CSIS Discussion Paper #13

CSIS Discussion Paper #13

VIRTUAL RYOANJI PROJECT: Implementing a Computerassisted Collaborative Working Environment of a Virtual
Temple Garden
Atsuyuki Okabe, Shin-ichiro Sagara, Kei-ichi Okunuki, Teruhisa Kamachi
and Narushige Shiode

1999 年４月６日
The Department of Urban Engineering, School of Engineering,
University of Tokyo7-3-1 Hongo, Bunkyo-ku, Tokyo113-8656
e-mail: atsu@okabe.t.u-tokyo.ac.jp

Abstract: This paper introduces a simultaneous multi‑usersystem that enables collaborative work over the computer
network. In particular, we focus on the garden planning of a
traditional Japanese temple. We reproduced the stone garden of
Ryoanji Temple, Kyoto, in cyberspace using VRML and developed amulti‑user network tool that allows participants in different
locations to carry out a collaborative work of arranging stones
within this cyber‑garden. We added some new extensions on top
of Community Place browser (4), Sony Co., so that theparticipants could interactively reflect their actions andcommunicate simultaneously. The cyber‑garden model is written
in VRML 2.0 (9) and Java. The result of each collaborative
exercise is also uploaded on the Web in VRML format, and areaccessible by the general users using ordinary VRML browsers;
thus subject to public evaluation.
Keywords: 3D multi‑user environment, avatar manipulation,
collaborative work, cyber‑garden, VRML 2.0.

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1. Introduction
Rapid progress of the Internet has brought the possibility of computer‑assisted urban planning and decision making over the network. The three‑dimensional virtual environment, in particular, would give an
intuitively comprehensive solution to both the output and the process ofurban planning. It would also provide a better chance of citizen
participation where users could share a virtual space to present theirideas, discuss with each other and develop a collaborative work.
For instance, suppose that two people in different locations “log in” tothe same server machine from their local network computer. The servermachine would provide a “cyberspace,” i.e. a space shared in common byvarious users who are logged in via computer network. By manipulating
their own avatar, users can communicate with each other in the
cyberspace. VRML (Virtual Reality Modeling Language) (2), (8), (9) is atechnology that allows us to reproduce such cyberspace in the form of
three‑dimensional space similar to the real world. Changes in VRML and

Figure 1. Stone Garden of Ryoanji Temple, Kyoto, in the 16th century.

other Internet technologies are covered in the next section.
Our project focuses on the implementation of a simultaneous multi‑usercollaborative environment. As a first step to the implementation, we
will, rather than trying to create a full‑featured planning tool in asingle bound, focus on the garden‑planning model of a traditional
Japanese temple. Ryoanji, Kyoto, is noted for the beauty of its stone-2-

garden originally constructed in the 16th Century. Figure 1 shows theold record of the stones arranged in Ryoanji (Please refer to Appendix A
for the images of today’s Ryoanji). We reproduced the garden incyberspace using VRML and developed a multi‑user network tool thatallows several participants in different locations to carry out acollaborative work of arranging stones within this cyber‑garden. Eachparticipant is represented with an avatar so that their movements will
be clearly acknowledged by the others. By manipulating their own
avatars, the participants can "lift," "move" and "fix" the stones tobuild an ideal cyber‑garden of their own.
When fully developed, the Ryoanji model will be applicable tocollaborative working system for urban planning where citizens indifferent locations can simultaneously experience the virtual town
construction as if they are manipulating the real city. In the past,planners had to assemble in one place to draw maps and build models ofeach option; with the aid of a collaborative working tool, the entire
planning procedure could be carried out within virtual space withrelative ease. It would significantly promote citizen participation.
In the following sections, we will explain the details of our garden
planning tool. We will start off with the technical and social
backgrounds of our Ryoanji Garden Planning Tool. We will then go throughthe concept of the tool, the actual process of arranging the stones,
methods of exhibition and evaluation, the interface, possibilities of
future developments and conclusion, followed by an appendix of prototype
source code.

2. Technical and Social Backgrounds
First, we will briefly review the technical background of the Internet
service, especially that of VRML, and the application of World Wide Web
in urban planning both of which form the basis of our Ryoanji Garden
Planning Tool.
(1) Elements of Internet Service
Before the Internet was brought into the world, all computer terminals
were linked to those only within the same local network. They couldn’t
share information with computers connected to other networks, and each
network existed separately. However, once the Internet was built, all
the local networks were linked together; making every network computercapable of communicating with all the other computers even those on the
opposite side of the earth.
Initially, the kind of data exchanged was limited to ASCII codecharacters. Text files were transmitted by using network tools such as
ftp and telnet. Various E‑mail‑related services including network news-3-

