Problem
Statement and Objectives
Two ongoing research interests of the college are
the documentation of historic sites and the development of immersive
visualization systems. The work on historic site documentation is exemplified
by the documentation of Montezuma Castle A, a cliff dwelling site in central
Arizona, and the ongoing work to document the Pointe du Hoc site in
Normandy. The work in immersive
visualization has resulting in the development of several operational prototype
systems and supporting software (Parke, 2002).
The purpose of this proposal is to initiate a pilot
project that will exploit the synergistic relationship of these two
activities. The thrust of the project
is the development of an interactive immersive visualization based on the site
documentation data gathered for Montezuma Castle A. This project will benefit both activities; developing a better
understanding of the use of immersive visualization in site documentation, and
developing a better understanding of the immersive visualization capabilities
needed to successful portray such historic sites.
The project will explore, using this specific
example, the use of immersive visualization as a means to present and
understand such historic sites. Many
sites, such as this one, are no longer accessible to the general public. An immersive visualization would provide an
exciting opportunity to explore and ‘experience’ the site. Since the cost of
installing and operating such immersive systems has decreased dramatically in
recent years, the use of such immersive visualizations is becoming feasible for
installation in venues such as museums and visitor centers.
Specific
objectives of the proposed project include:
1)
organization
and translation of the collected site data into forms suitable for immersive
visualization,
2)
development
of software enhancements required to facilitate this type of immersive
visualization,
3)
development
of an effective operational prototype that will serve as both an educational
tool and as a demonstration example for seeking additional funding,
4)
verify
that the resulting visualization is a faithful representation of the site,
5)
serve
as the basis for at least one, probably two, MS theses,
6)
foster
the development of several publications.
Immersive
Visualization of Historic Sites
While viewers of recent PBS and History Channel
programs are seeing the growing use of computer visualization as part of the
explanations and a number of real time historic site walkthrough visualizations
have been created, the use of immersive visualization for historic sites is
rare.
The proposed work draws on recent and ongoing research activities of two groups in the College; historic site documentation done through HRIL, and the development of immersive visualization systems done through the Visualization Laboratory.
Castle
A at Montezuma Castle National Monument is a 12th c. Sinaguan cliff
dwelling in central Arizona. In 1951 public visits to the building were
closed to protect the building from catastrophic damage. As a result,
public interaction with the building is limited to a view from 40 feet below
and 200 feet away.
In
2002, the Historic Resources Imaging Laboratory was asked to create accurate 2D
HABS level drawings of the Castle A for preservation and archive
purposes. Two field seasons and two years of drawing have resulted in 20
sheets of drawings that will constitute the only visual interpretation of the
building other than photographs and a short video produced in the 1990’s.
Whether these drawings will be made available to the public is a choice for the Park Superintendent but even if they are available an experience of the drawing is not like an experience of the building. At our final meeting with the Park Superintendent we agreed that both the park and the public would benefit greatly from a more natural 3D visualization of the site. The need of the park service for ‘some kind’ of virtual visitation of Castle A provides a practical seed for our investigation into immersive environments.
While standard
visualization techniques provide ‘windows’ into virtual environments, immersive
visualization provides the sense of being ‘within’ and experiencing these
environments. Immersive visualization has, until quite recently, been
associated with very expensive specialized systems used in applications such as
scientific visualization, flight training and petroleum exploration where the
benefits justified the expense. We are focused on spatially immersive systems
such as the CAVE concept initially developed at the University of Illinois at
Chicago (Cruz-Neira, 1993).
Current and near
future technologies and computational economics allow the development of better
and more cost effective spatially immersive visualization
systems. In recent years, low cost
commodity projectors have been replacing the expensive projectors and commodity
PC based graphics systems have been replacing the expensive graphics system
previously used.
Spherical domed display surfaces, requiring
specialized optics, have been used for many years in flight training simulators
(Reno, 1989) and dodecahedron approximations to spherical projections have been
developed (McCutchen, 1991). An
emerging concept has been to develop immersive visualization systems utilizing
modular polyhedral display surface structures that are good approximations to the
ideal display sphere. A high performance
commodity graphics processor is included for each display surface facet
(Hereld, 2000). The result is a
powerful, distributed spatially immersive visualization system.
The faceted display
elements may be arranged in a number of possible configurations. There are a number of polyhedral
configurations whose faceted surfaces are good approximations to the ideal
spherical display surface. These
polyhedron require from 12 up to 60 or more planar faces (Holden, 1971)
(Wenninger, 1971).
Examples of such
systems include the GarnetVision prototype developed by Iwata (Iwara,
1996) which used a 12 facet rhombic dodecahedron to form a fully immersive
system. Another, commercial system, has
been developed by Link Simulation Systems (Dugdale, 1999). This system, called SimuSphere, is
based on a pentagonal dodecahedron facet structure. Our approach is focused on the 24 facet Trapezoidal
Icositetrahedra (Parke, 2002).
To date we have developed two three-facet
operational prototypes. We are
currently working on a seven facet operational prototype. The seven facets will be a slightly modified
subset of the 24 facet polyhedron. This
version will have a nearly 180 degree horizontal and about 90 degree vertical
field of view. Development of the prototypes has involved detailed simulation, physical
structure design, physical fabrication and assembly, supporting software
design, and software implementation.
In recent years, several open source software
development environments that provide the basic utility services and system
support software upon which specific applications can be built have been
created to support the development of immersive visualization systems. These include VR Juggler (Bierbaum, 2001)
(VR Juggler, 2004), Syzygy (Schaeffer, 2003), and OpenSG (OpenSG, 2004).
