in heritage and museum sciences

Photogrammetric Modeling of Museum Collections for Researcher Access

by

Megan Ostrenga, B.S.Ed.

A Thesis

In

Heritage and Museum Sciences

Submitted to the Graduate Faculty of Texas Tech University in

Partial Fulfillment of the Requirements for

the Degree of

MASTER OF ARTS

Approved

Dr. Stance Hurst Chair of Committee

Dr. Peter Briggs

Dr. Scott White

Mark Sheridan

Dean of the Graduate School

August, 2020

Texas Tech University, Megan Jill Samsela Ostrenga, August 2020

ii

TABLE OF CONTENTS

ABSTRACT .............................................................................................................. iv

LIST OF TABLES ..................................................................................................... v

LIST OF FIGURES .................................................................................................. vi

CHAPTERS

I. INTRODUCTION .................................................................................... 1

Research Question............................................................................. 2

Background Information ..................................................................... 2 Museum of Texas Tech University .......................................... 2 Fred Miles Casas Grandes Collection ..................................... 4 3D Modeling Museum Objects for Research .......................... 6 Significance of Research ......................................................... 9

II. PHILOSOPHICAL PERSPECTIVE ...................................................... 10

Background ...................................................................................... 10 Digital Replication and Documentation of Heritage .............. 10 Research Quality 3D Models ................................................. 13 Research ................................................................................ 13 Museum Practices.................................................................. 17 Goals and Objectives ....................................................................... 18

Ending Comment .............................................................................. 19

III. METHODOLOGY ................................................................................. 20

Literature Review: Intersection of Museums and 3D Technology .. 20

3D Modeling Process ....................................................................... 20

Measurement Study ......................................................................... 35

Survey ............................................................................................... 36

Advantages and Disadvantages of 3D Modeling ............................ 44

Concluding Remarks ........................................................................ 44


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IV. RESULTS ............................................................................................. 46

Measurement Study Analysis .......................................................... 46

Survey Analysis ................................................................................ 53

V. DISCUSSION ....................................................................................... 67

Measurement Study ......................................................................... 67

Survey ............................................................................................... 69

Benefits and Limitations of the Methodology................................... 72

Significance of Results ..................................................................... 73

VI. CONCLUSION ...................................................................................... 74

Concluding Remarks ........................................................................ 75

REFERENCES ....................................................................................................... 76

APPENDICES

A: IRB APPROVAL LETTER.................................................................................. 82 B: CASAS GRANDES CERAMICS DESCRIPTIONS ........................................... 84 C: PHOTOGRAMMETRY WORKFLOW ............................................................... 89 D: MAXIMUM RIM DIAMETER MEASUREMENTS FOR PHYSICAL AND VIRTUAL VESSELS ............................................................................................... 90 E: MINIMUM RIM DIAMETER MEASUREMENTS FOR PHYSICAL AND VIRTUAL VESSELS ............................................................................................... 93 F: BACKGROUND OF SURVEY RESPONDENTS .............................................. 96 G: EMAIL TO RESEARCHERS/IRB STATEMENT ............................................101


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ABSTRACT

Museums seek ways to increase access to their collections while

minimizing adverse impacts on those same collections. This study examines how

the creation of three dimensional photogrammetric models can impact researcher

access to museum collections and suggests through example how to incorporate

photogrammetric modeling into museum collection practice.

Sixty Casas Grandes ceramic vessels from the Fred Miles held-in-trust

collection at the Museum of Texas Tech University were 3D modeled as a case

study to determine the viability of using photogrammetric models for research.

Two focus groups were used to determine the usefulness and reliability of the

models. The first focus group was comprised of five graduate student assistants

who measured both the physical and virtual vessels in order to determine the

accuracy and precision of analog measuring versus digital measuring. Ultimately,

measurements taken on the virtual vessels were more accurate and precise than

measurements taken on the physical vessels. The second focus group was

comprised of twenty-four ceramic researchers, Casas Grandes experts, and

digital heritage specialists who evaluated and documented the virtual vessel’s

potential for use in research as well as the viability of similar modeling projects.

These researchers found the models to at least meet their expectations for

overall-quality needed for research.


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LIST OF TABLES

Table 1.1. Inventory of Fred Miles Casas Grandes Collection ............................... 4 Table 1.2. Inventory of 3D Modeled Casas Grandes Vessels ................................ 4 Table 3.1. Photography specifications used to capture photogrammetric images of the vessels in the Fred Miles Casas Grandes Collection ... 22 Table 4.1. Mean of the differences (Physical – Virtual Maximum Rim) and standard deviation for each person’s maximum rim diameter measurements ...................................................................................... 47 Table 4.2. Mean of the differences (Physical – Virtual Minimum Rim) and standard deviation for each person’s minimum rim diameter measurements ...................................................................................... 49 Table 4.3. Maximum rim diameter coefficient of variation p-values for each person .................................................................................................... 50 Table 4.4. Minimum rim diameter coefficient of variation p-values for each Person ................................................................................................... 50 Table 4.5. The mean and standard deviation of all measurements for each measurement type ................................................................................ 51 Table 4.6. Coefficient of variation p-values for each measurement type ............. 52

Table 4.7. List of questions from the researcher survey ....................................... 53


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LIST OF FIGURES

Figure 1.1. Example of the 3D point cloud generated from 2D images; the blue rectangles demonstrate the location around the object from-which an image was photographically recorded.............................................. 8 Figure 2.1. A picture from SmugMug (2014) of a color checker card with Vivien Sin’s Of Red (2013), oil-on-canvas painting. The color checker card facilitates color calibration of photographs in post-processing ........... 12 Figure 2.2. Casas Grandes Ramos Polychrome Effigy Jar (TTU-A10-53) viewed online in SketchFab ................................................................ 14 Figure 2.3. Casas Grandes Ramos Polychrome Effigy Jar (TTU-A10-53) viewed in Augmented Reality from a mobile device .......................... 15 Figure 2.4. Casas Grandes Mini Playas Red Footed Cup (TTU-A10-18) viewed in Virtual Reality through a mobile device utilizing Google Cardboard ........................................................................................... 16 Figure 2.5. A Folsom projectile preform edited in TinkerCAD to include braille and three Ls indicating the Lubbock Lake Landmark logo (Hurst et al., 2017) .............................................................................................. 16 Figure 3.1. Photography set-up with light tent, lamps, and camera mounted on a tripod.................................................................................................. 26 Figure 3.2. A point cloud with data from overlapping images; the blue rectangles represent locations around the object from which each image was captured ............................................................................. 27 Figure 3.3. A Plainware Bowl (TTU-A10-22) rotated to five different angles to capture photographically a series of overlapping images of the entire vessel ......................................................................................... 28 Figure 3.4. Five sub-chunks containing 18 to 21 pictures each for a total of 96 images ............................................................................................. 29 Figure 3.5. Using the Intelligent Scissors tool, the object was selected (left) and inverted (right) creating a mask around the object ............................ 30 Figure 3.6. An example of the range of angles that required masks for each sub-chunk ............................................................................................. 30 Figure 3.7. An example of the images not aligning ............................................... 31


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Figure 3.8. The dense cloud with extra points from the background (left) and the dense cloud once the background has been excluded (right)...... 32 Figure 3.9. A sample of each of the four processes: 1) the point cloud generated from photo alignment; 2) the dense point cloud model estimating depths; 3) the polygonal model, or mesh, generated using the depths from the dense cloud; 4) the texture showing surficial details ...................................................................................... 33 Figure 3.10. Measurement of the physical vessel (TTU-A10-60; Ramos Black Jar) using a caliper and measurement of the virtual vessel using the digital ruler tool. The measurements differed by 0.01 millimeter ............................................................................................ 34 Figure 3.11. A view of the Anthropology collection on SketchFab ....................... 38 Figure 4.1. One-way analysis of maximum rim diameter measurements (Physical – Virtual Maximum Rim) by person ..................................... 48 Figure 4.2. One-way analysis of minimum rim diameter measurements (Physical – Virtual Minimum Rim) by person ...................................... 49 Figure 4.3. One-way analysis comparing the coefficient of variation for each measurement type ............................................................................... 51 Figure 4.4. Background of survey participants ...................................................... 55 Figure 4.5. Length of time each respondent had previously studied ceramics .... 56 Figure 4.6. Survey participants’ prior experience with 3D modeling..................... 57 Figure 4.7. Number of models each respondent viewed during this study........... 58 Figure 4.8. Respondents’ rating for model resolution ........................................... 59 Figure 4.9. Respondents’ rating for model color ................................................... 59 Figure 4.10. Respondents’ ratings for overall quality ............................................ 60 Figure 4.11. Respondents’ opinions on how these 3D models could be used For research ....................................................................................... 61 Figure 4.12. Areas in which respondents were interested in using models in future studies ...................................................................................... 63


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Figure 4.13. Responses from respondents with prior 3D modeling experience (left) vs. respondents with no prior 3D modeling experience (right) for model resolution ........................................................................... 64 Figure 4.14. Responses from respondents with prior 3D modeling experience (left) vs. respondents with no prior 3D modeling experience (right) for model color. .................................................................................. 65 Figure 4.15. Responses from respondents with prior 3D modeling experience (left) vs. respondents with no prior 3D modeling experience (right) for overall model quality ..................................................................... 66


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CHAPTER I

INTRODUCTION

Museums seek to increase access to their collections for research while

minimizing adverse impacts on those same collections. This study explores how

the creation of three-dimensional (3D) digital models created with

photogrammetry can impact access to museum collections and suggests through

example how to incorporate this model-developing process into museum

collection practice. This thesis, a case study in the growing field of digital

heritage, focuses on 1) documentation and input; 2) presentation and output; 3)

digital content management; and 4) analysis of photogrammetric models (He et

al., 2017).

Sixty Casas Grandes ceramic vessels from the Fred Miles held-in-trust

collection at the Museum of Texas Tech University (MoTTU) were 3D modeled

as a case study to determine the suitability of using virtual models for

research. This study evaluated the usefulness and reliability of the models using

two focus groups. The first group was comprised of five graduate student

assistants at the MoTTU who compared the accuracy and precision of analog

measuring versus digital or virtual measuring. The second group was comprised

of ceramic researchers, Casas Grandes experts, and digital heritage specialists

to evaluate and document the virtual vessels’ potential for use in research

and help determine the applicability of similar modeling projects.


2

Research Question

This study explores if photogrammetric models of museum collection

objects can facilitate access to museum collections for researchers by

fulfilling their analytical needs. The research question is: can virtual

photogrammetric models fulfill the analytical needs of researchers in the place of

hands-on examination of museum objects? A corollary research question is: are

measurements of virtual vessels more or less accurate than measurements

taken from a physical vessel? Measurements taken during the measurement

study and feedback from the researcher survey provide data for addressing the

research questions.

Background Information

Museum of Texas Tech University

The MoTTU was established as the West Texas Museum in 1929 four

years after the establishment of the Texas Technical College (MoTTU, 2018) in

Lubbock, Texas. The MoTTU houses more than eight million objects in collecting

divisions that include anthropology, art, clothing and textiles, history, and

paleontology. The collections at the MoTTU focus on the arts, cultures, heritages,

histories, and sciences of the American Southwest and similar geographic

regions in time and space (Strategic Plan 2016-2020).

This research utilized the Fred Miles Casas Grandes Collection — a West

Texas Museum Association held-in-trust collection which is curated within the

MoTTU’s Anthropology Division. The 115 objects in this collection includes 65

jars, 24 bowls, nine mini vessels, eight effigies, one sherd, and nine other


3

ceramic vessels (Table 1.1). Sixty of these vessels were selected as a

representative sample of the different forms and designs in the collection to

create a variety of 3D models for this study (Table 1.2).

Table 1.1. Inventory of Fred Miles Casas Grandes Collection.

Design Bowl Jar Mini Effigy Sherd Other Total:

Plainware 5 31 8 3 47

Playas Red 5 9 1 2 17

Babicora Polychrome

2 1 1 4

Villa Ahumada

Polychrome 2 5 7

Ramos Black

8 5 1 1 1 16

Ramos Polychrome

2 8 5 1 16

Corralitos Polychrome

1 1

Dublan Polychrome

4 4

Other 1 1 1 3

Total: 24 65 9 8 1 8 115

Table 1.2. Inventory of 3D Modeled Casas Grandes Vessels.

Design Bowl Jar Mini Effigy Other Total:

Plainware 6 12 3 1 22

Playas Red 4 3 1 1 9

Babicora Polychrome

2 1 1 4

Villa Ahumada Polychrome

2 2 4

Ramos Black 5 1 1 7

Ramos Polychrome

2 2 4 1 9


4

Table 1.2. Continued

Design Bowl Jar Mini Effigy Other Total:


1 1

Dublan Polychrome

2 2

Other 1 1 2

Total: 21 25 4 6 4 60

Fred Miles Casas Grandes Collection

The Casas Grandes ceramic collection was sold in 1970 to the West

Texas Museum Association by Gladys Miles of Roswell, New Mexico in her

husband, Fred Miles, name. Fred Miles was an amateur collector of minerals,

figurines, blankets, and pottery. There is no documentation of when or where

these objects were collected by Mr. Miles. A year after Mr. Miles’ death, his wife

sold ~700 minerals to the Texas Tech Geosciences Department and ~120

ceramics to the West Texas Museum for $700 and $1,000 respectively

(Kingman, 1970; Yeats, 1970). The Fred Miles’ Casas Grandes Collection haven

been curated by the MoTTU Anthropology Division as vessels from the Casas

Grandes pueblo.

