Kotaro Yamafune

In the past seven years, photogrammetry has become one of the main recording methods in maritime and underwater archaeology. The application of photogrammetry allows archaeologists to recreate underwater cultural heritage sites in 3D digital formats, and extract from these 3D digital models data and information required for subsequent scholarly research. The author has been using photogrammetry since 2014 and has successfully created nearly 40 underwater cultural heritage models on more than 10 archaeological projects. The projects have ranged in size, accessibility, and water clarity, introducing a number of variables to the photogrammetry of the artifacts. The variety of experiences gained on these projects have enabled the author to construct his own methodology and workflow for photogrammetric recording. In this paper, the author shares examples of his methodology and workflow for photogrammetric recording of various projects in different countries.

Namban screens, a well-known Japanese art form, were painted by skillful Japanese artists from the late 16th century to the 17th centuries. Approximately 90 of these screens have been handed down up to the present. Not only they show some important historical scenes of European commercial activities in the Far East for the first time, but they also depict representational pictures of Portuguese ships during the Age of Discovery. Although the ships’ images on the screens are roughly acceptable, the details are often strangely anachronistic. The same images could be found in some Western maps in the 16th century. Judging from the similarity, perhaps, Japanese painters, who had never seen actual ships themselves in ports, did manage to copy the images from ones on those maps, which were brought to Japan by the wellknownTensho embassy. This was the first Japanese embassy that was sent to Europe; the diplomats left Japan in 1582 and arrived at Portugal in 1584. They met with Pope Gregory XIII and his successor, Pope Sixtus V, in Rome, and then returned back to their homeland in 1590. In the following year the embassy members succeeded in seeing HideyoshiToyotomi, who was the leading political ruler in Japan at that time. They gave him some souvenirs from Europe, including the maps. It seems that some official court painters had a chance to see those gifts, from where Japanese artists could have obtained an idea of the ships’ images that appear in the Namban screens.

Agisoft PhotoScan and other off-the-shelf photogrammetry software became available for archaeologists in 2010; In 2017, after only 7 years, photogrammetry has become a one of the most frequently used recording methods for UCH (underwater cultural heritage) sites. The author of this paper works as a professional maritime archaeologist and applied photogrammetric recording on more than 35 archaeological sites in more than 10 different countries. Because of its submerged circumstances of many shipwrecks, each site has different conditions: such as visibility and colors of waters, depth, topography, water current and so on. Those different conditions create problems that requires different ways to solve those difficulties. Additionally, each project has different mission statement, or project’s goal. For that reason, each submerged site requires different types of methodologies for data-collection and data processing. Moreover, to use produced 3D digital models as archaeological data, it is important to create 1:1 scale-constrained georeferenced 3D models (Yamafune et al., 2016). Yet, to produce these accurate models, it is essential to takes a week to produce local coordinate system that gives scale and georeferenced on the model. To solve these lengthy problem, the author created a methodology that produces local coordinate system in short time (1 or 2 dives) yet provide fairly accurate results. In this paper, the author shall share his methodology of photogrammetric recording that he has developed and currently using.

To use 3-D photogrammetric models as scientific data, it is essential for archaeologists to use local coordinate systems to constrain their photogrammetric models to 1:1 scale. This enables archaeologists to take measurements directly from their models. Direct Survey Methods (DSM) are often used to create local coordinate systems; however, DSM often requires several days of diving operations, which may become problematic when recording large or deep-water sites.
As a quick alternative method, the authors propose “Tri-Closure.” This method uses only three control points, placed to form an isosceles triangle. The coordinates of the control points can be calculated using the Pythagorean Theorem. After the initial photogrammetric recording, coordinates of any points within the enclosed area are automatically established. Tri-Closure is advantageous for photogrammetric recording because it requires only one or two diving operations to set up. In this paper, the authors will explain the step-by-step process of the proposed method.

Since the ancient time, people built watercrafts to across ocean. At the end of the 15th century, development of technology allowed European to across Atlantic and Indian Oceans. This technological advancement triggered the Age of European Expansion. The main actors of this phenomena was Spanish and Portuguese, or Iberians. Today, thanks to both historical and archaeological evidences, archaeologists can reconstruct appearances of Iberian ships of this era using computer aided 3-D drawing and modeling software. In this paper, the author explains his reconstruction of the Iberian ships based on both archaeological and historical evidences.

