CyberStage - An Advanced Virtual Environment
by Henrik Tramberend, Frank Hasenbrink, Gerhard Eckel, Ulrich Lechner
and Martin Göbel
Virtual Environments now have come
into age. Following the head bounded technology of the first days, now
industrial applications in the Virtual Reality-Labs of the automotive
industry are basically using stereo projection type systems like standard
single screens, multiple screens.
The CyberStage is a 4 side room size stereo display system an
enhanced CAVE-like-set-up which creates the illusion of immersion
within a computer generated environment. Users may not only see large virtual
spaces but also hear spatially distributed sound sources and experience
vibrations associated with physical models like gravity.
GMD's research aims to develop intuitive man machine interfaces and
cooperation metaphors for humans in virtual environments. Projection systems
like the Responsive Workbench or the CyberStage allow a direct and body
centred interaction within virtual worlds as well as team work in small
groups. Due to these possibilities industrial applications today see many
advantages in projection systems rather than in head coupled systems. GMD
has installed the first CyberStage installation in late 1996 in its labs
near Bonn. At CeBIT'97 a second, improved version was presented to the
public.
User immersed in a virtual world are physically standing within the
display system of the stage. Currently, the stage size is a 3 x 3 meter
ground on which the virtual space is generated by high performance graphics
workstations. CyberStage is a room size immersive virtual environment for
3-5 users. Compared to CAVEs, the image quality within the Stage is much
more improved and an 8 channel audio display is integrated in the system.
Furthermore, the significant characteristic of the stage is the acoustic
floor which allows to generate the sense a vibrating ground to the users.
On this basis, the CyberStage allows to address more human senses in any
application of virtual environments than the traditional caves.
AVOCADO is the virtual environment operating software, design and
implemented by GMD since summer 1996. AVOCADO supports distributed virtual
environments. It is written in C++ based on SGI Performer and allows the
definition of object behaviour in a scripting language (Chez Scheme).
In GMD's current installation, AVOCADO is operating a 2 pipe Onyx Infinite
Reality which generates 4 stereo pairs for the 4 side projection.
CyberStage has a size of 3 x 3 meters for the ground projection system.
Four acoustic elements (150W each) generate vibrations within very low
frequencies. Three wall size rear projection systems are installed orthogonal
to the ground, each with a size of 3 x 3 meters. Thus, four sides of a
27 m3 room are used for displaying visual worlds in stereo by Electrohome
Marquee 8500 projectors. A dual pipe Onyx IR workstation (4 RM6 and Sirius
video option) is generating 8 user controlled images in a frame rate between
10-50 Hz. The user position on the stage is tracked with Polhemus Fastrak
sensors. Crystal Eyes shutter glasses are used for stereo image reception.
The display resolution is 1024x768 pixels at 120 Hz for each of the 4 displays.
While the first CyberStage installation was fixed in a building, the
new version has been developed for 'mobile' usage. It consists of 5 modules
(each about 3x3x3 meters) which can be assembled in a short time. Broadband
communi-cation to GMD near Bonn allow to experience distributed, virtually
shared environments. Both CyberStage installations use a wooden skeleton
to minimize noise for the electromagnetic tracking.
An 8-channel-surround-sound system is fed by the room acoustic software
Spatialisateur of IRCAM, which is processed on a multi media workstation
independently from the acoustic floor. The AVOCADO software allows to import
live video sources as well as prefabricated animations into virtual worlds.
Virtual actors, developed by GMD's partner, plan_b, can be found on the
Stage in both ways, either in an online performance or in a preproduced
manner. Interaction within virtual environments is based on electromagnetic
tracking using devices such as 3D pointers or 3D joysticks. Interaction
feedback, ie response of objects, are defined as object behaviour within
the object data structure and can be exported to a different site within
a distributed virtual environment set up.
Interior design of a Volkswagen Sharan.
A number of applications have already been developed and tested within
the CyberStage environment. Scientific visualization of multidimensional
simulation results from fluid dynamics and crash simulations has shown
how to support the understanding of complex physical phenomena. Simulation
and visualization of protein structures and the 4 dimensional display of
mathematical functions (like projective planes) belong also to the applications
which are currently under investigation at GMD.
Applications shown previously included the audio-visual simulation of
a novel operation theatre concept from the German Max Dellbrueck Center
in Berlin as well as a walk through in an audio-visual gallery of the Museum
for Architecture. Engineering data like the interior and exterior design
of a Volkswagen Sharan has also been imported and tested by automotive
design teams.
The fantastic world of CAVELAND has been developed to demonstrate the
audio visual potentials of the CyberStage. Virtual actors guide the visitor
through a world of adventures. Landscapes and caves from fire and ice build
impressive wide and narrow spaces. Virtual transportation systems, audible
spaces and virtual gravity introduce to a new dimension of virtuality within
the Stage.
Cyberstage and caveland have been developed in close cooperation with
plan_b, Medienwerkstatt Köln, KHM Köln, ICEM Iowa State University,TAN.
CAVE is a registered Trademark of the University of Illinois. Reponsive
Workbench (RWB) is a registered Trademark of GMD.
Please contact:
Martin Göbel - GMD
Tel: +49 2241 14 2366
E-mail: martin.goebel@gmd.de