The Casas Grandes pueblo, also known as Paquimé, is located

in northwestern Chihuahua, Mexico, and was designated an UNESCO World

Heritage Site in 1998. Paquimé was occupied (~1200 - 1450 AD) by a middle-

level society with a wealthy elite class (Whalen and Minnis, 2001:3).

Casas Grandes was first discovered in 1584 by Baltazar de Obregon, the

first European explorer to reach this land (Whalen and Minnis, 2001:27). In 1890,


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Adolph F. Bandelier wrote the first accurate description of the Paquimé site

(Whalen and Minnis, 2001:27-28). Many studies and descriptions of the pottery

took place from the 1920s onward, and Charles diPeso led the Joint Casas

Grandes Expedition (JCGE) from 1958 until 1961 providing a description for

every object he excavated at the site (VanPool and VanPool, 2007:6). DiPeso’s

descriptions are still utilized today to classify ceramic styles of Casas Grandes

ceramics, and, with some additions by Whalen and Minnis, were utilized in the

classification of objects in this study (Appendix B).

In the 1970s, about 15 miles from Nuevo Casas Grandes, the pueblo

of Mata Ortiz grew alongside the ruins of Paquimé. Within Mata Ortiz, Juan

Quezada began creating ceramics similar to those of prehistoric Casas Grandes.

To mark his work, Quezada painted his signatures on the pottery. Due to the

quality and similarity that Quezada’s pottery had to the prehistoric Casas

Grandes pottery, collectors began to gather his work, grind off his signature, and

resell them as prehistoric Casas Grandes ceramics. Due to the popularity of his

work, but denied credit, Quezada began to etch his signature into his pottery to

differentiate it from the vessels being sold as forgeries. In the mid-1980s,

Spencer MacCallum found the etched pottery, and began to sell the Quezada

pottery as Mata Ortiz. The Mata Ortiz pottery proliferated and began to be mass

produced and collected. As a result, vessels must be observed for etched

signatures or areas, especially on the base of the ceramics, where paint has

been ground off in order to determine if the vessels are Casas Grandes

or Mata Ortiz (Hayes et al., 2015: 56). Additionally, ceramics delineated as


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Casas Grandes may not be from Paquimé at all, but are rather from one site

among hundreds that created ceramics in the Casas Grandes tradition during the

same time (Wilson, 2014).

Pottery from Casas Grandes has been a focus of research for

archaeologists for several decades. Studying the ceramics of the Casas Grandes

peoples is helpful towards understanding the beliefs, technologic traits, and

growth and demise of the inhabitants (VanPool and VanPool, 2007:35). The

pottery shows rapidly changing technologic, symbolic, and ritualistic traits as

mirrored by the replacement of pit structures with above ground structures and

new ritualistic architecture (VanPool and VanPool, 2007:35). Further, a

proliferation in ceramics, adoption of irrigation agriculture, and increased burials

also suggest growth in settlement size (VanPool and VanPool, 2007:35).

3D Modeling Museum Objects for Research

Three-dimensional models are typically created through laser scanning or

photogrammetry. Laser scanning uses spatial coordinates gathered through the

recording of the travel time between the emission and reflection of lasers

directed at the surface of an object (Bayram et al., 2015; Moon et al., 2019). The

laser scanner records the travel time as a spatial coordinate and constructs an

image based on the pattern of these coordinates. When the laser scanner

accurately records the coordinates, the measurements of the model are accurate

with an error range of 1-10mm (Moon et al., 2019). The size, movement of the

object, texture, and color, however, can distort the recording of spatial


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coordinates and thus the measurements of the 3D model (Khalaf et al., 2018;

Moon et al., 2019).

In photogrammetry, matching key points found between overlapping

photographs are used to extract digital image data into a spatial point cloud

(Athanassopoulos and Shelton, 2015; Bayram et al., 2015; Khalaf et al., 2018;

Moon et al., 2019; Figure 1.1). The point cloud data is then used to create a

photorealistic model of the object’s surface. Researchers have demonstrated that

the accuracy and precision of models created from laser scanning and

photogrammetry are similar, and each approach is often used in combination to

minimize each’s disadvantages (Bayram et al., 2015; Moon et al., 2019). This

research utilized photogrammetry because color and texture accuracy are

essential for ceramic study.


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Figure 1.1. Example of the 3D point cloud generated from 2D images; the blue rectangles demonstrate the location around the object from-which an image was photographically recorded. Once 3D models are created, they can be viewed by researchers in

multiple ways including on their computer or through augmented reality (AR),

virtual reality (VR), and 3D printing (Freina and Ott, 2015; Akçayır and Akçayır,

2017; Stepp, 2018; SketchFab, 2019). Researchers, therefore, have multiple

ways to view the models for analysis depending on their research needs.

An important aspect of this thesis was the development of research quality

3D models. In this thesis, to be defined as a research quality model, the model

had to be scaled with less than a 0.1 millimeter difference between the model’s

measurements and the physical vessel’s measurements and have no gaps or


9

missing data within the model’s mesh. These aspects are important for

researchers conducting analysis because the models, on the surface, are

complete, and allow for accurate measurements to be taken.

Significance of Research

This research aims to create photogrammetric models of museum

collection objects to determine the suitability of using virtual models for research.

Limitations for this project include imperfect knowledge of the technologies

and finding the best photogrammetry workflow. Benefits from this project may

include increased access to a previously unshared collection for researchers.

Knowledge gained from this thesis explores the viability of using 3D models for

collections management and research by expanding the accessibility of this

collection for researchers.


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CHAPTER II

PHILOSOPHICAL PERSPECTIVE

The framework that guides this research is digital heritage, a developing

intellectual field delineated by scholars from multiple disciplines who are

interested in the intersections between digital technology and heritage (Müller,

2002; He et al., 2017). The United Nations Educational, Scientific and Cultural

Organization (UNESCO) defines heritage as a “…legacy from the past, what we

live with today, and what we pass on to our future generations (2019).” Heritage

includes tangible or intangible objects from the past and the network they once

participated in. The Charter on the Preservation of Digital Heritage (UNESCO,

2003) states that digital representations of heritage and works that are born

digital and that are of enduring value need to be preserved and maintained as

their own form of heritage.

A digital heritage perspective is used to guide this thesis in examining how

photogrammetric 3D models of a museum collection are received by potential

researchers. Results of this research will provide insights into the creation of

photogrammetric 3D objects and their use for research.

Background

Digital Replication and Documentation of Heritage

Digital heritage impacts analog museum practices such as documentation,

research, information management, conservation, and preservation of collection

objects and their related documents (He et al., 2017:335). Specialists in digital


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heritage aim to create and preserve digital resources that will last in perpetuity

(He et al., 2017).

Digital heritage specialists have applied successfully a variety of digital

technologies and methods for replication of heritage (Hirayu et al., 2000; Serain,

2018). For example, Hirayu et al. (2000) replicated, using photogrammetry, 10

Gassho-zukuri houses to demonstrate their architectural specifications and

prevent a loss of their historic construction techniques. In another study, Serain

(2018) discussed how images can replicate pictorial layers added to a canvas to

determine a painting’s physicochemical properties, identify prior alterations or

restorations, and virtually restore colors.

Digital color replication in virtual models has proven to be difficult (Bettio et

al., 2013). Human subjectivity in the observation of colors and lighting of a

photograph or model, and computer monitor or screen settings can distort the

copy (Bettio et al., 2013; SmugMug, 2014). A calibration target or color checker

card captured in an image (Figure 2.1) provides a set of objective or target colors

to calibrate a photograph (Bettio et al., 2013; Sanmartín et al., 2014; SmugMug,

2014). To reduce post-processing time required by such cards, Ozoemenam and

Wang (2016) invented a digital stylus that captures and replicates color through

“optical sensors [housed in the stylus] adapted to accurately capture a color

value from an object or image placed in view of the sensor, the color value

comprising at least a hue value,” during the photographic process. Without an

automated calibration process, however, methods of capturing (i.e. type of

camera, lenses or and color checker card) and methods of viewing (i.e. type of


12

computer monitor, software or projector) still require post-processing calibration

to display accurate colors (Bettio et al., 2013; Sanmartín et al., 2014).

Figure 2.1. A picture from SmugMug (2014) of a color checker card with Vivien Sin’s Of Red (2013), oil-on-canvas painting. The color checker card facilitates color calibration of photographs in post-processing.

In addition to color replication, specialists in digital heritage are studying

applied metrics of digitized objects (Graham et al., 2017; Cook et al., 2019).

Accurate and precise measurements from models is essential for study,

comparison, and conservation (Graham et al., 2017). Graham et al. (2017)

compared structured light scanning, triangulation laser scanning, photometric

stereo, and close-range photogrammetry to determine which method(s) produced

accurate measurements. While there were benefits and limitations for each

method tested, Graham et al. (2017) demonstrated that close-range


13

photogrammetry using an easily repeatable, but precise workflow was the most

effective measuring method. In another study, Quimby et al. (2004)

demonstrated that measurements from computer-based models are accurate,

reliable, efficient, and effective. No studies, however, have compared the

accuracy (similarity between a measurement and its true value) and precision

(similarity of repeated measurements of the same object) of measuring virtual

objects using a computer to measuring physical objects with hand measurement

tools (Lyman and VanPool, 2009:487).

Research Quality 3D Models

Digital three-dimensional modeling replicates heritage based on data

recorded from a physical object to create photorealistic virtual models of an

object’s surface. In this thesis, a research quality 3D model is defined as having

less than a 0.1 millimeter difference between the model’s measurements and the

physical vessel’s measurements and having no missing data within the model’s

mesh. These aspects are required for this study so the models, on the surface,

are complete, and allow for accurate measurements to be taken. A future study

could include color correction and accuracy in the definition of research quality.

Research

Researchers using 3D models can remotely examine, analyze, and

measure objects and localities from around the world utilizing websites, apps,

augmented reality, virtual reality, and 3D printing (Freina and Ott, 2015; Akçayır

and Akçayır, 2017; Graham et al., 2017; Rodríguez-Gonzálvez et al., 2017;

Stepp, 2018; SketchFab, 2019).


14

An example for online access and viewing of 3D models is the website

and app SketchFab (SketchFab, 2019). SketchFab allows 3D model viewing and

customization of models regardless of browser or operating system (SketchFab,

2019). For example, annotations can be added to a model to guide viewers

during examination of an image. Within the SketchFab website (Figure 2.2),

models are viewable in 3D or virtual reality, and through SketchFab’s free app,

the models are also accessible in augmented reality. SketchFab also supports

sharing models across social media or embedding them on a website.

Figure 2.2. Casas Grandes Ramos Polychrome Effigy Jar (TTU-A10-53) viewed online in SketchFab.

Augmented reality (AR) virtually simulates having a 3D model in the

physical world. For example, a 3D model can be virtually “placed” on a table


15

allowing a user to see the model in the surrounding physical environment (Figure

2.3). AR was created in the 1960s and initially utilized bulky head-mounted

displays (Akçayır and Akçayır, 2017). Today, AR is accessible through personal

computers and mobile devices. Programs such as SketchFab allow for

an AR experience utilizing 3D models directly through a mobile app. Researchers

can utilize AR to walk around and view a model similarly to how they would view

it if the physical object was placed in front of them.

Figure 2.3. Casas Grandes Ramos Polychrome Effigy Jar (TTU-A10-53) viewed in Augmented Reality from a mobile device.

Virtual Reality (VR) places a user in a simulated world using 3D models of

pictures, objects, or environments. VR utilizes specific electronic equipment to

simulate experiences and interactions with the virtual in an ostensibly physical

way (Freina and Ott, 2015). VR can be experienced in either a non-immersive or

immersive environment. A non-immersive environment places a user in a virtual

environment through the use of a workstation containing a screen, keyboard, and


16

mouse. An immersive environment includes simulated projections surrounding a

user wearing 3D glasses (Figure 2.4; Freina and Ott, 2015).

Figure 2.4. Casas Grandes Mini Playas Red Footed Cup (TTU-A10-18) viewed in Virtual Reality through a mobile device utilizing Google Cardboard.

Models can also be downloaded from SketchFab for 3D printing. Before

printing, models can be imported into a Computer Aided Design (CAD) program

such as TinkerCAD to alter or add features to the model (Hurst et al., 2017;

Figure 2.5). Three-dimensional prints can enhance research by simulating

handling of the physical object.


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Figure 2.5. A Folsom projectile preform edited in TinkerCAD to include braille and three Ls indicating the Lubbock Lake Landmark logo (Hurst et al., 2017).

Museum Practices

In September 2018, a fire destroyed Brazil’s National Museum

(Thompson, 2018). This event did not just impact its immediate community:

the MoTTU and the Natural Science Research Laboratory, among others, lost

several specimens on loan to the institution (Personal Communication, B.