In June 2015, Texas A&M University, the Institute of Nautical Archaeology and the Lake Champlain Maritime Museum hosted a field school at Shelburne Bay, Lake Champlain. Along with manual recording by archaeologists, the team applied photogrammetric recording to Wreck 2 (Agisoft PhotoScan). The goal of this recording was to create an accurate 1/1 scale constrained model to use as archaeological data. However, low visibility of the water (2-5 ft.) and the sheer size of the wreck (135 ft. 6 in. in length) created difficult conditions to apply photogrammetry. This talk will share various hints on how we successfully created an accurate 1:1-scale constrained photogrammetric model of Wreck 2 at the Shelburne site, despite these adverse conditions.

Namban screens, a well-known Japanese art form, were painted by skillful Japanese artists from the late 16th century to the 17th centuries.  Approximately 90 of these screens have been handed down up to the present.  Not only they show some important historical scenes of European commercial activities in the Far East for the first time, but they also depict representational pictures of Portuguese ships during the Age of Discovery.  Although the ships’ images on the screens are roughly acceptable, the details are often strangely anachronistic.  The same images could be found in some Western maps in the 16th century.  Judging from the similarity, perhaps, Japanese painters, who had never seen actual ships themselves in ports, did manage to copy the images from ones on those maps, which were brought to Japan by the well known Tensho embassy.  This was the first Japanese embassy that was sent to Europe; the diplomats left Japan in 1582 and arrived at Portugal in 1584. They met with Pope Gregory XIII and his successor, Pope Sixtus V, in Rome, and then returned back to their homeland in 1590.  In the following year the embassy members succeeded in seeing Hideyoshi Toyotomi, who was the leading political ruler in Japan at that time.  They gave him some souvenirs from Europe, including the maps.  It seems that some official court painters had a chance to see those gifts, from where Japanese artists could have obtained an idea of the ships’ images that appear in the Namban Screens.

In 2010, a new off-the-shelf software for Computer Vision Photogrammetry, Agisoft PhotoScan, became available to nautical archeologists, and this technology has since become a popular method for recording underwater shipwreck sites. Today (2015), there are still active discussions regarding the accuracy and usage of Computer Vision Photogrammetry in the discipline of nautical archaeology. The author believes that creating a 1:1 scale constrained photogrammetric model of a submerged shipwreck site is not difficult as long as archaeologists first establish a local coordinate system of the site.  After creation of a 1:1 scale constrained photogrammetric model, any measurements of the site can be obtained from the created 3D model and its digital data. This means that archaeologists never need to revisit the archaeological site to take additional measurements. Thus, Computer Vision Photogrammetry can substantially reduce archaeologists’ working time in water, and maximize quantity and quality of the data acquired.
Furthermore, the author believes that the acquired photogrammetric data can be utilized in traditional ship reconstruction and other general studies of shipwrecks. With this idea, the author composed a new methodology that fuses Computer Vision Photogrammetry and other digital tools into traditional research methods of nautical archaeology. Using this method, archaeologists can create 3D models that accurately represent submerged cultural heritage sites, and these can be used as representative archaeological data. These types of representative data include (but are not limited to) site plans, technical artifact or timber drawings, shipwreck section profiles, georeferenced archaeological information databases, site-monitoring systems, digital hull fragment models and many other types of usable and practical 3D models. In this dissertation, the author explains his methodology and related new ideas.

This PowerPoint Presentation was prepared for Kotaro Yamafune's public presentation at his doctoral dissertation defense (December 17th, 2015).

He is currently preparing series of articles based on this doctoral research.

If you are interested in reading his unpublished manuscript of this dissertation, please feel free to contact,

koutarou_yamafune_0321@yahoo.co.jp

Namban screens are a well-known Japanese art form that was produced between the end of the 16th century and throughout the 17th century. More than 90 of these screens survive today. They possess substantial historical value because they display scenes of the first European activities in Japan. Among the subjects depicted on Namban screens, some of the most intriguing are ships: the European ships of the Age of Discovery.
              Namban screens were created by skillful Japanese traditional painters who had the utmost respect for detail, and yet the European ships they depicted are often anachronistic and strangely. On maps of the Age of Discovery, the author discovered representations of ships that are remarkably similar to the ships represented on the Namban screens. Considering the hypothesis that ships of some of the Namban screens are copies of ships represented on contemporary European cartography, the author realized that one particular historical event connecting Europe and Japan may be the source of these representations. This was the first visit of the Japanese Christian embassy, the Tensho Embassy, to Rome, in 1582. Its journey to Europe and its following visit to the Taiko, or first effective leader of Japan, Hideyoshi Toyotomi, may have been a trigger for the production of one of the most well-known Japanese artworks, the Namban screens.

