Membership of the Consortium would put ERCIM in a much stronger position to contribute European expertise to these developments. We live in hope!

The full report of the workshop has been published as ERCIM Research Report 02/97-R049 and is available through the ERCIM web site at

Please contact:
David Duce - CLRC
Tel: +44 1235 44 55 11

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