Mueller, 2018). Besides the loss of the museum itself, Thompson (2018) states

that another major loss is the loss of the physical objects. In natural science,

researchers may designate a new specimen as the holotype for a species,

however, the original specimen’s DNA data, field notes, and/or locational data

may be irreplaceable. In many cases, additional specimens do not exist,

especially in other fields such as anthropology or fine art. Therefore, 3D models,

in addition to 2D photographs and written documentation, can serve as records

that increase documentary control.


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Currently, professional standards for documentation of objects in catalog

records or condition reports recommend inclusion of a 2D photograph, however,

including a 2D rendering of a 3D object is not the best method of documentation.

The amount of information captured in a 3D representation of an object is

substantially greater than a 2D image: 3D models can rotate 360 degrees,

shape, size, and volume can be measured directly from the model, and cracks,

areas with missing fragments, and other damages can be easily shown and

measured directly from the model (Athanassopoulos and Shelton, 2015).

Built heritage can also use 3D representations as expanded

documentation. It has been exceptionally important in cases of a disaster. In April

2019, the Cathedral of Notre Dame, a cultural structure listed as a UNESCO

World Heritage site, experienced a structural fire during an on-going restoration

project (Captain, 2019). Luckily, laser scans of the structure were taken in 2015

by art historian, Andrew Tallon (Reyes, 2019). The results of his scans produced

a 3D rendering of the structure that can, in turn, produce engineering and

architectural drawings demonstrating how the building was constructed (Reyes,

2019).

Goals and Objectives

This research investigates how to create research-quality 3D models of

museum collection objects. The research question posed is: can 3D models fulfill

the analytical needs of researchers? A secondary research question is: are

measurements taken on virtual vessels more accurate than measurements taken

on a physical vessel? Sixty Casas Grandes vessels from the Division of


19

Anthropology at the Museum of Texas Tech University were 3D modeled and

shared with targeted researchers for analysis to determine the viability of

modeling a museum collection at a research quality level. Feedback from a

researcher survey provided data for addressing the research question. Further, a

measurement study to determine the accuracy and precision of taking

measurements on physical vessels versus virtual vessels was completed within

the MoTTU.

Goal 1: Utilize technology to expand research of a museum collection.

Objective 1: Provide a background on how museums use digital

heritage and 3D technologies.

Objective 2: Create 3D digital models of Casas Grandes pottery.

Objective 3: Conduct a survey of ceramic researchers, Casas

Grandes experts, and digital heritage specialists to evaluate the

use for research of virtual Casa Grandes vessels.

Objective 4: Examine the advantages and disadvantages of

photogrammetric 3D modeling for research of museum collection

objects.

Ending Comment

Museums can redefine their relationship with researchers by using 3D

modeling technology. The intersection of digital technology and heritage is the

philosophical framework used in this thesis to examine the viability of making

photogrammetric 3D models of museum collections for research.


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CHAPTER III

METHODOLOGY

Completing research Objectives 1-3 required the use of specific

techniques, technologies, and workflows. The methodologies used in this

thesis were developed from a combination of recommendations from select

digital heritage research projects and the standards and best practices for

management of digital images, and were refined during the project by trial-and-

error (Eerkens and Bettinger, 2001; Mudge et al., 2007). The methodologies

developed in this research add to a growing list of techniques to create and use

3D models.

Literature Review: Intersection of Museums and 3D Technology

The literature review fulfilling Objective 1 (Provide a background on how

museums are using digital heritage and 3D technology) focused on the

intersection of 3D technology with heritage as well as practices for integrating

this technology into museum contexts. Because of their direct relevance to this

thesis, publications relating to photogrammetric methods were reviewed

closely. Literature was gathered through Google Scholar, the Texas Tech Library

System, and organizations preserving heritage.

3D Modeling Process

To complete Objective 2 (Create 3D models of Casas Grandes pottery),

3D models of 60 vessels from the Fred Miles Casas Grandes ceramics

collection, cared for within the Division of Anthropology at the MoTTU, were

developed using Agisoft Metashape in the MoTTU’s digital lab. This digital lab


21

has two photogrammetry workstations, the photography equipment, and the

software required to make these models.

The metadata associated with each model was recorded in

photogrammetry logbooks. Each model’s metadata explains how the virtual

ceramic vessel was created, allows for the modeling process to be repeated, and

includes descriptions of equipment and software, camera settings, conversions,

edits, and corrections of errors (Mudge et al., 2007:3). The modeling methods

were automated, removing human choice and subjectivity, thus increasing the

possibility of replicating the process. After modeling all 60 vessels, the virtual

ceramic vessels were scaled based on two measurements taken from the

corresponding physical ceramic vessel and their dimensional accuracy was

checked.

The first step in the photogrammetry process captured overlapping digital

images with a Nikon D7200 camera equipped with a Nikon 28mm f/1.8G AF-S

NIKKOR lens. Camera exposures were controlled remotely using Smart Shooter

3 Version v3.33 software on a laptop to ensure the camera remained stable

through the imaging process. In general, a shutter speed of 1/1.6

and f13 aperture were used (Table 3.1). After photographing an object,

the unaltered digital images were converted from Nikon RAW to Adobe RAW

DNG using Adobe’s Digital Negative Converter. Adobe DNG is the only RAW

format compatible with MetaShape.


22

Table 3.1. Photography specifications used to capture photogrammetric images of the vessels in the Fred Miles Casas Grandes Collection.

Accession Number

Catalog Number

Form Design Shutter Speed

Aperture # of Chunks

Inside <

Bottom <

Side <

70-236 TTU-A10-3 Jar Plainware, Incised 1/1.6 13 6 3 0 3

70-196 TTU-A10-5 Jar Plainware, Incised 1/1.6 13 7 3 0 4

70-292 TTU-A10-6 Jar Playas Red Incised

1/1.6 13 11 6 0 5

70-279 TTU-A10-7 Jar Playas Red Incised

1/1.6 13 8 3 0 5

70-158 TTU-A10-10 Bowl Plainware, Textured, Scored

1 16 5 0 0 5

70-282 TTU-A10-12 Bowl Playas Red 1 16 5 0 0 5

70-167 TTU-A10-14 Bowl, Mini

Plainware 1/1.6 13 5 0 0 5


Plainware 1/1.6 13 5 0 0 5


Plainware 1/1.6 13 5 0 0 5

70-164 TTU-A10-18 Footed Cup

Playas Red 1/1.6 13 5 0 0 5

70-175 TTU-A10-20 Bowl Plainware 1 16 5 0 0 5

70-181 TTU-A10-21 Bowl Plainware 1/1.6 13 5 0 0 5


70-162 TTU-A10-23 Plate Plainware 1/1.6 13 5 0 0 5



23


Accession Number

Catalog Number



Inside <

Bottom <

Side <

70-268 TTU-A10-25 Bowl Babicora Polychrome

1/1.6 13 5 0 0 5

70-227 TTU-A10-26 Bowl Jar

Villa Ahumada or Babicora?

1/1.6 13 6 3 0 3

70-250 TTU-A10-27 Bowl Villa Ahumada Polychrome

1/1.6 13 5 0 0 5

70-240 TTU-A10-28 Bowl Villa Ahumada Polychrome

1/1.6 13 5 0 0 5

70-203 TTU-A10-29 Bowl Ramos Black 1/1.6 11 5 0 0 5


70-257 TTU-A10-31 Bowl Babicora Polychrome

1/1.6 13 5 0 0 5

70-260 TTU-A10-32 Bowl Ramos Polychrome

1/1.6 13 5 0 0 5

70-252 TTU-A10-33 Bowl Ramos Polychrome

1/1.6 13 5 0 0 5

70-276 TTU-A10-34 Effigy, F

Ramos Polychrome

1/1.6 13 8 2 0 6

70-277 TTU-A10-35 Effigy, M

Ramos Polychrome

1/1.6 13 7 3 0 4

70-256 TTU-A10-36 Jar Bowl

Ramos Polychrome

1/1.6 13 5 0 0 5

70-248 TTU-A10-38 Jar Babicora Polychrome

1/1.6 13 8 3 0 5

70-241 TTU-A10-39 2 neck Jar


1/1.6 13 5 0 0 5


24


Accession Number

Catalog Number



Inside <

Bottom <

Side <


70-167 TTU-A10-41 Bowl Playas Red 1/1.6 13 5 0 0 5



70-198 TTU-A10-44 Bowl Textured Plainware

1/1.6 13 5 0 0 5

70-281 TTU-A10-45 Bowl Playas Red 1/1.6 13 5 0 0 5

70-217 TTU-A10-46 Jar Playas Red 1/1.6 13 5 0 0 5

70-192 TTU-A10-47 Jar Plainware 1/1.6 13 6 3 0 3

70-258 TTU-A10-48 Effigy Jar

Babicora Polychrome

1/1.6 13 5 3 0 5




70-193 TTU-A10-52 Jar, Fluted

Plainware 1/1.6 13 8 3 0 5


Ramos Polychrome

1/1.6 13 8 3 0 5


Ramos Polychrome

1/1.6 13 8 3 0 5


70-233 TTU-A10-56 Jar Textured Plainware

1/1.6 13 6 3 0 3


25


Accession Number

Catalog Number



Inside <

Bottom <

Side <

70-278 TTU-A10-57 Bird Effigy

Playas Red 1/1.6 13 9 4 0 5


1/1.6 13 8 3 0 5

70-254 TTU-A10-59 Jar Corralitos Polychrome

1/1.6 13 7 2 0 5

70-189 TTU-A10-60 Jar Ramos Black 1/1.6 13 8 3 0 5


1/1.6 13 10 4 1 5

70-251 TTU-A10-63 Jar Dublan Polychrome

1/1.6 13 8 3 0 5

70-249 TTU-A10-64 Jar Villa Ahumada or Babicora?

1/1.6 13 8 3 0 5

70-246 TTU-A10-65 Jar Villa Ahumada Polychrome

1/1.6 13 8 3 0 5


1/1.6 13 10 3 2 5


70-214 TTU-A10-68 Jar, Mini

Ramos Black 1/1.6 13 6 1 0 5

70-242 TTU-A10-69 Jar Ramos Polychrome

1/1.6 13 8 3 0 5

70-244 TTU-A10-70 Jar Ramos Polychrome

1/1.6 13 5 0 0 5

70-261 TTU-A10-73 Jar Dublan Polychrome

1/1.6 13 10 4 1 5


26

The photography set-up included four desk lamps and a light tent to

evenly flood the object with light on all sides, a turntable with degree markers to

rotate the object, and archival foam cut-outs to support the object during imaging

(Figure 3.1). The camera was mounted on a tripod for stability.

Figure 3.1. Photography set-up with light tent, lamps, and camera mounted on a tripod.

Photogrammetry [Greek: phot (light) + gramma (something drawn) +

metrein (measure)] is the science of extracting three-dimensional data from 2D

images (Schenk, 2005: 3). Approximately 90-110 digital photographs taken from

five different angles were needed to record entirely each vessel (Figure 3.3). Jars

with steep rims often required three extra rotations focused directly on the inside


27

of the rim, resulting in 60 additional photographs, for a total of ~180

photographs.

Figure 3.2. A point cloud with data from overlapping images; the blue rectangles represent locations around the object from which each image was captured.


28

Figure 3.3. A Plainware Bowl (TTU-A10-22) rotated to five different angles to capture photographically a series of overlapping images of the entire vessel.

In the second step, the images were imported into Agisoft MetaShape as

one “chunk.” MetaShape defines a “chunk” as a group of digital images to which

the same alignment and processing functions are applied (Warnock et al., 2018).

Within a chunk, MetaShape automatically groups the five to eight angles into

separate sub-chunks (Figure 3.4).


29

Figure 3.4. Five sub-chunks containing 18 to 21 pictures each for a total of 96 images.

The computer used to run Agisoft MetaShape was an iMac desktop with a

3.4 GHz Intel Core i5 processor, 32 GB of RAM, and a Radeon Pro 570 4096 MB

graphics card running macOS Mojave Version 10.14. The monitor was set with

the default iMac color profile settings, version 2.1.0, found in display color under

system preferences. The version of Agisoft MetaShape used was Professional

Edition - 1.5.1 build 7618 (64 bit).

In the third step, a mask was added around the object (Porter et al., 2016;

Figure 3.5). Masks are needed when using a turntable so that the

photogrammetry software ignores the non-moving background, which might

otherwise cause image alignment errors. A mask was needed around each new

angle of the vessel as it was turned 360 degrees on the turntable resulting in six

to eight masks for each sub-chunk (Figure 3.6). A minimum of 30 to 40 masks

were required per vessel. Objects with more features or that were smaller in size

required more masks to exclude the background.


30

Figure 3.5. Using the Intelligent Scissors tool, the object was selected (left) and inverted (right) creating a mask around the object.

Figure 3.6. An example of the range of angles that required masks for each sub-chunk.

The fourth step was to align the images. In the alignment process,

matching points from overlapping pictures were found by MetaShape. If some

images failed to align (Figure 3.7), masks were added and the images were then


31

realigned. In five instances, some images were manually aligned by finding

common points among pictures that Metashape did not recognize.

Figure 3.7. An example of the images not aligning.