In June 2015, Texas A&M University hosted a field project at Shelburne Bay, Lake Champlain. This field season focused on Wreck 2, a steamboat most likely from the 1830s. After its retirement, the steamer was sunk intentionally to provide a wooding dock for the working steamboats (as evidenced by mountains of stones). The site at Shelburne Bay, occupying an area only 100m by 150m, contains three steamers all built in the 1830s. These excellent archaeological examples provide us with a concentrated look into the early development of steamboat construction in North America’s inland waterways.

Along with manual recording by archaeologists, the team applied photogrammetric recording to Wreck 2 (Agisoft PhotoScan) under 50cm to 1.5m visibilities of water. The goal of this recording was to create an accurate 1:1 scale-constrained model to use as archaeological data. To create a 1:1 scale-constrained model, the team applied Direct Survey Methods (3H Site Recorder) and collected 107 measurements to establish a local coordinate system.

The Gnalić shipwreck was discovered by sport divers in the early 1960s, lying at a depth between 25 and 29 meters, near the Gnalić Island.
Archaeological remains of a large ship dated to the late 16th century.

This audio-visual work was composed by Kotaro Yamafune as a part of primary results of Gnalić Project 2014 field season. Original 3D models of the shipwreck site was created by multi-image photogrammetry. These models contain exact 1;1 scale dimensions, hence models can be used as archaeological data, and any measurements that archaeologists want can be extracted using the modeling software.

Yamafune also wants to give special credits to Sebastian Govocin (Fabe) and Rodrigo Torres as chief photographers of this Computer Vision Photogrammetry. And Rodrigo for creating Control Network which is critical process to create 1/1 scale models.

On December 2012, a joint team composed of the Netherlands (Dutch Cultural Heritage Agency), the United States (Texas A&M University), and Brazil (the Museum of Archaeology and Etnology at University of Bahia) carried out an expedition on the 17th century Dutch shipwreck off the coast of Salvador, Bahia, Brazil. The project was directed by Brazilian Ph.D student (2012) of the Nautical Archaeology Program at Texas A&M University, Rodrigo de Oliveira Torres. During the 6 days of underwater research, the team collected more than 300 measurements and 200 photos of the site and artifacts.
Using the data collected, a Ph.D. student of the Nautical Archaeology Program at Texas A&M University (2012), Kotaro Yamafune, reconstructed the Utrecht shipwreck site in 3D.

On December 2012, a joint team composed of the Netherlands (Dutch Cultural Heritage Agency), the United States (Texas A&M University), and Brazil (the Museum of Archaeology and Etnology at University of Bahia) carried out an expedition on the 17th century Dutch shipwreck off the coast of Salvador, Bahia, Brazil.The project was directed by Brazilian Ph.D student of the Nautical Archaeology Program at Texas A&M University, Rodrigo de Oliveira Torres.

During the expedition, Jens Addeld and Siaska Castro translated primary sources into English language. Based on these primary sources, Torres, Affeld, and Yamafune interpreted battle sequences of the Battle of Itaparica and created an explanatory animation.

In the summer of 2011, Texas A&M University and ProMare were invited to participate in the excavation of a Roman barge in the Stella River of Northern Italy in a joint project with University of Udine. The expedition was directed by Professor Massimo Capulli from the University of Udine and Professor Filipe Castro from Texas A&M.

This small boat (dated 1st quarter of the 1st century) was built following a construction technique typical in the region of the Upper Adriatic Sea; its planks were sewn together and fastened to solidify timbers.
Sewing planks to build ships was used in the Mediterranean from at least the 7th century BCE. When Rome started its career, there were 3 great naval nations: The Greeks, The Phoenicians, and The Etruscans. In those nations, ships were sewn together.
This technique was replaced by “pegged mortise-and-tenon” joinery by the 3rd century BCE in the Mediterranean waters. Intriguingly, the sewing construction survived until the 6th century CE in the Upper Adriatic region. The Stella 1 Wreck is an important example of Adriatic sewn ship construction.