1) The first step is to organize and transform the
collected image and 3D geometric data into a form suitable for immersive
visualization. The collected data
includes video, digital photographs, Total Station measured 3D reference
points and hand measured 3D data, which was originally collected to support the
creation of 2D HABS level drawings.
This information along with the generated HABS drawings must be
converted into data files suitable for the immersive visualization system. This
means creating appropriate 3D polygonal surface data in .obj file format and
creating the required surface texture files.
2) For this project, some modifications and
enhancements to the existing immersive visualization software will be
required. These enhancements will
include additional interaction capabilities, animation control and audio
support.
Specific interaction enhancements will include
allowing choice of season and time of day.
Since this site evolved through several stages, allowing interactive
selection of the specific evolution stage to be portrayed should be supported.
Also, providing the ability to point at or select specific objects is
desired. An informational audio clip
could be triggered by selecting specific objects or locations within the
site. In addition, an interactive
virtual flashlight or lantern will be needed to explore interior spaces.
The inclusion of animated elements in the site model
is desired. These elements could be
representations of natives moving through the site, smoke, fires, cloud
shadows, etc.
3) Finally, the validity and accuracy of the
visualization must be established.
Evaluation of the visualization is needed to ensure that it is a true
representation of the site and not misleading.
The purpose of this proposal is to initiate a pilot
project that will exploit the synergistic research activities of faculty in
both HRIL and Visualization. This
project will benefit both activities; developing a better understanding of the
use of immersive visualization in site documentation, and developing a better
understanding of the immersive visualization capabilities needed to successful
portray such historic sites.
Faculty of the college unfamiliar with immersive
environments will be able to experience its value through the efforts of this
project. They may then be inspired
about the applicability of this tool to their teaching and research needs. These ideas would likely lead to further
grant development for use of this equipment.
It is expected that this work will serve as the
basis for at least two publications, one contributing to the historic site
documentation literature and the other a contribution to the field of immersive
visualization. Journals such as APT Bulletin and Vernacular Architecture Forum
are at least two possible journals for this type of work. The annual IEEE Visualization and VR
conferences are other possible publication venues.
Since the cost of installing and operating immersive
visualization systems has decreased dramatically in recent years, the use of
such systems is becoming feasible for installation in museums, visitor centers
and other exhibition venues.
Potential to Enhance Current College Programs,
Themes, Priorities
The purpose of this proposal is to initiate a pilot
project that will exploit the potential synergistic relationship of the
activities of HRIL and Visualization.
We are requesting $7,500 to support one graduate
student for eight months during the late spring, summer and fall of 2005 –
April 15 through December 15. This
student will focus on data conversion and software development.
The knowledge and expertise gained from this project
will feed back into courses like Arch 446, Arch 646, and Arch 647, all of which
utilize efforts in historic documentation as an educational foundation. Courses such as VIZA 616 and VIZA 658
address issues in real time immersive visualization. This project will provide specific example material to illustrate
concepts germane to these courses and perhaps challenge that conceptual base.
Visualization has long been tied to Historic
Documentation. The current
visualization standard is 2D drawings.
It is slowly moving towards 3D models but it will take some time for
this to overtake 2D drawings as a standard.
This research would be groundbreaking for Historic Documentation and
only possible with the combination of the faculty and students in the
Architecture and Visualization programs.
This interdisciplinary team will be developing a new understanding of
the use of immersive visualization in site documentation, and also developing
an understanding of the immersive visualization capabilities needed to
successful portray such historic sites.
Follow-On Funding
List other potential outside sources
Plan for seeking outside funding for follow-on work
The strategy is to use this pilot project as a
demonstration of what is currently possible in the use of immersive visualization
as a way for the public to remotely ‘experience’ historic sites. This is especially true for sites that are
not accessible to the public. The project will likely uncover aspects where
further research and development is needed.
Target groups include the National Park Service,
museums such as the new Native American Museum, and other exhibition venues.
NSF has recently indicated interest in a related area by funding a two million
dollar effort to develop better computer modeling tools for archeological
sites. Since the Pointe du Hoc site is
another candidate for immersive visualization, groups interested in that site
would also be funding targets.
The timetable for seeking such funds would be the
fall of 2005 as the results of this project begin to appear and can be
demonstrated.
Describe what has been accomplished with any research funds received during the past three years.
1) The development of the immersive visualization
systems has been supported by a three-year Texas A&M TITF infrastructure
development grant (8/02-8/05). This
$165,000 grant is partially due to initial work supported by earlier CRIC seed
funding.
We are currently in the
operational prototype and initial application development phases of this
project. Development of the prototypes has involved detailed simulation,
physical structure design, physical fabrication and assembly, supporting
software design, and software implementation.
We have developed two operational prototypes. One is a three facet section of the 24 facet
polyhedron described above. The other prototype also has three display facets
forming a section of a 10 facet surrounding cylindrical structure. We are currently working on a seven facet
operational prototype.
2) The two-year site survey and subsequent HABS
drawing documentation of the Montezuma Castle A conducted by the HRIL was
funded by the National Park Service.
3) The current HRIL based Pointe du Hoc site
documentation effort has received support from a number of sources. The data developed from this effort will be
another excellent candidate for visualization including immersive
visualization.
References
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Cruz-Neira,
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J., et al., 1999. Current developments in visual display technology for fighter
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