The Bridge - Issue 1, 2023 - 17

(a)
(b)
(c)
Figure 4: (a) The Leica RTC 360 scanning inside of the mercantile at Sakura Square [photo credit: Jesse Kuroiwa], (b) DJI Matrice 300 Pro with a
Zenmuse L1 Lidar package on a test flight at Chatfield State Park model airplane airfield, Colorado, and (c) Artec Eva structured light scanner at
Philipse Manor Hall, New York.
VI. Increased Accessibility and Virtual Tourism
Point clouds generated by structured light, ground-based
Lidar, and drone-based Lidar can be combined into a
single, unified point cloud or broken into separate, distinct
architectural elements. The point cloud(s) will follow
different workflow paths based on project needs, with the
original point cloud always available to meet future yet-tobe-defined
requirements. For example, when developing
a set of HABS drawings, the point cloud is divided into
manageable architectural elements that will be used to
create the measured drawings. In the workflow, the desired
portion of the point cloud (e.g., commercial, residential,
worship, landscape) is exported and then imported into
programs such as AutoDesk CAD or Revit. The tools in
AutoDesk can snap to the point cloud and reduce it to a
measured drawing in a plan or profile view.
Another workflow path is to mesh the point cloud into a
mesh or watertight model using programs such as Leica
3DR, Blender, or MeshLab. These meshed models can be
3D printed or phototextured and displayed in Augmented
Reality (AR) or Virtual Reality (VR) using devices such as
a web-based WebXR viewer, an Oculus, or a Microsoft
HoloLens (to name just a few available viewers). The
structured light surveys of the papier-mâché ceiling at
Philipse Manor Hall were inverted and used to create
3D-printed molds. The molds were used to make papiermâché
replicas of the 53 distinct elements in the ceiling that
were then installed on a ceiling at the Schuyler Mansion.
Beyond creating a high-fidelity digital record for historic
preservation, our research addresses accessibility and
virtual tourism. Historic places open for visitation often
have inaccessible areas to the public and other sites not
accessible based on mobility. Interpretive signs can aid
in bringing some experience to these hard-to-access
spaces, but 3D point clouds and meshed models with
photorealistic texture can bring these spaces virtually to
the visitor. Adding a kiosk with a monitor, an augmented
reality device, virtual reality device, or all three gives visitors
a chance to explore all areas while visiting a historic site.
These devices can also reconstruct missing elements and
even provide visitors with views of the site through time.
Visitors to the General Schuyler House in Schuylerville, NY
get to tour the house and walk the grounds around the
house. Missing from such a visit, is experiencing all of the
mills, barns, and quarters of enslaved people and workers,
all of which no longer exist on the landscape. All of these
elements can be digitally reconstructed and geolocated
in a WebXR viewer, where visitors with a tablet or phone
can view these structures while walking the property.
Experiencing augmented and virtual reality while physically
visiting an historic site can bring a deeper understanding of
the physical context; however, virtual visitors can also visit
these sites from afar.
REFERENCES
[1] Cox, Ronald, " Distance-Measurement, Electromagnetic, " pp.
177-180 in Robert Bud and Deborah Warner, eds., Instruments of
Science (New York and London, 1998).
[2] Spring, Adam P. " A history of laser scanning, part 1: space and
defense applications. " Photogrammetric Engineering & Remote
Sensing 86.7 (2020): 419-429.
[3] Burns, John A., ed. Recording historic structures.
John Wiley & Sons, 2003.
[4] https://www.nps.gov/hdp/standards/index.htm
[5] https://scantech-international.com/blog/timeline-of-3d-laserscanners
[6]
Rogers, Michael 'Bodhi, Ryan Bouricius, Denis Shine, Stephen
Mandal, and Scott Stull. " Laser-Scanning Trim Castle. " Archaeology
Ireland 32, no. 3 (2018): 34-39.
[7] https://www.geospatialworld.net/news/leica-geosystems-launchesleica-hds6000-scanner/
Michael
" Bodhi " Rogers is a Professor
and Chair in the Department of Physics at
the University of Colorado Denver. Along
with being a Ph.D. physicist he is also a
registered professional archaeologist. He
specializes in below ground imaging such
as ground-penetrating radar, magnetometry,
and earth resistance, and 3D model creation
using photogrammetry, structured-light
scanning, and time-of-flight scanning. His research includes the
creation of 3D models of cadaveric arms to document efficacy for
new wrist and elbow surgeries, documenting historic structures,
and developing methods of viewing LiDAR data using a web-based
viewer and WebGL.
Ekaterini Vlahos is a Professor of
Architecture at the University of Colorado
Denver. As a licensed architect and former
Director of the Center of Preservation
Research (CoPR), her research focuses
on developing innovative methods using
cutting-edge technologies to promote
informed decision-making for preservation
and sustainable design. She is the recipient
of the Preservation Leadership Award and, in collaboration, the
Stephen H. Hart Award for outstanding preservation projects.
Professor Vlahos serves on the CIPA International Scientific
Committee of ICOMOs and the National Council for Preservation
Training and Technology Board.
HKN.ORG
17

https://www.nps.gov/hdp/standards/index.htm https://scantech-international.com/blog/timeline-of-3d-laser-scanners https://scantech-international.com/blog/timeline-of-3d-laser-scanners https://www.geospatialworld.net/news/leica-geosystems-launches-leica-hds6000-scanner/ https://www.geospatialworld.net/news/leica-geosystems-launches-leica-hds6000-scanner/ https://hkn.ieee.org/

The Bridge - Issue 1, 2023

Table of Contents for the Digital Edition of The Bridge - Issue 1, 2023