Although, Deane’s manuscript was written to explain hull design of the 3rd rate warship, these dimensions of the ships are primarily based on ratio, not measurements presented, therefore it can be applied to 1st – 4th rates ship.
As I understood Deane’s descriptions, shapes of frames of the entire hull were designed by four arcs/circles of different radius. This indicates shipwrights only required four molds to design and cut frames of a ship. Additionally, positions of the four arcs/circles were controlled by four lines: rising of the floor, narrowing of the floor, rising and the greatest breadth, and narrowing of the greatest breadth. These lines were drawn with the Pythagorean Theorem. Dean’s design of naval warships was quite simple, yet one of the most sophisticated design.

Radius of Arcs/Circles (Deane’s 3rd Rate Warships)
Light Green = 9 ft.  Dark Green = 7 ft.  Purple = 20 ft.  Orange = 17 ft.

The Portuguese India naus developed from Mediterranean round ships, which were adapted to the Atlantic conditions. Naus gradually grew in size over the course of the 16th century, especially those engaged in the lucrative Asian trade. Most historians believe that the Portuguese used this type of ship in the trade with Japan. Naus were generally three-masted vessels with three or four decks their size varied from 300 to 600 tons burden; the word ‘nau’ means ‘vessel.’ Naus were called Nao in Spanish, Carrack in English, and Carraca in Italian.

This 3D model of Portuguese nau was originally created as the final project of ANTH610: Outfitting and Sailing the Wooden Ship, 1400-1900 (Nautical Archaeology Program). Dimensions and rigging arrangements of the model are based on historical references and archaeological data.

In June 2015, Texas A&M University hosted a field project at Shelburne Bay, Lake Champlain. This field season focused on Wreck 2, a steamboat most likely from the 1830s. After its retirement, the steamer was sunk intentionally to provide a wooding dock for the working steamboats (as evidenced by mountains of stone!). The site at Shelburne Bay, occupying an area only 100m by 150m, contains three steamers all built in the 1830s. These excellent archaeological examples provide us with a concentrated look into the early development of steamboat construction in North America’s inland waterways.
Along with manual recording by archaeologists, the team applied photogrammetric recording to Wreck 2 (Agisoft PhotoScan). The goal of this recording was to create an accurate 1/1 scale constrained model to use as archaeological data. To create a 1/1 scale constrained model, the team applied Direct Survey Methods (SiteRecorder) and collected 107 measurements to establish a local coordinate system

This triangular wooden feature was found on the starboard side of the stern of Wreck 4 (Whitehall [1837]). At first, we believed this piece was a part of a hog truss, however it was too large. Second, we thought that perhaps this was the A-frame that held up the diamond of the walking-beam engine, but it was too small. With the help of some images from the Boulton & Watt collection, Montreal steamboat scholar Jean Belisle was able to help us identify this as one of the paddle wheel boxes’ support frames.
- text by Carolyn Kennedy

This photogrammetric model of a Chinese Yangtze River boat was created as an author’s experiment. The sail of the model was created in different modeling software, then the model was re-imported into PhotoScan to create textures. Also, green-screen studio was applied to capture bottom surfaces to be structured in a single process

This boat model is a one of the Spencer Collection. The Spencer Collection was built in China between 1934 and 1940, and offered to Texas A&M University in 1974. It was made by a professional model builder from the port of Yichang, on the Yangtze River. It is composed of 29 boat models, all built after watercraft types that sailed on the Yangtze River. A book has been published by Joseph E. Spencer about this collection

"The Kyrenia ship sank during the last decade of the fourth century B.C. near the town Kyrenia on the North coast of Cyprus, probably the victim of an attacked by pirates. It was discovered about 1 km offshore at a depth of 30 m, and it was excavated in 1968 and 1969 by a team of nautical archaeologists under the direction of Michael L. Katzev. More then half of the hull had survived in relatively good condition and those timbers represented at least 75% of the original structure. After extensive seabed recording, the wood was raised, preserved in polyethylene glycol, and reassembled in Kyrenia's Crusader Castle, where it is displayed with cargo and artifacts from the wreck."

STEFFY, J. R. (1994). Wooden ship building and the interpretation of shipwrecks. College Station, Texas A & M University Press, page 42-55.

Hull lines are not only a representation or a designing tool for ships, but also the fundamental analyzing tool for Ship Reconstruction.