In the fifth step, a dense cloud of millions of locational data points with

associated pixel color information from the image was created. In

photogrammetry, the camera locations generated during the alignment step were

used to estimate depth information creating the dense cloud (Agisoft, 2019). The

dense cloud often included extra points from the background; these were deleted

manually (Figure 3.8).


32

Figure 3.8. The dense cloud with extra points from the background (left) and the dense cloud once the background has been excluded (right).

In the sixth step, individual points in the dense cloud were interpolated to

create an overlying mesh or surface consisting of thousands of interlocking

polygons (Agisoft, 2019). The larger the number of polygons used in this

process, the higher the model’s resolution. Each model averaged at least

700,000 polygons, with some of the more detailed models exceeding

1,000,000. If a void in the model was found as a result of an incomplete dense

cloud, additional photographs were taken and the model was reprocessed to add

the missing information.

In the seventh step, color information from the images was overlaid on top

of the mesh to create a textured surface for the model (Figure 3.9).


33

Figure 3.9. A sample of each of the four processes: 1) the point cloud generated from photo alignment; 2) the dense point cloud model estimating depths; 3) the polygonal model, or mesh, generated using the depths from the dense cloud; 4) the texture showing surficial details.

In the final step, each model was scaled to the physical object. Two non-

parallel linear measurements were taken using 0.1 mm accurate digital calipers

and recorded for each physical object. The same measured points were then

found on the virtual object. The measurements from the physical vessel were

added to the virtual vessel by dropping markers and defining the distance

between them. After the virtual model was scaled in two different directions using

the physical vessel’s measurements, measurement accuracy was confirmed by

measuring a third set of points and comparing the caliper’s measurement to the

measurement taken using the virtual ruler tool on the 3D model (Figure 3.10). If

the model’s measurement fell within 0.1 millimeters of the caliper’s

measurement, no rescaling was done. If the measurements differed by more


34

than 0.3 millimeters, the virtual model was rescaled until it was in concordance

with the physical ceramic vessel’s dimensions.

Figure 3.10. Measurement of the physical vessel (TTU-A10-60); Ramos Black Jar) using a caliper and measurement of the virtual vessel using the digital ruler tool. The measurements differed by 0.01 millimeter.


35

Measurement Study

A measurement study determined differences in accuracy and precision

between measuring the physical object and the virtual object. Five MoTTU

Heritage and Museum Sciences graduate student assistants were recruited to

collect measurements for comparison from the physical and virtual vessels.

These students had no prior experience with ceramic analysis or developing

virtual models. All the physical vessels were placed on tables, and the 60 virtual

vessels were accessed using two computers in the Digital Lab. Each student

measured independently the maximum and minimum rim diameters for each

physical and virtual vessel. Students used a cloth measuring tape, accurate to a

millimeter, to record physical measurements. Each virtual model was viewed and

measured without its texture to more accurately find the locations of the

maximum and minimum rim diameters. The physical and virtual measurements

were recorded on different sheets of paper in different rooms to prevent bias.

Results from this study compared the difference in measurement accuracy

and precision between the physical and virtual ceramic vessels. Accuracy

describes the similarity between a measurement and its true value (Lyman and

VanPool, 2009:487). Precision refers to the similarity of repeated measurements

of the same object (Lyman and VanPool, 2009:487).

Statistics used to compare accuracy and precision included mean,

standard deviation, coefficient of variation, and an ANOVA test. The mean, or

average, was calculated separately for maximum and minimum rim diameters,

and physical and virtual vessels. The standard deviation was used to determine


36

the spread of each person’s measurements for every vessel, both physical and

virtual. Standard deviation is the average variation in a set of values from their

mean. The lower the standard deviation, the closer the values are to the mean.

The higher the standard deviation, the higher the spread or variation is between

values. The coefficient of variation (CV), a ratio between the standard deviation

and the mean expressed as a percentage, compares the amount of variation.

The lower the CV, the more precise the measurement. A CV of 1.7% or less

indicates the measurements were precise, while CVs of 50% or greater indicate

no measurement precision (Eerkens and Bettinger, 2001). An ANOVA, or an

analysis of variance, was used to determine whether there were any significant

differences between the means of the focus group participants.

Humans commit errors in observation (Eerkens and Bettinger, 2001:494).

Every student in the study committed a blunder or caused a problem by a lack of

precision in measuring the vessels. This created incorrect data events (Lyman

and Vanpool, 2009:489). Measurement errors and blunders, however, are often

overlooked in large data sets (Odell, 1989). This measurement study aimed to

determine if there was a decrease in the number of errors or blunders committed

when measuring virtual objects by comparing the deviations in measurements of

the physical and virtual vessels.

Survey

Objective 3 (Conduct a survey to describe the potential use of the models

for research) was achieved through an online survey asking ceramic

researchers, Casas Grandes experts, and digital heritage specialists to review


37

the virtual models to determine their quality and potential usefulness to

researchers. Ceramic researchers, Casas Grandes experts, and digital heritage

specialists were all recruited in order to gather opinions from individuals with

varying levels of experience in ceramic study and 3D technology. Throughout the

discussion of the survey, ceramic researchers, Casas Grandes experts, and

digital heritage specialists will be referred to as researchers or respondents.

This online survey was conducted under Texas Tech University IRB2019-

982 (Appendix A). Survey questions used Smithsonian Institution and Audience

Research (SOAR) to determine organizational effectiveness (Smithsonian

Institution Archives, 2019), and implemented best practices and standards for

conducting museum visitor surveys as detailed by Hooper-Greenhill (2006). The

survey was uploaded online, using Microsoft Forms as a platform, and access to

the survey and to the MoTTU SketchFab site was shared with participants by

email (Appendix D).

The scaled virtual models were reviewed by the researchers on the

MoTTU’s SketchFab website (Figure 3.11). Each model was uploaded into the

Anthropology collection as a non-downloadable, publicly available model; each

model incorporated a background that included the Museum’s logo and a brief

description of the vessel in a caption. SketchFab is a web-based 3D platform that

provides tools for the public and scholars to view and interact with 3D models

(SketchFab, 2019).


38

Figure 3.11. A view of the Anthropology collection on SketchFab.

The target or focus group was formed by contacting 48 researchers by

email (Appendix B). Twenty-seven researchers participated in the study and

completed the survey, enough to receive diverse participation, but without an

overwhelming number of participants (Onwuegbuzie et al., 2009). Sampling error

was reduced by preventing a sample and response bias (Frechtling, 2002).

Prevention of a sample bias included a comparison of missing data with received

data (Frechtling, 2002). Prevention of a response bias focused on eliminating

leading, threatening, or unclear questions (Frechtling, 2002). The survey was

anonymous and did not collect any data identifying individuals by name, gender,

age, or related information.


39

The survey consisted of 11 questions: three questions determined the

background of the respondents, one question determined a respondent’s

familiarity with these virtual models, three questions determined the quality of the

experience each respondent had with these models, and four questions

determined how these models could or could not be used for research.

Question 1 aimed to determine the professional circumstance or situation

of each respondent. For this study, it was essential to include professionals from

ceramic analysis and digital heritage to determine if these models, 1) can be

studied like their physical counterparts, and 2) are high-quality. Other non-

professional positions such as “graduate student” were included in the event that

the survey was shared outside of the target group and to identify those

anomalies. Respondents could select more than one category.

Question 1: Describe the professional position(s) that you currently hold: (select

as many as apply)

o Undergraduate Student

o Graduate Student

o Faculty

o Researcher

o Archaeology Professional

o Museum Professional

o Heritage Management Professional

o Retired

o Other


40

Question 2 aimed to determine each respondent’s experience with

ceramics. This was important in determining how the virtual vessel models could

or could not be used for ceramic research in the future. If a respondent had 5+

years of experience studying ceramics, it was assumed they had a higher

working knowledge of the techniques required to study ceramics and, therefore,

their responses to questions 8, 9, 10, and 11 were potentially more informed.

Question 2: How long have you studied ceramics?

o Never

o 0-1 year

o 2-5 years

o 5-10 years

o 10+ years

Question 3 aimed to determine how, and if, each respondent had

interacted with 3D technologies, and specifically virtual models, prior to this

study. This question was important to determine the level of experience each

respondent had with 3D models. If a respondent had previously used a 3D model

for research or created a 3D model, it could be assumed they had a higher

working knowledge of 3D imaging and modeling techniques, and thus have a

more informed perspective than someone with no prior experience with 3D

models.

Question 3: Prior to this study, have you: (select all that apply)

o Viewed 3D models on social media or on a website

o Used Augmented Reality (AR)


41

o Used Virtual Reality (VR)

o Used 3D models for research

o Printed 3D models

o Created a 3D model

o Never used a 3D model

o Other

Question 4 aimed to determine the level of interaction each respondent

had with the Fred Miles Casas Grandes collection on SketchFab. Each

respondent was asked to view at least five models so they did not form their

opinions based solely on a single or few models.

Question 4: How many of the Casas Grandes 3D models did you view on

SketchFab?

o 6-10

o 11-15

o 16-20

o 21-25

o 25+

Question 5 aimed to determine the quality of the resolution of the models.

Resolution includes the ability to zoom, quality of the texture, and clarity and

sharpness of the edges.

Question 5: While reviewing the Casas Grandes ceramic models, in your opinion,

model resolution was

o Low quality


42

o Medium quality

o High quality (useful for research)

o Other

Question 6 aimed to determine the quality of colors in the models.

Question 6: While reviewing the Casas Grandes 3D models, in your opinion, the

models’ colors were

o Low quality

o Medium quality

o High quality (useful for research)

o Other

Question 7 aimed to determine each respondent’s overall satisfaction with

the 3D models.

Question 7: Please rank the overall quality of the 3D models for potential

research:

o Below expectations

o Meets expectations

o Above expectations

Question 8 aimed to determine how the models of ceramic vessels could

be used in research. The goal was to determine how ceramic analytical

techniques could be completed using the models. Measurements, a measuring

tool, and a color target were not provided in this part of the study.

Question 8: In what ways could these Casas Grandes models be used in ceramic

research? (select as many as apply)


43

o Determining ceramic construction methods

o Identifying temper/paste/slips or other materials

o Determining firing techniques

o Classifying vessels

o Accurately measuring vessels

o For type classification

o Analysis of decoration techniques

o Analysis of design elements

o Determining the function of the vessel

o Other

Question 9 was an open-ended question aimed at asking respondents to

provide feedback about the potential limitations of the 3D models. A list of

limitations was not provided to prevent influencing a respondent’s opinion.

Question 9: In what ways do 3D models of ceramics not fulfill analytical research

needs?

Question 10 was an open-ended question aimed at asking the

respondents to provide feedback about potential benefits to using 3D models for

research. A list of benefits was not provided to prevent influencing a respondent’s

opinion.

Question 10: Can these models of ceramics be used in analyses that advance

research beyond traditional ceramic analytical techniques?

Question 11 aimed to determine in what ways 3D models could be

used for research.


44

Question 11: Which of the following would be of interest for future research

utilizing 3D models? (select as many as apply)

o Recording measurements

o Color analysis

o GIS analysis

o 3D printing

o Augmented Reality (AR)

o Virtual Reality (VR)

o Other

Advantages and Disadvantages of 3D Modeling

Objective 4 (examine the advantages and disadvantages of

photogrammetric 3D modeling for research of museum collection objects) was

achieved through evaluating and synthesizing results from Objective 3 and the

measurement study. The efficacy of use was determined through an evaluation

given to the researchers that asked them to rate their experience using the virtual

models. The accuracy of the models was assessed through the measurement

study and a statistical analysis. Based on the results of the surveys and

measurement study, the viability of this approach for making research quality

models was assessed. Further, the advantages and disadvantages of using 3D

models for research were examined.

Concluding Remarks

This study required the use of different techniques and technologies to

complete each research objective. The techniques used in this study were


45

developed through trial-and-error to construct research quality 3D models.

Through a literature review, a background of understanding in the intersection of

technology and heritage was established. This allowed for the creation of best

practices for this study that also follow the MoTTU’s collection management

policies and procedures. Sixty photogrammetric models of Casas Grandes

ceramics were created and shared on SketchFab. An in-house measurement

study was completed to determine the variability between measurements taken

on physical versus virtual vessels. A survey was shared with researchers to

determine if they could utilize the virtual vessels for research, and, if so, how

effective the models were. Utilizing the results from the measurement study and

the survey, the advantages and disadvantages of using 3D models of museum

collection objects for research were discovered.


46

CHAPTER IV

RESULTS

This study used and examined quantitative and qualitative data

(Berkowitz, 1997). Quantitative data, or data that lend themselves to

mathematical calculations, were utilized in analyzing both the measurement

study and the user survey (Surendran, 2020). Qualitative data, or data that

approximate or characterize information in a non-numerical method, were utilized

in analyzing a portion of the survey results (Surendran, 2020).

Measurement Study Analysis

Common measurements used in the analysis of whole vessel ceramics

are maximum and minimum rim diameter (Orton, 1982; Verdan, 2011). Five

MoTTU Heritage and Museum Science students recorded both maximum and

minimum rim measurements for each of the 60 physical vessels and their

corresponding virtual vessels. A total of 1,200 measurements were logged in a

spreadsheet for analysis (Appendix D & E).

