Report on Virtual Environments '98

VE98, combining the European Virtual Environments Conference with the 4th Eurographics Workshop on Virtual Environments, was held at the Killesberg Messe, Stuttgart, Germany, from 16 - 18 June 1998. The venue, located deep in the heartland of the German automobile industry, provided an excellent setting for bringing together the latest results from academic research groups in Europe, the USA and the Far East with a number of case studies illustrating the current use of VR in industry. The impressive results being achieved in companies like Daimler-Benz, Porsche and BMW are clear evidence that VR is no longer a novelty with little real world relevance. It is now an essential tool delivering competitive advantage to some of the world's leading industrial organisations.

Opening presentations

The event, ably organised by Juergen Landauer from Fraunhofer IAO in Stuttgart and Martin Goebel from GMD in Bonn, was opened by Prof Bullinger (MD, Fraunhofer IAO). He described a number of the key trends which mark the growing maturity of VR. These include greater integration of VR into industrial design and production processes, the replacement of physical models with virtual prototypes in the development of new car designs and the emergence of more usable VR technologies. Although CAVEs, cubical viewing chambers with real time images projected on 4, 5 or 6 faces, seem to be springing up in large numbers throughout Germany, other, less expensive, alternatives such as workbenches and projection walls can provide equally effective ways of sharing a 3D interactive experience within design teams.

Medicine is making increasing use of VR for training, diagnosis and therapy. Prof Schraft (MD, Fraunhofer IPA) continued the opening session by describing how virtual endoscopy using MRI scan data is providing a non-invasive alternative to conventional techniques. He outlined how the operating theatre of the future may involve the surgeon sitting in a 6 degree-of-freedom cockpit chair which moves to reflect the orientation of the tip of the endoscope as he immersively steers it with sub-millimetre precision through the patientÕs brain.

Keynote talks

The invited keynote speakers were Mark Mine, Arthurine Breckenridge, Toni Emerson and Ryohei Nakatsu with Naoko Tosa. Mine (ex University of North Carolina and now Disney Imagineering) described some of the problems of precisely manipulating objects in VEs and of providing a consistent framework for interaction. Techniques employing proprioceptive information, such as scaled-world grab, body-relative pull-down menus and over-the-shoulder delete are intuitive and can provide a greater degree of control. He went on to describe projects he is now working on for imminent release at DisneyQuest in the Epcot Centre including a CAVE-based multi-user participative version of Hercules and a further development of the Aladdin theme using HMDs. In all there will be about 30 SGI Onyx systems powering real time interactive attractions in the 5-storey DisneyQuest building.

Breckenridge (Sandia Labs) showed videos of visualizations of the results of numerical simulations of a cometary impact in the Atlantic Ocean off Manhattan island. Clearly not a good place to be if it happens! These multi-gigabyte volume datasets can be explored in real time using VR techniques. Sandia are carrying out collaborative visualization experiments with the visualization group at the University of Stuttgart.

Emerson (University of Washington) described the work of the HITLab including their current development of the Virtual Retinal Display in which a low-power laser writes directly onto the wearerÕs retina. The production version of this transparent display system is intended to resemble a pair of ordinary spectacles.

Nakatsu and Tosa (Advanced Telecommunications Research, Japan) presented a fascinating interactive poem demonstration in which their system responded with simulated facial expressions of emotion and with verse of its own to lines spoken by the presenter. This was followed by a somewhat confusing (for this viewer) interactive cinema demonstration in which the words and actions of real actors were interpreted in real time into a virtual re-enactment of the Romeo and Juliet story. An interesting antidote to the scientific and engineering bias of most of the event.

Research projects

A small selection from the many interesting presentations of current research work follows. Bullinger (Basel University) and Roesslar (Fraunhofer IAO) described how VR is being used with claustrophobia patients using a virtual shrinking room. The patient wears a VR4 HMD and is monitored to measure blood pressure and pulse rate. The results indicated that the virtual experience was capable if inducing similar physiological symptoms as real life exposure and therefore could potentially form part of a treatment programme.

Mulder (CWI) presented the results of a series of experiments in which various techniques for remote object manipulation in a VE were compared. Having the object attach itself to the end of a virtual laser beam originating from a wand in the userÕs hand and then move with the beam was found to be the most efficient.

Huxor (Middlesex University, Centre for Electronic Arts) described his experiments using the AlphaWorld browser to construct shared VEs to emulate and encourage the chance encounters which can occur in real life and which form an essential part of the human interaction process within an organisation. Content within the virtual world is managed and accessed through the BSCW collaboration support system.

Slater et al (UCL) presented the results of a series of carefully constructed experiments to assess the level of presence felt by users in a VE. This was measured by giving them tasks of varying degrees of difficulty to carry out and test how their sense of presence, as measured by questionnaires on exiting the VE, was affected by this and by the degree to which they had had to use body movements within the VE. An interesting addendum to their experiments explored the subjects' degree of presence in the VE by presenting them with contradictory stimuli which forced them to choose between sensory signals from the virtual and real worlds. This work draws an interesting distinction between subjective presence as reported by the subjects verbally and behavioural presence as evidenced by their response to events. The results, although tentative, were reassuringly self-consistent.

