Immersive Telepresence
by Vali Lalioti, Frank Hasenbrink and Olaf Menkens
The aim of Immersive Telepresence is to provide geographically
dispersed groups of people the possibility to meet and work within
projection-based Virtual Reality Systems as if face-to-face.
In our approach participants not only meet as if face-to-face,
but also share the same virtual space and perform common tasks,
in order to reach a common goal. For this purpose live stereo-video
and audio of remote participants is integrated into the virtual
space of another participant, allowing a geographically separated
group of people to collaborate while maintaining eye-contact,
gaze awareness and body language.
Participants can use a wide range of Projective Virtual Reality
Systems, such as CyberStage, Responsive Workbench, Cooperative
Responsive Workbench and Teleport, resulting symmetric or asymmetric
collaboration scenarios. The scientific approach includes stereo
camera calibration, in order to obtain the camera parameters,
which are then used for integrating the stereo-video into the
virtual space, while preserving the stereo-effect and perspective
for the tracked viewer.
Immersive Telepresence in Cyberstage
The first prototype of the environment was demonstrated in October
1997. A remote participant captured with a stereo camera was chroma-keyed
into a 3D virtual space, being virtually present in a 3D virtual
environment displayed in the CyberStage. For the first time ever
a fully immersed 3D virtual teleconference was demonstrated based
on virtual studio techniques of keying video images into computer
generated scenes.
The imported image sequences had to pass several Silicon Graphics
video options, delay units and chroma keyers before taken as a
dynamic texture into the AVOCADO Software Framework. AVOCADO handled
the positioning and display of the remote participant within the
virtual world of an operation theater. The remote participant
gave instructions to CyberStage visitors on how to operate various
devices and instruments of this virtual operation theater.
Cyberstage and Immersive Telepresence
In integrating the live audio of the remote participant the spatial
audio functionality of AVOCADO was used (see previous article). The live audio was attached as an audio source to the geometry
representing the live stereo-video in the virtual world. Therefore,
audio from the remote participant was spatialized, and was increasing
in volume or fading away in direct response to moving nearer or
further away from the video image of the remote participant in
CyberStage. This greatly enhances the immersive telepresence effect.
Immersive Telepresence at the Cooperative Responsive Workbench
The Cooperative Responsive Workbench extends the Responsive Workbench
with a vertical screen, thus enlarging the viewing frustum and
allowing remote collaboration and Immersive Telepresence.
On the vertical screen of the Cooperative Responsive Workbench
a user could see and communicate in real-time with a person or
team located at a different place, and at the same time view and
manipulate 3D stereoscopic virtual objects (ie. the model of a
car, seismic data for mining, medical data of a patient etc).
Immersive telepresence can be used in a variety of application
areas such as medical and geoscience applications (see article in ERCIM News No.37).
Please contact:
Vali Lalioti - GMD
Tel: +49 2241 14 2787
E-mail: vasiliki.lalioti@gmd.de
Frank Hasenbrink - GMD
Tel: +49 2241 14 2051
E-mail: frank.hasenbrink@gmd.de
Olaf Menkens - GMD
Tel: +49 2241 14 2362
E-mail: olaf.menkens@gmd.de