A one-way analysis was conducted to compare the accuracy of

measurements between the physical and virtual vessels (Figures 4.1 and 4.2).

First, the maximum rim diameter measurements were examined. Persons 1, 2,

and 4 had, on average, positive differences indicating that they obtained larger

measurements on the physical vessels. In contrast, Persons 3 and 5 recorded

larger measurements on the virtual vessels than their physical counterparts,

resulting in a negative difference. Persons 1, 4, and 5 had less than a two-

millimeter average difference (Table 4.1; Figure 4.1). Person 3 was the least


47

accurate with a difference of -7.26 mm. Person 3 also had the most significant

outliers and a large standard deviation of 24.58 mm.

Table 4.1. Mean of the differences (Physical – Virtual Maximum Rim) and standard deviation for each person’s maximum rim diameter measurements.

Mean Standard Deviation

Person 1 1.12 3.43

Person 2 2.74 3.1

Person 3 -7.26 24.58

Person 4 1.54 8.18

Person 5 -0.12 7.22


48

Figure 4.1. One-way analysis of maximum rim diameter measurements (Physical – Virtual Maximum Rim) by person.

The accuracy of measuring the minimum rim dimension was higher than

the maximum rim dimension (Table 4.2, Figure 4.2). Persons 1, 2, and 5 had less

than a two-millimeter variance between the physical and virtual vessels, and

Person 4 was slightly above with a variance of 2.15 mm. Person 3 was the least

accurate with a mean variance of -5.96 due to significant outliers. In contrast to


49

measuring the maximum rim diameter, the participants were more likely to obtain

a larger measurement on the virtual vessel than its physical vessel counterpart.

Table 4.2. Mean of the differences (Physical – Virtual Minimum Rim) and standard deviation for each person’s minimum rim diameter measurements.

Mean Standard Deviation

Person 1 -1.57 4.24

Person 2 -0.61 5.5

Person 3 -5.96 31.62

Person 4 2.15 8.27

Person 5 0.48 11.2

Figure 4.2. One-way analysis of minimum rim diameter measurements (Physical - Virtual Minimum Rim) by person.


50

An analysis of variance (ANOVA) indicates Person 3’s accuracy level was

significantly different from the other four participant’s maximum rim diameter

measurements (Table 4.3) and significantly different to Persons 4 and 5’s

minimum diameter measurements (Table 4.4). When compared, Persons 1, 2, 4,

and 5 did not have significant variance among their measurements and,

therefore, their levels of accuracy were not significantly different (Table 4.4).

Table 4.3. Maximum rim diameter coefficient of variation p-values for each person.

Table 4.4. Minimum rim diameter coefficient of variation p-values for each person.

The degree of precision of measuring the physical versus the virtual

vessels was next examined. Precision was examined by comparing the

coefficient of variation (CV) of participants measurements for each physical and


51

virtual vessel (Figure 4.3; Table 4.5). Lower CVs indicate less variation, and thus,

more precise measurements.

Figure 4.3. One-way analysis comparing the coefficient of variation for each measurement type. Table 4.5. The mean and standard deviation of all measurements for each measurement type.

CV Mean CV Standard Deviation

Physical Maximum 5.62 5.88

Physical Minimum 7.5 6.5

Virtual Maximum 3.73 3.93

Virtual Minimum 4.65 3.93


52

Both the maximum and minimum rim measurements on the physical

vessels show a larger deviation compared to the virtual vessel measurements

(Figure 4.3; Table 4.5). An ANOVA (Table 4.6) demonstrates that the level of

precision of measuring the physical minimum rim diameter and virtual maximum

rim diameter were highly statistically different (p-value 0.0029). The level of

precision was slightly statistically different for measuring the physical maximum

rim diameter and virtual maximum rim diameter (p-value 0.468), and physical

minimum rim diameter and physical maximum rim diameter (p-value 0.0483). In

contrast, there was not a significant statistical difference in the level of precision

between measuring the physical maximum rim diameter and the virtual minimum

rim diameter (p-value 0.3052), or the virtual minimum rim diameter and the virtual

maximum rim diameter (p-value 0.3327). For both the physical and the virtual

vessels, the minimum rim diameter measurements had more variation and less

precision than, the maximum rim diameter measurements. This suggests that the

participants of this study were less precise in measuring the minimum rim

diameter compared to the maximum rim diameter.

Table 4.6. Coefficient of variation p-values for each measurement type.


53

Survey Analysis

The survey (Table 4.7) was sent to 48 researchers: 27 Casas Grandes or

ceramic experts and 21 digital heritage specialists. They were also asked to

share the survey with anyone who may have an interest in this study. A total

of 27 individuals anonymously completed the survey.

Table 4.7. List of questions from the researcher survey.

Question 1 Describe the professional position(s) that you currently hold:

(select as many as apply)

Undergraduate student/Graduate

student/Faculty/Researcher/Archaeology

Professional/Museum Professional/Heritage Management

Professional/Retired/Other

Question 2 How long have you studied ceramics?

Never/0-1 year/2-5 years/5-10 years/10+ years

Question 3 Prior to this study, have you: (select all that apply)

Viewed 3D models on social media or on a website/Used

Augmented Reality (AR)/Used Virtual Reality (VR)/Used 3D

models for research/Printed 3D models/Created 3D

models/Never used a 3D model/Other

Question 4 How many of the Casas Grande 3D models did you view on

SketchFab?

6-10/11-15/16-20//21-25/25+

Question 5 While reviewing the Casas Grande ceramic models, in your

opinion, model resolution was…

Low quality/Medium quality/High quality (useful for

research)/Other


54


Question 6 While reviewing the Casas Grande ceramic models, in your

opinion, the models’ colors were…

Low quality/Medium quality/High quality (useful for

research)/Other

Question 7 Please rank the overall quality of the 3D models for potential

research:

Below expectations/Meets expectations/Above expectations

Question 8 In what ways could these Casas Grandes models be used in

ceramic research? (select as many as apply)

Determining construction methods/Identifying

tempter/paste/materials/Documenting firing

techniques/Measuring and classifying vessel shape/Obtain

caliper-quality measurements/For type classification/Analysis

of decoration techniques/Analysis of design

elements/Determining the function of the vessel/Other

Question 9 In what ways do these 3D models of ceramics not fulfill

analytical research needs?

Short Answer

Question 10

Can these 3D models of ceramics be used in analyses that

advance research beyond traditional ceramic analytical

techniques?

Short Answer

Question 11 Which of the following would be of interest for future research

utilizing 3D models? (select as many as apply)

Recording measurements/Color analysis/GIS analysis/3D

printing/Augmented Reality (AR)/Virtual Reality (VR)/Other

Each participant was asked a series of background questions to determine

their professional positions, knowledge of ceramics, and prior experience with 3D


55

models (Appendix F). For the questions concerning professional position and

prior experience with 3D technology, participants could select more than one

answer. Most of the respondents (n=15) held a faculty position at a university, but

there was a spread amongst the other descriptors: Archaeology Professional

(n=9), Researcher (n=7), Retired (n=5), Museum Professional (n=4), and

Heritage Management Professional (n=2)(Figure 4.4). Four respondents were

graduate students. Over 70 percent of respondents (n=18) had at least five years

of experience studying ceramics, with most respondents (n=16) having ten or

more years of experience studying ceramics (Figure 4.5). Six respondents had

less than two years of experience studying ceramics. Two participants did not

respond to this question, however, they had previous experience as faculty

members and as archeology professionals.

Figure 4.4. Background of survey participants.

15

9

7

54 4

21

0

2

4

6

8

10

12

14

16

Respondents' Backgrounds


56

Figure 4.5. Length of time each respondent had previously studied ceramics.

Of the 27 participants, 24 had used some form of 3D technology or 3D

model before this study; three participants had never used 3D technologies or 3D

models before (Figure 4.6). The most common method of accessing 3D models

was through a social media website (n=24; Figure 4.6). Eleven participants (41%)

had created a 3D model prior to this study. Overall, most respondents have prior

experience studying ceramics and interacting with 3D models. The survey,

therefore, successfully identified a knowledgeable target group of researchers.

The two respondents with no prior experience in archeology or in analyzing

ceramics were omitted from the analysis.

2

4

1

216

Length of Time Studying Ceramics

Never 0-1 year 2-5 years 5-10 years 10+ years


57

Figure 4.6. Survey participants’ prior experience with 3D modeling.

The survey asked researchers to review the 3D models on SketchFab.

Thirty-six of the 60 models were uploaded and available for viewing. Only 36

models were uploaded due to the restricted number of free uploads permitted by

SketchFab. Most respondents (n=18, 72%) viewed 6-10 of the models (Figure

4.7). One respondent wrote that they could not open the models in their browser.

This individual’s responses have been omitted from the analysis, reducing the

sample size to 24.

24

910

9

5

11

3

0

8

15

23

30

Viewed 3Dmodels on

Social Media

UsedAugmentedReality (AR)

Used VirtualReality (VR)

Used 3Dmodels forresearch

Printed 3Dmodels

Created a 3Dmodel

Never used a3D model

Prior 3D Technology Experience


58

Figure 4.7. Number of models each respondent viewed during this study.

Researchers were asked three questions focused on model resolution,

model color, and overall quality of the models. Most respondents (n=16, 67%)

reported that the models were high resolution and useful for research (Figure

4.8). Eight respondents (33%) reported that the models were of a medium

quality. No one rated the models as having a low-quality resolution. Most

respondents (n=16, 67%) observed that the model’s colors were high quality

and useful for research (Figure 4.9). Six respondents (23%) reported that the

model colors were medium quality. No one rated the model colors as low quality.

Two respondents selected “other” and stated it was difficult to answer the

question without target colors. Most respondents (n=16, 67%) noted that the

overall quality of the 3D models for potential research met expectations (Figure

4.10). All other respondents (n=8, 33%) reported that the overall quality of the 3D

models for potential research was above expectations. No one rated the overall

quality of the 3D models for potential research below expectations.

18

2

1

2

2

Number of Models Viewed

6-10 models 11-15 models 16-20 models 21-25 models 25+ models


59

Figure 4.8. Respondents’ rating for model resolution.

Figure 4.9. Respondents’ rating for model color.

0

8

16

Model Resolution

Low Quality Medium Quality High Quality

0

6

16

2

Color Quality

Low Quality Medium Quality High Quality Other


60

Figure 4.10. Respondents’ ratings for overall quality.

Based on their experience using these 3D models, respondents were

asked how the models could potentially be used in ceramic research (Figure

4.11). Respondents were able to select more than one answer. All participants

(n=24, 100%) found the models to be useful for analyzing design elements on the

vessels. Most participants also found the models to be useful for analyzing

decoration techniques (n=22, 92%), determining type classification (n=21, 88%),

classifying vessels (n=17, 71%), and determining the function of the vessel

(n=13, 54%). Fewer respondents found the models to be useful for accurately

measuring vessels (n=7, 29%), determining ceramic construction techniques

(n=5, 21%), determining firing techniques (n=4, 17%), or identifying

temper/paste/slip (n=1, 4%).

0

16

8

Overall Quality

Below expectations Meets expectations Above expectations


61

Figure 4.11. Respondents’ opinions on how these 3D models could be used for research.

Respondents were asked to describe how the models do not fulfill their

analytical research needs. Respondents wrote their responses rather than

selecting pre-determined answers. This question was optional and 23 of the

survey participants responded. Common words and phrases were recorded and

tallied. Half (n=12, 50%) of the respondents voiced wanting to measure the

models but were not sure how, or if SketchFab allowed for this feature. Seven

respondents (29%) stated they were not sure if they could study texture, paste,

or temper with the models, but mentioned that this is not always possible with a

physical vessel without destructive analysis. Difficulty studying weight was

mentioned once. Three respondents (13%) asked for a photo color chart to be

included. Several respondents mentioned limitations of SketchFab (n=4, 17%), a

5

1

4

17

7

2122

24

13

0

5

10

15

20

25

30

Potential Uses for Research


62

lack of inclusion of metadata on SketchFab (n=3, 13%), and a poor zoom feature

on SketchFab (n=5, 21%).

Respondents also wrote responses demonstrating their opinions on the

affordances gained from 3D models. This was optional and 23 (96%) of the

survey participants responded to this question. Common words and phrases

were recorded and tallied. Respondents (n=12, 50%) commonly noticed the 3D

models could be used for more invasive studies in the place of the physical

vessel and the models eliminated the need for costly travel for researchers or the

objects. Two respondents noticed a benefit of the models in cases of repatriated

objects. Seven respondents suggested that the models allowed for a greater

potential for access, outreach, and interaction. Many respondents listed other

uses for the 3D models in research: volumetric studies (n=3, 13%), comparative

analysis (n=3, 13%), geometric morphometric analysis (n=3), interior viewing

(n=2), and iconographical study (n=1, 4%). One respondent (4%) was unsure but

noted that the current models could potentially be used to further research if they

included a dimensional scale and a color chart. Three respondents (13%) were

unsure and two respondents (8%) did not think the virtual models could be used

in any type of new analysis beyond what can be studied with the physical

vessels.

Finally, respondents were asked their future interest in using 3D

technologies for research. Respondents could select more than one answer.

