Paper Visualizing Anuradhapura

7/31/2019 Paper Visualizing Anuradhapura

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Visualization of Ancient Anuradhapura: ADemonstration of Digital Possibilities

Prasad Samarajiva1

, ChandimaAmbanwala2, Anuradha Piyadasa3

Due to human activities and natural processes ofdecay, many of the past superstructures inAnuradhapura are no more. Only a fewremaining structures point to the glory of thepast. Visitors are intrigued by the remainingsuperstructures and ancient foundations. Readinghistorical texts as well as recent archaeologicalpublications would fill in some of the gaps to thevisitor. In addition, the limited replicas of thestructures found in museums also help to somedegree. But the visitor's visual understanding isstill limited.

In the past few years, computer aided three-dimensional (3D) visualization has beengenerated for some notable sites in the West,such as ancient Rome and ancient Greece. Theygive a vivid display of these sites, especiallywhen some of these reconstructions areaccompanied by virtual reality. The

reconstructions present an immediacy which nohistorical or archaeological text could provide.

1 Royal Asiatic Society of Sri Lanka, Email:[email protected] Archaeology.lk, Email: [email protected] Royal Asiatic Society of Sri Lanka, Email:

[email protected]


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As a first experiment, our team has attemptedto visualise aspects of ancient Anuradhapurathrough computer aided 3-D technology

combined with global positioning. We havedeveloped the remaining structures usinghistorical texts as well as recent specialisedpublications. We thus developed 3D models forparts of ancient Anuradhapura using satelliteimages, photographs, and the commonlyavailable 3D visualization software called GoogleSketchup. In addition to computational graphical

tools, the combined knowledge of history,archaeology, architecture, art, and engineeringwas used in this modeling to represent these paststructures in the most accurate way. Such directvisualization of ancient heritage sites can beleveraged to better study these places as well asto raise awareness in general on the pastAnuradhapura society, as well as to give support

for pilgrims and the tourism industry. Whentransferred to a mobile phone, they could directlyact as a guide to visitors on the site. The paperdescribes the process of computer visualisationand illustrates through a live demonstration ourmodel of Anuradhapura.

Keywords: 3D Visualization, Anuradhapura, Google

Sketchup, satellite images, photographs


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Introduction

A visitor walking through the innumerable ruins in

Anuradhapura, the ancient capitol of Sri Lanka, maybe intrigued to know how these structures appeared

in their glory days. Reading historical texts as well

as recent archaeological publications would fill in

some of the gaps to the visitor. In addition, the

limited replicas of the structures found in museums

also help to some degree. But the visitor's visual

understanding is still limited. As a first experiment,our team has attempted to visualize aspects of

ancient Anuradapura through computer aided 3D

technology combined with geographical positioning.

We have used the remaining structures combined

with historical texts as well as recent specialized

publications in this attempt. We thus developed 3D

models for parts of ancient Anuradhapura using

satellite images, photographs, and the commonly

available 3D visualization software called Google

Sketchup. Presented below is a synopsis of tools and

methodologies, together with examples from our

model of selected parts of ancient Anuradhapura.

3D Modeling Technology

Computer-Aided Drafting (CAD), is the use of

software and computer systems to create virtual

models of physical objects. Geometrical data of an

object is usually recorded in a numerical format

together with material data of the object. The

material data includes color and texture of the

material. In addition to the geometry and materialdata, environmental data such as light sources can


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also be introduced to the model. The software uses

these data and graphically renders the object on a

computer screen from one view point at a time.

Similar to a motion picture, continuous rendering ofan object from a trajectory of viewpoints completes

the virtual visualization of the object. However,

unlike a motion picture with a fixed trajectory of view

points, the rendering viewpoint of a CAD models can

be interactively changed by the end user, thus giving

a sense of virtual reality.

Most of the available software maintains elementary

objects like lines, squares, circles, polygons, cubes,

spheres, cones, and cylinders. State-of-the- practice

software has built in capabilities for the user to

create an object of choice using the elementary

objects. We used commonly available free software

called Google Sketchup (SU) in this attempt to

visualize parts of ancient Anuradhapura.

Geographically Referenced Modeling

Google Sketchup is a specially designed 3D modeling

software to work with another software system

called Google Earth (GE). GE in essence is a virtual

globe program that shows the earth bysuperimposition of images obtained from satellite

imagery, aerial photography, and geography over a

3D globe. However, the data for GE is mainly stored

in remote computer system since a current day

personal computer is not sufficient to maintain such

a vast collection of information.


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SU can interact with GE to create global positioned

models. SU can selectively copy the terrain, and

imagery of a given geographical area from GE. Such

methods simplify the modeling process since thelayout and dimensions of a structure are readily

available. In the case of SU, it is possible to

superimpose one or many developed models in GE

for visualization. Such capabilities provide a highly

conducive environment for collaborative

development and sharing of models. Development

of the Jethavana Monastery of ancient Anuradhapurausing SU, GE, photography, and knowledge of

archaeology is described in ensuing sections.

Model Development

For the sake of simplicity, we selected the Jethavana

Image House (pathimagara) located within the

Jethavana Monastery for this illustration (Figure 1).This is a typical Anuradhapura and Polonnaruwa era

stone foundation and brick masonry structure.

Typical to an image house, the vestibule of this

structure leads to a circumambulatory pathway

around an inner chamber. The main entrance to the

image house is a 27 feet tall opening with monolithic

stone jambs. Fragments of the stone door headerappear to be still sitting on the vestibule floor. A

few complete stone window and door frames remain

intact to this day. A partially destroyed, perhaps by

treasure hunters, lotus pedestal (padmasana) is still

present in the inner chamber. Based on the size of

the entry door and the size of the lotus pedestal, the


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height of the original Buddha statue is estimated to

be about 37 feet (Seneviratna, 1994).

