Augmented Reality Applications In The World Heritage Iwami Ginzan Silver Mine
1Keisuke Kimoto1* and Shozo Nishimura1 and Shunsuke Aoki2
Keisoku Research Consultant, Co., 1-665-1, Fukuda , Higashi-ku, Hiroshima, Japan,
kimoto@krcnet.co.jp, nisimura@krcnet.co.jp
2
General Officer in Board of Education, Ohda City Office,

ABSTRACT
Although CG and AR techniques are inferior to actually reconstructing the excavated sites, they
are an increasingly popular tool for people to view their world through the cameras of theirsmartphones and tablets while overlays of additional digital information augment that view. The
techniques have distinct advantages in their abilities such as displaying a replicated reconstruction of
the excavated scene with additional information in real space. AR also provides for quick andcost-effective information updates and, particularly, the ability to modify a excavation scene without
damaging the remains.This article describes two types of positioning for augmented reality systems marker and markerless (use of GPS) - to provide visitors a visual understanding, in real space on a PC
(Windows) or tablet terminal (iOS, Android) environment, of information obtained from excavation
about the site’s remains augmented with historical background facts.
Keywords: Augmented Reality, marker, World Heritage Iwami Ginzan Silver Mine, mock-up model
1. INTRODUCTION
The Iwami Ginzan is a historic silver mine of great importance to Japan’s cultural and industrial
heritage. It was one of the world’s top producing silver mines at its peak in the 17th century, supplying
about a third of the world’s silver production from the mountains of Shimane Prefecture, on the mainisland of Honshu. The mine site’s significance was recognized in 2007, when it was inscribed on theWorld Heritage List as "Iwami Ginzan Silver Mine and its Cultural Landscape.” It is Japan’s 14th
World Heritage Site and the first mining site to be inscribed in Asia.
Since then, the Iwami Ginzan World Heritage Center and local volunteers have collected valuable
information about the mine site for visitor exhibits as part of rigorous efforts to boost tourism andconvey the importance of preserving the nation’s cultural assets. But the excavated edifices andartifacts of the large mines, smelting and refining sites and mining settlements that comprise thetwo-square-mile, heavily wooded heritage site are widely dispersed, making it difficult for tourists tosee all the area’s attractions during a short visit. There have also been many attempts to reconstruct thesite’s remains, but the costs for reconstruction and maintenance, and managing both, are tooprohibitive.
To overcome these challenges, the authors of this article sought to provide visitors informationfrom excavations at the Iwami Ginzan Silver Mine by combining computer-generated (CG) animationand contextual digital information using augmented reality (AR) technology.

Ishigine RuinsShimizudani Refinement Ruins

Figure 1. Map of the Iwami Ginzan Silver Mine Site

2. OUTLINE
2.1 Marker-type AR using the model (Shimizudani Refinement Ruins)
The Shimizudani Refinement Ruins are what is left of a refinery built in 1893 on the northernside of Mt. Sennoyama. It includes a miner's residence, a substation, a sifting area and a trolley track.
The original construction also included eight layers of stone walls built at a height of about 100 feetand encompassing an area of nearly 75,000 square feet. Today, just a stone wall is left.
The authors used current drawings, documents and video production from the World Heritage
Center and reproduced images of the original building using marker-based AR to display informationfor visitors in the real space by recognizing a marker (or target on the scene) through a tablet
computer.
2.2 Markerless (GPS) AR (Ishigine Ruins)
The historic Ishigine Ruins were once a town with a silver refinement factory on flat terrain at thesummit of Mt. Sennoyama. Archaeologists excavated a six-foot-wide road in the center of the valley
revealing the remains of a tunnel and several buildings used to produce silver hundreds of years ago.
Inside, they found a grinder to crush ore (called a Konashi) and gravity concentration (calledYuriwake) and silver refining furnaces.
Using AR, the authors of the article reproduced one of the buildings (called Fukiya) withcomputer graphics that included depictions of workers from the mine’s golden years. Using the tablet’s
GPS camera, coordinates were calculated and markerless AR was carried out. As a result, visitors wereable to view images and animation explaining how the ancient structures were utilized to produce
silver as well as sightseeing navigation tools.

Figure 2. Shimizudani Refinement Ruins

Figure 3. Ishigine Ruins

3. APPLICATION DEVELOPMENT
3.1 Marker-based AR
The workflow to create AR at the Shimizudani Refinement Ruins is described below:
Producing a mockup modelCG

Field survey

Create a building model

Adjustmentof coordination for AR

3D laser scanning(LMS-Z420i㺂FARO)
Create a 3D surface model
contour line
adjustment a number of polygon

ARApplication Development
Create a marker

Conversion of dataOut put a mockup model
Clear coat

After the tablet’s camera
confirms the marker’s location
as a standard position, the CG
image is displayed in theterminal.