Most responses highlighted the ability to record measurements (n=18, 75%),

possibilities of 3D printing (n=16, 67%), color analysis (n=15, 63%), Augmented


63

Reality (n=11, 46%), and Virtual Reality (n=11, 46%). There was little interest

among researchers (n=6, 25%) using GIS to study the models.

Figure 4.12. Areas in which respondents were interested in using models in future studies.

In further analysis of the survey, two questions were considered based on

questions developed by the National Science Foundation (NSF); (Berkowitz,

1997):

1. What patterns or common themes are present in the data?

2. Are there deviations from these patterns? Can these deviations be

explained?

An important difference within the target group is if the respondent had

prior experience creating 3D models or not. Responses from respondents with

experience creating 3D models were compared to responses from respondents

with no prior experience creating a 3D model for model resolution, model color,

and overall quality. Ten respondents (42%) stated they had created a 3D model

prior to this study. Fourteen respondents (58%) have not previously created a 3D

18

15

6

16

11 11

0

2

4

6

8

10

12

14

16

18

20

Recordingmeasurements

Color analysis GIS analysis 3D printing AugmentedReality (AR)

Virtual Reality(VR)

3D Technology Interests


64

model and three of those respondents (13%) had never experienced any 3D

technology such as AR, VR, or 3D prints prior to this study.

Respondents with 3D modeling experience more often rated the model

resolution as high quality and useful for research (n=7, 70%) compared to

respondents with no 3D modeling experience (n=9, 64%; Figure 4.14).

Figure 4.13. Responses from respondents with prior 3D modeling experience (left) vs. respondents with no prior 3D modeling experience (right) for model resolution. Respondents with 3D modeling experience more often rated the color

quality as high quality and useful for research (70%) compared to respondents

with no 3D modeling experience (n=9, 64%; Figure 4.14). Two respondents with

no prior 3D experience selected “Other.” Respondent 12 wrote, “very hard to tell

but likely useful for research.”

0

3

7

Model Resolution with 3D Experience


0

5

9

Model Resolution with no 3D Experience



65

Figure 4.14. Responses from respondents with prior 3D modeling experience (left) vs. respondents with no prior 3D modeling experience (right) for model color. Respondents with no 3D modeling experience selected that the model’s

overall quality was above their expectations (n=6, 43%) more frequently than

respondents with 3D modeling experience (n=2, 20%; Figure 4.15). Eight

respondents with no 3D modeling experience (57%) selected that the overall

quality of the models met their expectations and eight respondents with 3D

modeling experience (80%) selected that the overall quality of the models met

their expectations. This difference could be attributed to those with 3D

experience understanding current 3D modeling technology and the quality that is

expected. No respondents selected that the overall quality of the models was

below their expectations.

0

3

7

Color Quality with 3D Experience


0

3

9

2

Color Quality with no 3D Experience

Low Quality Medium Quality

High Quality Other


66

Figure 4.15. Responses from respondents with prior 3D modeling experience (left) vs. respondents with no prior 3D modeling experience (right) for overall model quality.

There was only one deviation from the pattern of the respondents. One

individual expressed they could not open the models in their browser. As stated

previously, their responses were eliminated from survey results because this

individual did not interact with the models, and thus did not provide an accurate

rating for the quality of the models.

0

8

2

Overall Quality with 3D Experience

Below Expectations Meets Expectations

Above Expectations

0

8

6

Overal Quality with no 3D Experience

Below Expectations Meets Expectations

Above Expectations


67

CHAPTER V

DISCUSSION

Museums are increasingly expanding their methods of managing and

interpreting their collections through the use of 3D technologies and specifically

3D modeling (Müller, 2002:22; Athanassopoulos and Shelton, 2015; He et al.,

2017:342). Objects can be individually modeled for analysis and measurement

and full collections can be digitally documented, curated, and studied (Graham et

al., 2017). Additionally, 3D models allow for digital preservation and protection of

objects, collections, structures, and cultural heritage sites (Thompson, 2018;

Reyes, 2019).

This research demonstrates the viability of using 3D models of museum

collection objects for research. Both the measurement study and the researcher

survey deliver a proof-of-concept of using 3D models of museum collection

objects for research and how an institution can implement photogrammetric

models in-house and share their models, and thus their collections, with others.

Measurement Study

The measurement study aimed to determine if there was a difference in

the accuracy and precision of measuring a physical or virtual vessel. Results

indicate a high level of accuracy between measurements taken on a physical

vessel when compared to measurements taken on its respective virtual vessel.

An examination of the coefficient of variation (CV) comparing participant

measurements demonstrates more variation, and thus less precision, measuring

the physical vessels. The lower amount of variation, or more precision,


68

measuring virtual vessels suggests a virtual analysis may provide more reliable

results.

A disparity in some of the measurements were noted among the five

individuals who measured the vessels. Each individual who participated

committed a blunder, or an error, decreasing their precision in measuring. For

some vessels, there was a significant variation between each individual’s

measurements of the maximum and minimum rim diameters. These

measurement differences between individuals may suggest that their

inexperience in working with ceramics and 3D models caused measurement

errors. Within anthropology, measurements such as “maximum” and “minimum”

often have different meanings to different researchers. Personal bias may enter

into a study as seemingly unbiased as creating measurements. Further,

discrepancies in interpretation of the instructions and potentially in previous

schooling or training can influence an individual’s technique (Fish, 1978:88).

Variation will be present in any measurement process regardless of the object

being measured. This study demonstrates less variation, and thus, increased

precision in measurements, when measuring the virtual vessels, even with the

preexisting biases, discrepancies in the interpretation of instructions, and random

errors (Eerkins and Bettinger, 2001).

Based on observations during the research, measuring maximum and

minimum rim diameters is easier to do virtually due to the affordances of

manipulating a virtual vessel on a computer. For example, the maximum and

minimum rim diameter were more apparent on a 2D computer screen, especially


69

with no texture involved. On the physical vessels, the place to measure the

maximum and minimum rim diameters may not have been as apparent due to

the colors and textures of the vessels. Participants may have also been able to

more easily rotate on the computer screen the virtual vessels to precisely find the

dimensions instead of being more hesitant in manipulating the physical ceramic

vessel for fear of damage. Future work is needed to explore these possibilities.

Survey

The survey aimed to determine researchers’ opinions and interests in

using 3D models for research. Twenty-seven researchers anonymously

completed the survey after interacting with the virtual vessels. The respondents

answered questions to determine previous experience with 3D technology,

ceramics, their opinions on the 3D vessels of the Fred Miles Casas Grandes

collection, and their interests in using 3D technologies for research in the future.

The 27 respondents were narrowed down to 24 to create a survey population

consisting of only researchers with previous ceramic experience. Most of these

researchers had experience working with 3D models, and 10 (42%) had created

3D models previously. The survey was successful in creating a focus group

consisting of participants with experience in ceramic analysis, and also having

knowledge of 3D modeling.

The following responses demonstrate how the respondents perceived the

models to be helpful in the preservation of an original object:

Having indigenous representatives view these models instead of transporting them through potentially hazardous conditions to ascertain their origin or production would be fantastic. (Respondent 6)


70

…it certainly does allow researchers to add more to their samples without traveling. It also keeps any additional use-wear from occurring. (Respondent 12)

This is a great method for preservation and access to pots that won't damage them. Also, it's great for items that may be repatriated. (Respondent 15)

A respondent suggested that interactions and outreach are increased

with 3D models of museum objects:

From a museum and public archaeology perspective, the use of 3D images, and hopefully of physical 3D printing should give us new outlets for interactive displays, for holding and handling without worry about items being either stolen or damaged, and for selling miniature or full size replicas to visitors as a means of reinforcing that actual artifacts should never be sold. Sticking strictly to a research realm, and with the ability to easily document measurements, 3D images could make many collections accessible to researchers by eliminating the enormous cost of travel for graduate students, and possibly even ways of bringing collections into elementary or middle school classrooms, etc. to conduct much needed public outreach. (Respondent 22)

Another respondent noted their study of geometric morphometrics, or the

virtual study of shape using coordinates, demonstrates more reliable

measurements than other techniques:

The data demonstrate[s] ceramic measurements capture[d] with geometric morphometrics are more reliably recorded with less error between individuals and in repeated sessions with the same analyst. Similar methods could be used with these high-quality models. (Respondent 21) Several respondents noted that some of the same drawbacks to using

these 3D models for research are also issues while studying the physical

vessels:

…there are some fine grained and destructive techniques that are important, but not possible with models… (Respondent 7)

It would be hard to assess paste characteristics from the models, but this is also true of whole vessels without broken edges. (Respondent 8)


71

You definitely can't identify characteristics of paste and temper, which is not surprising as a binocular microscope is required to do that anyway. (Respondent 22)

It is noted that destructive techniques are not possible with the 3D models. A 3D

model could, however, be created prior to a destructive analysis to preserve the

original form while also allowing for the invasive study to be conducted. Other

limitations, such as vessel weight, were noted, but this information, could be

shared by request.

Responses from respondents with prior experience creating 3D models

were compared to responses from respondents with no experience creating a 3D

model for model resolution, model color, and overall quality. Ten respondents

(42%) stated they had created a 3D model prior to this study. Fourteen

respondents (58%) have not previously created a 3D model and three of these

respondents (13%) had never experienced any 3D technologies prior to this

study. Respondents with 3D experience (n=7, 70%) more highly rated the model

resolution than respondents with no 3D experience (n=9, 64%). Respondents

with 3D experience (n=7, 70%) also more highly rated the color quality for the

models than respondents with no 3D experience (n=9, 64%). Respondents with

no 3D experience (n=6, 43%) ranked the models’ overall quality above their

expectations at a higher percentage than respondents with 3D experience (n=2,

20%). Respondents with 3D modeling experience may be more familiar with

current quality standards of 3D models, and more frequently thought the models

met current expectations. No respondents selected that the overall quality of the

models was below expectations.


72

Benefits and Limitations of the Methodology

The modeling workflow using photogrammetry (Appendix C) and physical

measuring is repeatable on other ceramic vessels at other institutions and

collections other than ceramics. However, this workflow took several months of

repeated trial and error to determine the optimum numbers of photos, angles for

photos, and workflow settings. Slight modifications may be needed to optimize

the workflow for other collections.

The in-house measurement study aimed to determine the variability

between measurements taken on physical vessels and virtual vessels. The study

was successful in demonstrating less variation between measurements taken

using virtual vessels. A future study should examine if there is a difference in the

accuracy and precision of measurements obtained by experienced ceramic

analysts and 3D modeling professionals. Results from that work may determine if

the amount of experience would lead to more precise measurements of the

physical vessels compared to virtual counterparts.

The survey aimed to determine if 3D models could be used for research,

gauge the interest in using 3D models for research, and how researchers could

use 3D models. The original design of the study included survey respondents

participating in a measurement aspect of the models. However, there is currently

no software that allows for the simple sharing of accurately scaled 3D models for

taking measurements. Scaled models can be shared with other researchers, but

it requires additional knowledge of 3D modeling and the appropriate software. It


73

was not assumed in this survey that respondents had this knowledge and

appropriate software for measuring virtual ceramics. A color chart and monitor

settings would be provided in a future study to provide a measure of the accuracy

of colors.

Significance of Results

Most respondents rated the model resolution (n=16, 67%) and color

(n=16, 67%) as high quality and useful for research. All of the respondents

thought the ceramic 3D models met or exceeded their expectations for use in

research. The measurement study demonstrated that taking measurements on

the virtual vessels can be as accurate and maybe more repeatable than

measuring the physical vessels. Future work is needed to test and explore the

implication of these results.


74

CHAPTER VI

CONCLUSION

This research aimed to evaluate the reception of 3D photogrammetric

models created from a museum collection of Casas Grandes ceramic vessels.

Following the creation of the models, a measurement study was conducted to

compare the accuracy and precision of measuring the physical vessels versus

their virtual counterparts. Then through a survey that included ceramic

researchers, Casas Grandes experts, and digital heritage specialists, the virtual

vessels’ potential for use in research was assessed. A mixed-methods approach

of quantitative and qualitative data was used to analyze both the measurement

study and the researcher survey results. A philosophical perspective based upon

digital heritage and 3D technology’s intersection with and role in museums

shaped the framework for this research.

The measurement study demonstrated less variation in measurements

taken on virtual vessels than measurements taken on physical vessels. The

survey demonstrated that the models met and exceeded most respondent’s

expectations for research quality models. No respondents stated that the models

did not meet their expectations. Further, the respondents expressed interest in

the possibilities of using 3D models in their research. Both the measurement

study and the researcher survey deliver a proof-of-concept of using 3D models

for research.


75

Concluding Remarks

Through the creation and sharing of 3D models for a measurement study

and target/focus group survey, this research demonstrates the feasibility of 3D

modeling museum collections using photogrammetry for researchers. Results of

this research demonstrate that in many cases 3D models can be used by

researchers in analysis. These results add to the developing field of digital

heritage and increase access to a museum collection for research.