The original roof could have been a vaulted brickmasonry or a traditional timber hip roof cladded with

clay tiles. Based on Bandaranayake (2009), a

decently preserved roof structure from late

Anuradhapura era cannot be found present day.

Readership may wonder why walls of the image

house was abnormally wide. One possibility is that

the walls were widened to support the masonry

dome. However, the primary author is of the

opinion that the ancient builders thickened these

unbraced tall walls to provide adequate resistance

against lateral wind forces than to support the dead

weight of a masonry dome. Therefore, in the

current form, we assumed that there was a

traditional timber hip roof cladded with clay roof tiles

over the Jethevana Image House.

Senevirathna (1994) speculates this structure to be

the Manimekhala Pasada built by king Sena I in the

9th Century CE. C ava sa reports that the image

house was destroyed by Chola invaders during the

reign of Udaya IV (946-954 CE) and the king partly

rebuilt it. King Mahinda IV has restored the structureonce again in the 10th century CE. Based on the

C ava sa, the colossal Buddha statue could have

been a gold painted limestone statue. In essence,

the present ruined structure is a result of recorded

activities of construction, destruction, and

reconstruction over the last two centuries of

Anuradhapura era and, unknown acts of destruction


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by humans and nature in the following centuries.

Now we proceed to build the 3D model of the

Jethavana Image House with sufficient knowledge of

the history of the structure.

Graphical Development

In the first step of graphical development, we used

the partial satellite view of the Jethevana Monastery

through GE (Figure 2). In addition, this view shows

the ruins of other buildings and parts of the

Jethevana Stupa at the western boundary of the

monastery. Direct access to a satellite image

simplifies the correct global positioning and

approximate dimensioning of the model. It is also

possible to use a digitally scanned plan of the

foundation layout over the satellite image for more

accurate dimensioning.

In the second step, we traced the foundation layout

and developed the building footprint (Figure 3). The

layout was adjusted by comparing the available

photographs for accuracy. It is important at this

point to paint the foundation segments with the color

and texture of the superstructure walls that are

going to be there.

In the next step, we developed the walls (Figure 4).

This was a conjectural reconstruction of walls was

based on our historical and engineering knowledge.

Addition of door and window frames ensued. A close

review of these frames indicates that there were no

hinges in these frames to install operable door or

window panes. As a result, we assumed that the


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image house was never built as a fully closed

structure.

Following the walls, doors, and windows, wedeveloped the roof based on our assumptions of the

roof type. However, the roof system was graphically

grouped for easy replacement with a different type

of roof when more accurate information will be

available in the future. Addition of the architectural

details like the half moonstones (sandakada pahana)

and the lotus pedestals ensued. We also added the

peripheral structures including the two smaller

structures and the parapet for visual completeness

of the model. At this point the model was ready to

be placed in GE.

In addition to the Jethavana Image House, a number

of other identifiable structures including the sthupa

were added to the model later on. Figure 7illustrates the overall view of the Jethavana

Monastery in its prime during the late Anuradhapura

era. Figure 8 illustrates sunrise at the Jethevana

Bodhighara Railing site with the sthupa in the

background. Figure 9 is a present day view of the

pond near the Jethavana Uposathaghara and Figure

10 is the pond as seen in the model.

Digital Possibilities

These digital models of the structures in

Anuradhapura have been developed with the

anticipation of further improvements. Most of these

models can be edited and improved upon discovery

of additional information. Currently these models


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are available in the Google 3D Warehouse

(http://sketchup.google.com/3dwarehouse - search

term Anuradhapura) for anybody to download and

edit. We envision development of the entire ancientAnuradhapura so that a viewer can visualize the city

and the structures in a chosen time period of our

illustrious history.

Conclusions

We developed 3D models for parts of ancient

Anuradhapura using satellite images, photographs,

and the commonly available 3D visualization

software called Google Sketchup. In addition to

computational graphical tools, the combined

knowledge of history, archaeology, architecture, art,

and engineering was used in this modeling to

represent these past structures in the most accurate

way. Such direct visualization of ancient heritagesites can be leveraged to better study these places

as well as to raise awareness in general on the past

Anuradapura society. In addition, these models can

be used to support the tourism industry. When

transferred to a mobile phone they could directly act

as a guide to visitors on the site.

The current development is an effort by a handful of

volunteers with the interest in archaeology. We

envision further developments in a global

collaborative environment of volunteers.


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References

C avamsa: being the more recent part of the

Mah vamsa, Part 1, Wilhelm Geiger, Ceylon Govt.

Information Dept., 1953

Ancient Anuradhapura the Monastic City, Anuradha

Seneviratna, Archaeological Survey Department,

Colombo, Sri Lanka, 1994

Sinhalese Monastic Architecture: the Vihras of

Anurdhapura, Seneka Bandaranayake, OrientalBlackswan Private Limited, Hyderabad, India,

2009

Figure 1. Composite of Photos of the Jethavana

Image House


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Figure 2. Geographically Referenced Satellite Image

of the Jethavana Image House Captured by SU

Figure 3. Development of the Footprint of the

Jethavana Image House based on the Satellite

Image


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Figure 4. Development of the Superstructure of theJethavana Image House

Figure 5. Completed Superstructure of the

Jethavana Image House


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Figure 6. Illustration of Architectural Details of the

Jethavana Image House

Figure 7. Overall View of the Jethavana Monastery


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Figure 8. Sunrise View of Jethavana Bodhigara

Railing Site

Figure 9. Present Day View of the Pond Near the

Uposathaghara


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Figure 10. A Model View of the Pond Near the

Uposathaghara

Documents

Paper Visualizing Anuradhapura