The Representation of
Geographical Information in VRML.
Monday, February 16, 1998. Monterey CA
I gave a short intro, in which I described a little bit about the genesis of the GeoVRML WG and the issues we are interested in discussing.
We then had a short intro session in which the attendees introduced themselves.
During this time, a contact sheet was distributed.
The first presenter was Theresa-Marie Rhyne <firstname.lastname@example.org>,
the Director of the SIGGRAPH
Carto Project., which was formed and funded by SIGGRAPH
to attempt to bridge the perceived gap between the cartographic and computer
She gave a short description of the Carto Project and of a study that they
commissioned to survey the cartographic community on its access to and
use of computer graphics and visualization tools. They concluded that this
community did have access to a wide variety of tools (primarily at the
low-end) and was very actively interested in more advanced data presentation
Theresa handled a few questions and pledged cooperation between the
Carto Project and the GeoVRML WG.
The second presenter was Don Brutzman <email@example.com>,
a professor at the Naval Postgraduate School in Monterey, and a member
of the VRML Consortium Board of Directors (and after Monterey, the V.P.
Technology of the VRML Consortium). He passed the presentation on
to a student, Greg Leaver <firstname.lastname@example.org>, who presented
the Monterey Bay Modeling Group's "Virtual Monterey Bay," a virtual world
derived from real bathymetric data measuring the ocean floor in the Monterey
Bay, one of the richest areas of marine life in the US. This VRML
world is in the planning stages and is being designed to be useful to both
scientists and the general public (they are collaborating with the Monterey
He then described their plan, which involves tiling the bathymetric
data over a 150x150 km area. The underwater terrain is represented
in VRML as an LOD hierarchy of tiled terrain in which each tile is <100K.
The next presentation was by
Farid Mamaghani <email@example.com>
who described the SEDRIS project.
This is a US Defense Department standardization effort
for the representation and manipulation of datarelevant to simulation
and training environments. SEDRIS stands
for "Synthetic Environment Data Representation &
Interchange Specification." Reading "synthetic environment"
as "virtual reality," we can see the relevance to our community in
that they are standardizing georeference and space-time sequencing
of real-world data. To that end, they are developing and freely distributing
tools for managing their standardized data formats.
We were then given a short overview class on
geodesy and geographical coordinate systems by
Ralph Toms <firstname.lastname@example.org>
who is developing the coordinate system library for SEDRIS.
He discussed Earth Reference Models (ERMs), World Coordinate Systems,
and the difficulties and limitations in converting
from one to others. He gave a three to four month timeline before
the high-performance, high-accuracy software he's working on will be
completed and publicly available.
The last speaker was Martin Reddy <email@example.com>, who spoke
about TerraVision, the terrain visualization system we're developing at
SRI. It is a high speed, very high bandwith system for visualizing extremely
large (10-100GB) terrain data sets (typically hundreds of square kilometers
with elevations at 30m resolution and imagery at 1m). The first version
of it was built using OpenGL and portable C on high-end SGI workstations
using an application-specific data format. The second version, which
he discussed also uses OpenGL, but we have adopted VRML as the external
data representation and have developed our own EXTERNPROTOs for georeferencing
and managing topology in very deep level-of-detail hierarchies. We
too are managing tiled terrain, but by explicitly representing the neighbourhood
topology of tiles, we can dynamically modify the
geometry (in TerraVision) we avoid the surface tears when LOD levels
change within a scene. A CD of one of our sample VRML tile sets was
distributed at the meeting, and was snapped up like hotcakes.
Lee Iverson <firstname.lastname@example.org>
Last updated: Tuesday, 21-Jul-1998 15:13:05 PDT