Recommended Drawing Order
1. Baselines on the sheer, the h-b (half-breadth), and the body plans
2. A keel and posts on the sheer and the body plans
3. Sheer lines on the h-b and the sheer plans
4. Section lines on the sheer and the h-b plans
5. Midship section on the body plan
6. Sheer lines on the body plan
7. Transom lines on the body plan
8. Transom lines on the h-b plan
9. Waterlines on the sheer and the body plan
10. Tentative section lines on the body plan
11. Tentative waterlines on the h-b plan
12. Fix the h-b plan’s waterlines
13. Fix the body plan’s waterlines
14. Buttock lines on the body and the h-b plans
15. Buttock lines on the sheer plan
16. Fix section lines on the body plan if needed
17. Diagonal lines on the body plan
18. Diagonal lines on the h-b plan
19. Deck lines on the sheer, the body, and h-b plans

Hull lines are not only a representation or a designing tool for ships, but also the fundamental analyzing tool for Ship Reconstruction of any types of shipwrecks including ancient ships.

Recommended Drawing Order (by the author)
1. Baselines on the sheer, the h-b (half-breadth), and the body plans
2. A keel and posts on the sheer and the body plans
3. Sheer lines on the h-b and the sheer plans
4. Section lines on the sheer and the h-b plans
5. Midship section on the body plan
6. Sheer lines on the body plan
7. Waterlines on the sheer and the body plan
8. Tentative section lines on the body plan
9. Tentative waterlines on the h-b plan
10. Fix the h-b plan’s waterlines
11. Fix the body plan’s waterlines
12. Buttock lines on the body and the h-b plans
13. Buttock lines on the sheer plan
14. Fix section lines on the body plan if needed
15. Diagonal lines on the body plan
16. Diagonal lines on the h-b plan

The Athlit Ram was discovered in 1980 at Athlit, Israel. Ramming was a naval tactic in ancient Mediterranean that strikes enemy’s hull using its own ship as a weapon. The Athlit Ram is dated abound 530 B.C. It was probably equipped on a quadrime (4 banked warship) or a quinauereme (5 banked warship). All what preserved was a beautiful bronze ram and its internal timbers. This archaeological evidence indicates that the ram and internal timbers were functionally designed to deliver striking force into enemy ship’s hull, yet destructive recoiled impact would be efficiently distributed into longitudinal timbers to prevent own damages.

This 3D model was created to visualize structural functions of the ram and mechanical function of the internal timbers. The model was created in Rhino3D CAD modeling software based on archaeological notes of J. Richard. Steffy, a founder of Ship Reconstruction Laboratory at Texas A&M University.

1:1 scale constrained photogrammetric model with modified Textures.
Original photogrammetric model of the Heroin shipwreck pork barrel and its orthophoto based artifact drawing were created by Carolyn Kennedy, a Ph.D. student in Nautical Archaeology Program under directions of the author.

This 3D model of the Flagpole was created as a part of Architecture 647: Recording Historical Building course at Texas A&M University (Summer 2014).
The White cement base of the flagpole in front of the Administration Building was a gift from the class of 1934. Three sides are figures depicting the components on which Texas A&M University was founded: military, mechanics and agriculture. Military is represented with a soldier. One woman holding a wheel portrays mechanics. Another woman distributing seeds from a satchel and standing wheat illustrates agriculture. The fourth side lists all the college presidents from 1876 to 1934. The bottom of the base forms a star, allowing the monument to function as a bench.

In the summer of 2011, Texas A&M University and ProMare were invited to participate in the excavation of a Roman barge in the Stella River of Northern Italy in a joint project with University of Udine. The expedition was directed by Doctors Massimo Capulli from the University of Udine and Filipe Castro from Texas A&M.

Following the summer season of 2011, graduate students of Texas A&M University Ralf Singh-Bischofberger and Kotaro Yamafune built a 1:5 scale restored model of the Stella 1 wreck.

During the last decade, the quality and availability of 3D software has opened up new avenues of research in nautical archaeology. This software permits a quick and relatively easy implementation of corrections, as well as the testing of hypotheses generated from unclear written sources, both textural and iconography.
Moreover, high-end reconstructions of archaeological ships are effective tools to discuss and improve knowledge about shipbuilding, both at scholarly and general levels.

In 1543, Portuguese sailors first reached Japan. They introduced the fire-weapon ‘arquebus’ (ancestor of rifles) to the Samurai world.
After this encounter, many Portuguese merchants and missionaries traveled to Japan and started the Far Most Eastern Trade with Japan.
Many Japanese artists in the 16th and 17th centuries depicted Europeans on screens, and those soon became popular entertainment. Those pieces are called ‘Namban Screens’.
Today, more than 90 of them survive in the world.