Figure 4. The workflow of Marker-based AR

3.1.1 Producing a mock-up model
Using data of the excavation scene
captured by a laser scanner, the authors
created a 3D surface model to accurately
reproduce the topography and original stone
walls of the Shimizudani Refinement Ruins.
The 3D surface model was then transferred
to a 3D printer, which spread thin layers ofgypsum powder and adhesive to make asolid surface model.

416mm

3D laser scanning data
588mm

  Figure 5. mock-up model

3.1.2 Production and adjustment of the marker
This marker-based positioning system requires locating predetermined coordinates of a target
image, or marker, on the scene with the tablet’s camera for positioning verification. In this case, a signplate was the marker in the scene. The tablet’s camera located and captured the marker’s coordinatesin the excavation scene, sending the captured image data back to the tablet to execute the augmented
reality program’s code.
Our AR application used an iPad tablet as the base terminal. Qualcomm's Vuforia AR software
was chosen as the the image recognition software to recognize the marker and receive the camera’s
captured image data, which was converted into a 3DCG model by Autodesk’s 3ds Max software. A
customized REMO AR Viewer was used to view the 3D model as AR CG content on the iPad.
3.1.3 Adjustment of coordination for AR
After the tablet’s camera confirms the marker’s location as a standard position, the CG image isdisplayed in the terminal.
Correct position

Monitor for AR

Surface data
Adjustment ofcoordination
Pedestalmarker

4th grade

Figure 6. The result of evaluation

Figure 7. The relation between a marker and location

3.2 GPS-based AR
Based on information from the excavation, a CG image of the Fukiya building image isreconstructed virtually. In this virtual Fukiya building, CG workers are depicted using the ancientequipment and machinery to illustrate and explain the silver production process. The CG guide tool
also uses dynamic animation in the scene to provide visitors with an enhanced view and morecomprehensive explanation of Shimizudani Refinement.
3.2.1 Tablet position adjustment
This method uses GPS information
received by tablet to determine a visitor’sposition. Because of the lower precision of GPS
coordinate information of "altitude", some
supplemented consideration is required
especially for "altitude" from our experience. It
was decided to input the visitor’s height data
into the calculation for more accurate
positioning.

GPSLongitude Latitude Altitude

CG is not stabilized in
an assumption altitude.

Figure 8. Altitude information from GPS

3.2.2 Contents production
In conjunction with a CG image depicting workers, we produced animation to view beforehandthat further explains to visitors the work process at Fukiya.
3.2.3 Adjustment of coordination for AR
There are several factors that can affect the accuracy of a GPS signal including errors in calculating
placement, errors in timing, the weather, and shifts in satellite orbits. Without the use of a marker, andto ensure the accuracy and precision of positioning, we repeated adjustment trials of coordination forAR.

Figure 9. Adjustment of coordination

Figure 10. The monitor of tablets(AR application)4. SUMMARY AND FUTURE DEVELOPMENT
The Iwami Ginzan World Heritage Center has collected numerous artifacts and information for
visitor exhibits at the historic silver mine. But the site’s remains are spread out over a mountainous,
two-square-mile area, making it challenging for visitors to get a full understanding of the importanceof the site’s cultural and industrial heritage. To solve the problem, two types of positioning foraugmented reality systems - marker and markerless (use of GPS) - were created to provide visitors avisual understanding, in real space on a PC (Windows) or tablet terminal (iOS, Android) environment,of information obtained from excavation about the site’s remains augmented with historicalbackground. Currently, visitors have access to specially prepared tablet terminals at the site. Futureplans include developing advanced AR technology so visitors can use their own tablets to accessvarious tools and resources relating to the World Heritage Site, including a mapping application,
guided tours and other information, all stored in one database.
To realize our goal, accurate positioning
information is critical. Furthermore, we have toThe image displayed on ipad
develop more attractive, visual content such as
simulating the experience of being inside a caveControl the Ipad
using panoramic images, bird’s-eye views of themine using UAV data collection, and simulationsin the virtual space using 3D laser-scanned dataand panoramic images. We will continue ourefforts to develop new AR technologies toconvey the importance of Japan’s cultural assets
and values, particularly those of the Iwami
Ginzan Silver Mine, more effectively to the nextgeneration.
Figure 11. Marker-based AR
REFERENCES[1] Iwami Ginzan Silver Mine and its Cultural Landscape:
http://ginzan.city.ohda.lg.jp/wh/en/index.html (accessed on 31st August 2013).