Kindratenko (NCSA) and Kirsch (GMD) described their experiments in collaborative vehicle design using a shared VE implemented over a transatlantic ATM network connection. This used live audio and video embedded within the VE via a video conference application running in parallel with the rest of the system. Communication used IP multicast protocols and suffered from performance and reliability problems.

Fuhrmann et al (Vienna University) showed a simple technique for navigating through a VE using only head movements. The user was equipped with a normal tracker device attached to a pair of i-glasses. Head rotation (yaw) defined direction to travel and head up and down movements (pitch) indicated travel forwards and backwards respectively with angle defining velocity. Sideways tilting of the head (roll) was used to toggle between standing still mode, where head response is disabled so the head can be moved to view an object, and walking mode, where head movement triggers motion. Simple, but it worked (on the flat only!). User learning time was less than a minute.

Ko (Korea IST) described a method for automatically composing arbitrary facial expressions from linear combinations of a set of pre-defined expressions. A distributed genetic algorithm was used to find the coefficients for synthesising the expression for a virtual character based on analysing an image of the face of a real actor.

Industrial applications

An important element of VEÕ98 was the strong industrial component of the programme. This comprised several parallel sessions on industrial case studies and solutions. These were presented either by a RTO working in collaboration with an industrial partner or directly by an industrial speaker. They generally spoke openly and frankly about their companies' experiences with VR. Although in some cases a written record of their talk was not provided, the material presented gave valuable insight into current and future industrial applications of VR.

Reuding (BMW) explained how they use VR to examine the results of crash simulations involving meshes with 105 to 106 elements. The original computational meshes are reduced to enable real time interaction while preserving high precision in the areas of interest. The meshes and solution data are time dependent and everything must be kept fully consistent at each time step. Individual components can be enabled or disabled, interactive cut planes can expose internal details of the deformed structures and the rendering parameters can be changed interactively, for example to make objects translucent. Individual objects can be removed from the whole car model and their dynamic deformation viewed separately. The advantages of using VR were cited as increased communication between experts, a reduction in post-processing and interpretation time of 50% and better insight into complex scenarios. A comment that the biggest pay-off was in detecting the unexpected clearly left much of great commercial significance unsaid!

Stratmann (Art+Com) described a project commissioned by Mercedes-Benz to provide a VR system for use initially at motor shows but eventually in car showrooms. This consisted of a boom-mounted touch-sensitive 20Ó LCD panel with handles on the side which could be easily moved around and oriented in space. On the panel the user could see a view of that part of a virtual car which lay ÒthroughÓ the panel as if it were a window. The range of movement of the boom and panel covered the volume of a real car so that, by manoeuvring the panel in space, all details of the virtual car could be examined from the exterior lights to the switches on the dashboard. By standing back, the whole car could be seen at once. Using control buttons on the panel, the user could change the colour of the car, the optional components and its interior finish to customise the car to his choice. Animation of, for example, seat folding could be requested. Having seen and decided on the exact specification required, the final step was to enable the customer to place an order electronically. Extensive manual optimisation of the original CAD dataset was necessary to reduce it to about 5M polygons which could be interactively viewed using an Onyx2 IR system.

Lutz and Ziegler (Fraunhofer IGD) presented a VR tool for landscape planning developed in partnership with Wismut GmbH, a mining company. The aim was to be able to show local residents and pressure groups how redevelopment of large surface deposits of mining waste could be achieved and the appearance of the resulting countryside. From this VR model, fly-throughs could be produced for interactive viewing or video recording.

Panels

The conference also included several panels addressing topical issues. These were on medical applications of VR, VR in the telecommunications industry, VR in the automotive industry and VR for geoscientific data visualization. There was also a panel, chaired by Max Lemke of the EU Commission, which explored the potential of VR as the future engineering workplace in the context of the next EU Framework Programme.

Demonstrations

Running concurrently with the conference there were demonstrations of VR equipment including a two-surface workbench and a stereo projection system using polarised light. Various PC-based 3D graphics systems were also on show and demonstrated their increasing competitiveness with the traditional VR platforms. A recurrent theme during the conference was the cost of whole-body immersive locations such as CAVEs. While these currently constitute flagship centres for VR technology, their economical justification is less clear and more cost effective routes to widespread commercial acceptance of VR must be found.

Conclusions

In summary, this was a very interesting and well organised event. The formula of bringing together the conference and workshop in a trade show location was successful and resulted in a strong attendance from industry as well as academia. It clearly demonstrated that VR is now well down the road to acceptance in industry but there are also still many interesting research challenges to be met and commercial hurdles to be overcome if its applications are to be broadened beyond the engineering and visualization areas. Increasingly we will see VR techniques become an accepted part of applications without the current focus on the technology for its own sake. Improved hardware performance will allow many of the enabling requirements of VR to be incorporated into the standard hardware and software environment of desktop systems.

Selected papers from the conference will be published in a book by Springer. Next year's workshop will be held in Vienna on 31 May - 1 June 1999. The Call for Papers is available at http://www.cg.tuwien.ac.at/conferences/egve99/cfp.html.

David Boyd
CLRC , Rutherford Appleton Laboratory
D.R.S.Boyd@rl.ac.uk