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Porter, Samantha Thi, Morgan Roussel, and Marie Soressi 2016 A Simple Photogrammetry Rig for the Reliable Creation of 3D Artifact Models in the Field: Lithic Examples from the Early Upper Paleolithic Sequence of Les Cottés (France). Advances in Archaeological Practice, 4(1): 71-86. Quimby, Meredith L., Katherine W. L. Vig, Robert G. Rashid, Allen R. Firestone 2004 The Accuracy and Reliability of Measurements Made on Computer-Based Digital Models. Angle Orthodontist, 74(3): 298-303. Reyes, Kris 2019 Previously Captured 3D Images Will Be Used to Restore Notre Dame Cathedral After Fire. Retrieved from: https://abc7news.com/3d-images-to-be-used-for-notre-dame-cathedral-reconstruction/5256599/ Rodríguez-Gonzálvez P., M. Rodríguez-Martí, Luís F. Ramos, and D. González-Aguilera 2017 3D Reconstruction Methods and Quality Assessment for Visual Inspection of Welds. Automation in Construction, 79: 49-58. Sanmartín, Patricia, Elisabet Chorro, Daniel Vázquez-Nion, Francisco Miguel Martínez-Verdú, and Beatriz Prieto 2014 Conversion of a Digital Camera into a Non-Contact Colorimeter for Use in Stone Cultural Heritage: The Application Case to Spanish Granites. Measurement, 56: 194-202. Schenk, T. 2005 Introduction to Photogrammetry. GS400.2 Autumn Quarter:3 Retrieved from: http://www.mat.uc.pt/~gil/downloads/IntroPhoto.pdf Serain, Clément 2018 The Sensitive Perception of Cultural Heritage’s Materiality Through Digital Technologies. Studies in Digital Heritage, 2(1): 54-66. SketchFab 2019 Publish and Find 3D models Online. Retrieved from: https://sketchfab.com/ Smithsonian Institution Archives 2019 Electronic Records Program History. Retrieved from: https://siarchives.si.edu/what-we-do/digital-curation/electronic-records-program

https://abc7news.com/3d-images-to-be-used-for-notre-dame-cathedral-reconstruction/5256599/

https://abc7news.com/3d-images-to-be-used-for-notre-dame-cathedral-reconstruction/5256599/

http://www.mat.uc.pt/~gil/downloads/IntroPhoto.pdf

https://sketchfab.com/

https://siarchives.si.edu/what-we-do/digital-curation/electronic-records-program


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SmugMug 2014 The Art of Copy Work: Photographing Artwork Accurately Without Glare. Retrieved from: https://news.smugmug.com/the-art-of-copy-work-photographing-artwork-accurately-without-glare-80208e717304 Stepp, Jessica 2018 The Viability of 3D Technologies to Increase Access to Museum Collections. Master’s Thesis, Texas Tech University, Lubbock. Strategic Plan 2016-2020 2016 Strategic Plan 2016-2020. Retrieved from: https://www.depts.ttu.edu/museumttu/about/StratPlan.pdf Surendran, Anup 2020 Qualitative Data- Definition, Types, Analysis and Examples. QuestionPro Inc. Retrieved from: https://www.questionpro.com/blog/qualitative-data/ Thompson, Helen 2018 Before it Burned, Brazil’s National Museum Gave Much to Science. ScienceNews. Retrieved from: https://www.sciencenews.org/article/brazil-national-museum-collections-scientific-contributions United Nations Educational, Scientific and Cultural Organization (UNESCO) 2003 Charter on the Preservation of the Digital Heritage. Retrieved from: http://www.unesco.org/new/fileadmin/MULTIMEDIA/HQ/CI/CI/pdf/mow/charter_preservation_digital_heritage_en.pdf. 2019 Concept of Digital Heritage. Retrieved from: https://en.unesco.org/themes/information-preservation/digital-heritage/concept-digital-heritage VanPool, Christine S., and Todd L. VanPool 2007 Signs of the Casas Grandes Shamans. University of Utah Press, Salt Lake City. Verdan, Samuel 2011 Pottery Quantification: Some Guidelines. Early Iron Age Pottery: A Quantitative Approach, Proceedings of the Internaional Round Table organized by the Swiss School of Archaeology in Greece (Athens, Noember 28-30, 2008), Archaeopress 2011: 165-171.

https://news.smugmug.com/the-art-of-copy-work-photographing-artwork-accurately-without-glare-80208e717304

https://news.smugmug.com/the-art-of-copy-work-photographing-artwork-accurately-without-glare-80208e717304

https://www.depts.ttu.edu/museumttu/about/StratPlan.pdf

https://www.questionpro.com/blog/qualitative-data/

https://www.questionpro.com/blog/qualitative-data/

https://www.sciencenews.org/article/brazil-national-museum-collections-scientific-contributions

https://www.sciencenews.org/article/brazil-national-museum-collections-scientific-contributions

http://www.unesco.org/new/fileadmin/MULTIMEDIA/HQ/CI/CI/pdf/mow/charter_preservation_digital_heritage_en.pdf

http://www.unesco.org/new/fileadmin/MULTIMEDIA/HQ/CI/CI/pdf/mow/charter_preservation_digital_heritage_en.pdf

https://en.unesco.org/themes/information-preservation/digital-heritage/concept-digital-heritage

https://en.unesco.org/themes/information-preservation/digital-heritage/concept-digital-heritage


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Warnock, Jonathan P., Joseph E. Peterson, Steven R. Clawson, Neffra A. Matthews, and Brent H. Breithaupt 2018 Close-range Photogrammetry of the Cleveland-Lloyd Dinosaur Quarry, Upper Jurassic Morrison Formation, Emery County, Utah. Geology of the Intermountain West, 5: 271-285. Whalen, Michael E. and Paul E. Minnis 2001 Casas Grandes and its Hinterland: Prehistoric Regional Organization in Northwest Mexico. University of Arizona Press, Tucson. Wilson, C. Dean 2014 Tradition Name: Casas Grandes. Office of Archaeological Studies: Pottery Typology Project. Retrieved from: http://ceramics.nmarchaeology.org/typology/tradition?p=19 Yeats, V. L. 1970 Letter to Mrs. Fred A. Miles sent from Lubbock, May 6, 1970, Fred Miles Collection. Copy on file at the Museum of Texas Tech University, Anthropology Division, Lubbock.

http://ceramics.nmarchaeology.org/typology/tradition?p=19


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APPENDIX A

IRB APPROVAL LETTER

Oct 22, 2019 10:39 AM CDT Stance Hurst Museum Re: IRB2019-982 3D Modeling Museum Collection Objects Findings: Good luck with your research! Dear Dr. Stance Hurst, Peter Briggs, Richard White, Megan Ostrenga: The Human Research Protection Program determined that your project meets at least one of the federal exempt categories under 45 CFR 46: Category 2.(i). Research that only includes interactions involving educational tests (cognitive, diagnostic, aptitude, achievement), survey procedures, interview procedures, or observation of public behavior (including visual or auditory recording). The information obtained is recorded by the investigator in such a manner that the identity of the human subjects cannot readily be ascertained, directly or through identifiers linked to the subjects. The determination was made on October 22, 2019. Annual review is not required, and no expiration date will be listed on your letter. The research must follow Texas Tech University’s Operating Procedures, the Belmont Report, and 45 CFR 46. If changes to the approved protocol occur, a Modification Submission must be reviewed and approved by the IRB before implementation. Please contact the Human Research Protection Program to determine if a modification is needed or submit a Modification Submission in Cayuse IRB. Please be aware that changes to the research protocol may prevent the research from qualifying for exempt review and require submission of a new IRB application or other materials to the Texas Tech University IRB. A goal of the IRB is to prevent negative occurrences during any research study. However, despite our best intent, unforeseen circumstances or events may arise during the research. If a deviation, unanticipated problem or adverse event


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happens during your research, please notify the Texas Tech University, Human Research Protection Program as soon as possible (45 CFR 46). We will ask for a complete explanation of the event and for you to submit an Incident Submission in Cayuse IRB. Your study may be selected for a Post-Approval Monitoring (PAM). You will be notified if your study has been chosen for a PAM. A PAM investigator may request to observe your data collection procedures, including the consent process. Once your research is complete, please use a Closure Submission to archive this study. IRBs that remain active are subject to audit by the IRB. Sincerely, Original signature available upon request Kelly Cukrowicz, Ph.D. Chair Texas Tech University Institutional Review Board Professor, Department of Psychological Sciences Human Research Protection Program 357 Administration Building Lubbock, Texas 79409-1075 T 806.742.2064 www.hrpp.ttu.edu

http://www.hrpp.ttu.edu/


84

APPENDIX B

CASAS GRANDES CERAMICS DESCRIPTIONS

Name Texture Colors Design Picture

Plainware May include incisions, tool punches, or scoring

Plain surface, interior is brown and unslipped

N/A


85

APPENDIX B CONTINUED


Playas Red May include Playas Red Incised variety

Covered in a red slip, banded

Incisions may include horizontal chevrons, horizontal bands, parallel lines, or small punctuations

Babicora Polychrome

N/A Light brown or gray paste; Designs include red and black pigment

Thick opposing patterns of triangles or scrolls in one or two bands around the vessel


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N/A Undecorated portions are buff to tan; Designs are in deep red or orange and black

Bands are framed into panels; triangles with interlocking scrolls, step triangles, and bent lines are inside bands.

Ramos Black

May include Ramos Black Incised variety

Black surface, may also have a red paste

Unusual vessel forms


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Ramos Polychrome

N/A White to light gray paste, black and red design elements

Fine line work; bold triangles or step triangles with thin outlines, geometric motifs, checkerboard patterns; may include animal forms


Incised lines and patterns on upper portion

Brown in color, lower portion may be covered in a red slip, red or black painted motifs around the incised lines

Painted and incised linear designs on upper portion


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Dublan Polychrome

Corrugated neck

Dull ivory to tan, red and black designs

Polychrome extends over the corrugated neck


89

APPENDIX C

PHOTOGRAMMETRY WORKFLOW

Adding pictures:

• Open a New Project in Agisoft MetaShape

• Workflow, Add Folder, Select and Open, Single Camera, Add Chunks into 1 Folder with Separate Sub-Chunks

Masking:

• Select image to mask

• Intelligent Scissors, hold Command, trace and click edges of object in image

o Shift, Command, I (invert mask), Shift, Command, A (add mask) Align Photos:

• Workflow, Batch Process, Align Photos o All chunks, Accuracy: High, Generic Preselection: Yes, Reference

Preselection: No, Key Point Limit: 80,000, Tie Point Limit: 0, Apply Masks To: Key Points, Adaptive Camera Model Fitting: No

Build Dense Cloud:

• Change Bounding Box to fit all points (resize)

• Workflow, Batch Process, Build Dense Cloud o Quality: High, Depth Filtering: Aggressive, Reuse Depth Maps: No,

Calculate Point Colors: Yes

• Remove extra background data points if needed Build Mesh:

• Workflow, Batch Process, Build Mesh o Source Data: Dense Cloud, Surface Type: Arbitrary, Depth Maps

Quality: High, Face Count: Medium Build Texture:

• Workflow, Batch Process, Build Texture o Mapping Mode: Generic, Texture From: All Cameras, Blending

Mode: Average (or Mosaic), Hole Filling: No, Enable Ghost Filling: No

Scaling:

• Right click two distinctive markings on the model to drop markers

• Reference, right click the two markers needing scaling, Create Scale Bar, manually add measurements in millimeters

• Repeat creating two perpendicular measurements

• Click the ruler tool to update the model with the measurements


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APPENDIX D

MAXIMUM RIM DIAMETER MEASUREMENTS FOR PHYSICAL AND VIRTUAL VESSELS

PERSON 1 MAX (mm)

PERSON 2 MAX (mm)

PERSON 3 MAX (mm)

PERSON 4 MAX (mm)

PERSON 5 MAX (mm)

Catalog # P V P V P V P V P V

A10-03 87 84.4 89 84.9 75 81.5 87 85.2 84 82

A10-05 94 95.2 95 92 85 78.5 94 91.4 90 90

A10-06 72 68.3 73 68.5 64 57.5 71 73.8 68 66

A10-07 123 121 128 122 112 118 125 123 120 117

A10-10 132 132 137 121 123 125 135 128 91 130

A10-12 170 173 170 171 166 167 174 170 171 170

A10-14 50 52.1 55 50.8 47 49.3 49 49.8 50 55

A10-15 48 48.5 52 47.4 45 44.8 52 48 47 48

A10-17 72 73.3 74 74 79 70 75 73.2 73 74

A10-18 89 88.8 91 89.3 80 87.2 90 89.3 90 87

A10-20 112 112 112 110 104 103 111 112 111 110

A10-21 184 177 184 177 174 171 182 174 178 173

A10-22 147 145 147 144 140 141 148 142 144 143

A10-23 156 149 157 152 148 149 155 152 154 150

A10-24 136 134 138 133 128 130 135 134 134 133

A10-25 94 92.9 95 92.5 90 91.5 95 93.6 94 92

A10-26 96 95 91 96 85 89.6 91 91.1 89 89

A10-27 142 142 144 143 133 137 140 142 134 142


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APPENDIX D CONTINUED

PERSON 1 MAX (mm)

PERSON 2 MAX (mm)

PERSON 3 MAX (mm)

PERSON 4 MAX (mm)

PERSON 5 MAX (mm)


A10-28 135 132 134 135 127 132 133 133 131 131

A10-29 237 252 240 253 129 241 240 252 233 241

A10-30 159 157 160 157 45 152 160 156 158 153

A10-31 193 192 195 195 183 188 194 192 193 188

A10-32 123 120 125 123 122 124 125 124 123 123

A10-33 138 138 140 138 134 143 140 139 135 136

A10-34 111 115 119 113 111 119 110 110 110 110

A10-35 126 123 125 124 120 118 124 122 120 121

A10-36 81 84.4 84 80.2 75 73 85 83.5 78 78

A10-38 112 113 113 111 117 110 110 111 110 111

A10-39 122 119 121 118 120 119 116 118 115

A10-40 122 119 122 118 115 120 123 122 118 122

A10-41 177 173 180 177 164 160 179 173 177 172

A10-42 101 99.7 105 101 98 98 100 101 102 104

A10-43 117 114 116 113 114 107 116 114 114 113

A10-44 79 78.3 88 78.4 71 74 82 79.8 76 84

A10-45 217 215 219 216 205 209 219 214 210 211

A10-46 129 127 130 127 121 120 127 131 124 120

A10-47 100 98.5 102 99.8 82 91.7 112 106 100 95

A10-48 121 119 124 117 105 113 123 118 115 119

A10-49 80 78.2 79 76.8 65 74.6 76 77.5 75 76


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APPENDIX D CONTINUED

PERSON 1 MAX (mm)

PERSON 2 MAX (mm)

PERSON 3 MAX (mm)

PERSON 4 MAX (mm)

PERSON 5 MAX (mm)


A10-50 117 128 117 112 105 108 115 125 114 112

A10-51 119 118 120 118 119 115 115 113 117 114

A10-52 123 120 125 120 104 110 123 126 123 119

A10-53 114 111 110 111 106 107 114 110 112 107

A10-54 114 111 115 114 105 106 112 112 111 109

A10-55 79 78.8 80 78.3 71 74.5 81 87 77 91

A10-56 83 80.5 84 79.9 72 71.8 83 79.9 80 77

A10-57 113 111 115 111 105 105 113 113 124 110

A10-58 127 124 128 123 135 123 123 128 125 123

A10-59 106 102 105 101 100 93.5 103 101 101 98

A10-60 101 99.6 101 99 97 94.5 101 103 95 103

A10-62 126 121 137 137 110 185 110 124 125 134

A10-63 107 106 106 105 100 98.7 107 110 109 102

A10-64 102 99.3 100 97.8 93 97.1 103 102 100 98

A10-65 103 103 104 103 90 92 101 101 100 113

A10-66 113 112 115 111 102 97 113 112 110 108

A10-67 123 118 124 121 115 113 125 122 123 120

A10-68 26 26.8 31 26.9 24 25.5 23 24.9 20 24

A10-69 96 93.5 97 93.2 88 88.3 91 92.9 91 91

A10-70 128 127 130 126 118 203 181 126 130 121

A10-73 146 142 148 143 135 137 166 157 150 138


93

APPENDIX E

MINIMUM RIM DIAMETER MEASUREMENTS FOR PHYSICAL AND VIRTUAL VESSELS

PERSON 1 MIN (mm)

PERSON 2 MIN (mm)

PERSON 3 MIN (mm)

PERSON 4 MIN (mm)

PERSON 5 MIN (mm)


A10-03 86 83.9 70 75.5 75 73.2 84 83.2 80 81

A10-05 89 88.7 84 70.2 83 74.7 94 91.3 87 88

A10-06 69 67.2 54 51.4 60 57.3 69 67.4 63 61

A10-07 122 120 100 107 110 111 122 120 113 116

A10-10 126 124 120 119 119 74.8 120 125 90 123

A10-12 172 171 165 165 165 166 174 170 169 168

A10-14 47 47.8 47 45.7 42 45.9 49 48.8 49 49

A10-15 49 46.8 44 43.1 44 43.5 50 47.5 45 46

A10-17 74 71 68 66.6 75 67.6 74 72.7 70 72

A10-18 88 86.6 87 82.8 80 83.7 90 87.7 89 85

A10-20 109 105 99 104 98 99.9 110 106 108 108

A10-21 178 174 176 167 172 167 180 173 113 170

A10-22 144 142 139 136 137 140 145 140 143 141

A10-23 148 147 148 148 147 145 153 147 149 148

A10-24 131 132 128 128 127 129 136 132 131 129

A10-25 89 90.4 90 88.7 89 90.4 93 92.2 91 90

A10-26 87 86.3 85 83.2 83 83.8 90 89.6 91 84


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APPENDIX E CONTINUED

PERSON 1 MIN (mm)

PERSON 2 MIN (mm)

PERSON 3 MIN (mm)

PERSON 4 MIN (mm)

PERSON 5 MIN (mm)


A10-27 132 138 132 134 132 136 137 141 134 138

A10-28 127 132 126 128 126 131 133 132 130 130

A10-29 229 243 220 234 122 238 230 242 228 238

A10-30 147 155 140 138 45 149 158 155 155 252

A10-31 184 188 182 191 181 187 190 187 189 185

A10-32 118 119 114 117 119 119 122 120 119 116

A10-33 131 136 131 132 130 134 140 136 121 133

A10-34 104 109 107 104 110 112 100 104 109 108

A10-35 117 122 114 113 95 91.3 120 119 115 117

A10-36 79 78.1 70 73.1 75 71.8 84 78.9 76 75

A10-38 106 109 96 105 114 108 109 111 108 105

A10-39 67.5 55 54.6 67 68 73.5 108 66

A10-40 114 118 114 115 112 116 118 119 117 117

A10-41 167 170 152 151 161 157 174 171 174 163

A10-42 94 97.6 92 96.3 90 95.2 100 100 100 99

A10-43 109 114 108 106 110 106 116 112 109 122

A10-44 79 75.9 70 74.4 68 72.8 78 75.8 75 76

A10-45 155 152 141 141 143 145 159 153 160 150

A10-46 126 123 110 117 117 115 125 126 122 119

A10-47 98 96.2 90 90.5 92 89.5 112 103 98 94

A10-48 112 113 118 107 90 110 120 117 112 112

A10-49 75 73.5 57 69.8 64 69.1 74 73.5 73 73


95

APPENDIX E CONTINUED

PERSON 1 MIN (mm)

PERSON 2 MIN (mm)

PERSON 3 MIN (mm)

PERSON 4 MIN (mm)

PERSON 5 MIN (mm)


A10-50 111 109 90 102 102 104 112 110 110 105

A10-51 113 112 101 103 112 107 115 112 108 112

A10-52 120 119 104 106 103 110 122 119 120 115

A10-53 107 108 106 103 105 104 114 109 110 104

A10-54 108 107 102 101 105 96.4 110 110 109 104

A10-55 77 78.5 59 70.6 70 74.3 77 77.8 75 73

A10-56 82 77.8 65 72.5 70 68.1 80 77 79 76

A10-57 94 97.1 90 87.2 88 92.2 110 100 99 96

A10-58 123 129 107 107 135 111 125 123 123 119

A10-59 95 97.8 91 93.2 95 91.6 103 101 100 96

A10-60 92 98.7 96 93 95 91.6 100 100 93 94

A10-62 116 119 113 112 179 95 124 100 114

A10-63 98 104 97 95.2 95 97.5 105 103 106 101

A10-64 93 98.3 95 91.8 92 91.6 101 98.8 99 94

A10-65 90 101 92 91.4 87 91 101 100 95 96

A10-66 109 108 93 94.4 102 94.9 110 109 104 103

A10-67 120 120 101 99.9 115 110 125 120 122 117

A10-68 23 23.8 23 21.4 22 22.5 21 24.3 24 23

A10-69 91 91.7 94 83.3 85 86.6 95 90.9 89 89

A10-70 116 120 106 112 114 113 170 120 125 120

A10-73 136 152 138 130 130 134 166 156 149 136


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APPENDIX F

BACKGROUND OF SURVEY RESPONDENTS

Professional Positions Years of Experience with Ceramics

Previous 3D Technology Experience

Graduate Student; 0-1 year Used Augmented Reality (AR); Used Virtual Reality (VR);

Graduate Student; 0-1 year Viewed 3D models on social media or on a website; Used Augmented Reality (AR); Used Virtual Reality (VR); Created a 3D model;

Graduate Student; 0-1 year Viewed 3D models on social media or on a website; Used 3D models for research; Created a 3D model;

Graduate Student; 0-1 year Viewed 3D models on social media or on a website; Used Augmented Reality (AR); Used Virtual Reality (VR);

Faculty; 5-10 years Viewed 3D models on social media or on a website; Used Virtual Reality (VR); Used 3D models for research; Created a 3D model;


97

APPENDIX F CONTINUED



Faculty; Researcher; Archaeology Professional;

10+ years Viewed 3D models on social media or on a website;

Faculty; Researcher; Heritage Management Professional;

Never Managed a 3D imaging and research program; Viewed 3D models on social media or on a website; Used Augmented Reality (AR); Used Virtual Reality (VR); Used 3D models for research;

Faculty; 10+ years Viewed 3D models on social media or on a website;

Faculty; Researcher; 10+ years Viewed 3D models on social media or on a website;

Faculty; 5-10 years Never used a 3D model;

Faculty; 10+ years Viewed 3D models on social media or on a website; Used Augmented Reality (AR); Used Virtual Reality (VR); Used 3D models for research; Printed 3D models; Created a 3D model;


98




Faculty; Archaeology Professional; Museum Professional; Retired;

10+ years Viewed 3D models on social media or on a website; Printed 3D models; Created a 3D model;

Archaeology Professional; Museum Professional;

10+ years Viewed 3D models on social media or on a website; Used 3D models for research; Created a 3D model;

Retired; 10+ years Never used a 3D model;

Faculty; Researcher; 10+ years Viewed 3D models on social media or on a website; Used Augmented Reality (AR); Used Virtual Reality (VR); Created a 3D model;

Retired; 10+ years Viewed 3D models on social media or on a website;

Faculty; Never Viewed 3D models on social media or on a website; Printed 3D models;

Faculty; 10+ years Viewed 3D models on social media or on a website; Used 3D models for research; Created a 3D model;


99




Archaeology Professional;

2-5 years Viewed 3D models on social media or on a website;

Archaeology Professional; Museum Professional;


Archaeology Professional; Retired;


Faculty; Researcher; Archaeology Professional; Museum Professional; Heritage Management Professional;

10+ years Viewed 3D models on social media or on a website; Used Augmented Reality (AR); Used Virtual Reality (VR); Used 3D models for research; Printed 3D models; Created a 3D model;

Faculty; Retired; 10+ years Never used a 3D model;

Faculty; 10+ years Viewed 3D models on social media or on a website; Used Augmented Reality (AR); Used Virtual Reality (VR); Used 3D models for research; Created a 3D model;


100




Researcher; Archaeology Professional;

Viewed 3D models on social media or on a website; Used 3D models for research;

Faculty; Researcher; Archaeology Professional;


Educator; Never Viewed 3D models on social media or on a website; Used Augmented Reality (AR); Used Virtual Reality (VR); Printed 3D models; Created a 3D model;


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APPENDIX G

EMAIL TO RESEARCHERS/IRB STATEMENT

Hello , My name is Megan Ostrenga and I am a Masters Candidate at Texas Tech University completing a thesis examining whether 3D models can be used for research when the original object is not easily accessible. For this study, Southwest Casas Grandes ceramic vessels were 3D modeled at the Museum of Texas Tech University using photogrammetry. The 3D models are viewable on the SketchFab website (https://sketchfab.com/MoTTU-heritage-lab/collections/mottu-anthropology) We ask that you review the quality of the 3D models for potential research. Following your review, please complete an 11-question survey about your experience examining the models (https://forms.office.com/Pages/ResponsePage.aspx?id=v1GKFyCL_0m2VVYkXVwXPDqFBm_2_HNMtZZ1t6b5KTBUMlRYQkxITEpWMVo4QllTODNCUENQRDVQRy4u) Participation is completely voluntary, and there are no direct benefits for your participation. This study should take less than 15 minutes to complete, and you can stop at any point and skip any questions you prefer not to answer. There are no foreseeable risks to your participation. To protect your confidentiality, no names will be collected. This study is being conducted under Texas Tech University IRB2019-982 in fulfillment of a master's thesis for the Master of Arts in Heritage and Museum Sciences. Please feel free to forward this survey to anyone else who may be interested in this study. We greatly appreciate your time and effort. Megan Ostrenga Masters Candidate Heritage and Museum Sciences Museum of Texas Tech University [email protected] Stance Hurst, PhD Graduate Faculty

https://sketchfab.com/MoTTU-heritage-lab/collections/mottu-anthropology

https://forms.office.com/Pages/ResponsePage.aspx?id=v1GKFyCL_0m2VVYkXVwXPDqFBm_2_HNMtZZ1t6b5KTBUMlRYQkxITEpWMVo4QllTODNCUENQRDVQRy4u



mailto:[email protected]


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Heritage and Museum Sciences Museum of Texas Tech University [email protected]

mailto:[email protected]

in heritage and museum sciences

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