and mailing list are the products of these days. As soon as the network
was opened to general and commercial use and the Web service wasintroduced, the Internet became remarkably popular. The Web service
enabled the exchange of multimedia contents; e.g. pictures, movies andsound. Thanks to the Internet, people could receive multimedia data fromany of the servers connected to the network.
Nevertheless, the pictures were still in the form of two‑dimensional
image and, apart from using few independently developed network
application tools, the former Vdream‑WIRL (6), for instance, it was
impossible to handle three‑dimensional objects via the Internet. It was
only after the VRML technology was established that three‑dimensional
objects could be obtained and visualised as Web contents. In fact, one
Web site has a VRML model of the Ryoanji Garden (7).
VRML itself has been updated considerably. The initial VRML technology(VRML1.0) (8) merely displayed three‑dimensional static scenes that are
sometimes referred to as walk‑through images. The next generation(VRML2.0/VRML97) (9), (10) acquired the ability to describe movements andplay background sounds in three‑dimensional space. Currently, the multi‑
user technology is being built into VRML (VRML 3.0) that lets multiple
participants share the same three‑dimensional space within the network(1), (3), (4). In the future, it may develop to a real‑time multi‑user three‑dimensional world under distributed system environment.
As the VRML technology develops, the difference between the space within
computer networks and that in the real world would become negligible.
Therefore, it is not difficult to assume that a new society, a cyber

Figure 2. Sharing the information between the users logged in the same cyberspace.

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Figure 3. Mechanism of interpreting the shared information.

society, similar to our real society would evolve in the network.
There are some other techniques that also support our Ryoanji Garden
Planning Tool. In order to control three‑dimensional scenes and the
movements within the space, we need to both describe the geometricshapes and record the movements. These tasks can be carried out by using
VRML, HTML (Hyper Text Markup Language) and Java language. We should
also keep control of the shared data so that the users within the same
cyberspace could share information in common. For instance, when one
user makes a movement, it should be acknowledged clearly by the otherusers. The piece of information concerning a user’s movement will be thus
controlled and maintained by the server machine and received by every
client system (Figure 2). In our Ryoanji project, we use network
software called Cyber Passage Bureau for handling the shared information
and a multi‑user VRML browser, Community Place (4), for interpreting thedata at the client side (Figure 3).
(2) Utilising the Internet for Urban Planning
In conjunction with the recent developments, the Internet technology is
gradually being adopted in the field of urban planning. The advantage ofusing it in urban planning process is that people located in different
places could make two‑way communications, even exchange information inreal time. When the Web service first came up, the urban planners did
not make the most out of this capacity of communicating in two‑ways and-5-

in real‑time. The municipal government of Sapporo City, Hokkaido, forinstance, provides various planning information including their
outlines, locations and duration through its Web site (5). However, since
it doesn’t accept any feedback from citizens, it provides only one‑sided
service. Two‑way communication has constantly popular in pre‑Web
services such as news or mailing list whereas the Web service seems tolack this aspect. Why, then, is the Web service so highly praised? Asaforementioned, the Web service is distinguishable from other Internet
services for its ability to transmit multimedia contents. Its popularity
originates in the potential of multimedia data; in other words, it could
be stated without exaggeration that only those who utilise multimedia
contents would make good use of the Web service.
Therefore, whether or not urban planners use the Internet efficiently
depends on how well they utilise all its features: two‑way transmission,
real‑time communication and multimedia data manipulation through the Web
service.
Recently, some governments and municipal authorities have launched atwo‑way urban planning communication scheme. In the case of Yamato City,
Kanagawa, they summarised their urban planning problems on a map,
uploaded the image onto their Web site (11), and accepted comments fromthe citizens. They built their master plans based upon this feedback,thus, succeeded in utilising two‑way multimedia communication. However,even in this case, real‑time three‑dimensional communication has notbeen adopted.
Our Ryoanji Garden Planning tool involves real‑time, three‑dimensional
data transmission and, in this sense, is in accordance with the trend of
utilising the Internet in urban planning context. In fact, when we thinkof the situation where multiple participants carry out a single task of
constructing an urban model over the network, the ability to communicate
in real time and to transmit three‑dimensional contents are crucial.
Once the urban planning support system is completed, we will be able toexchange three‑dimensional model of town plans in real‑time whereupon
there will be no more need to assemble all the participants in one placeat the same time.

3. Concept of the Ryoanji Garden Planning Tool
This section gives a brief introduction to the idea of our Ryoanji
Garden Planning Tool. Further discussion follows in the next section. As
mentioned, the ultimate objective of our project is to provide a full‑featured urban planning support system. One of the essential points
amongst all the factors in urban planning would be to gather a number ofpeople who may have all different concepts, views and standpoints andinduce them to cooperate in creating a single space.

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Focused on this point, we designed our garden planning tool tocorrespond to multiple participants (we will call them players) carryingout a collaborate task. We reflected the exchange of opinions anddifferent actions taken by planners with different roles in a usual
collaborative work onto the arrangement of stones in a virtual garden.
In order to make the player’s role distinctive, we assigned different
roles to each of them. Each player has a unique set of stones; the same
number of stones, but in different sizes and shapes. A stone can be
moved only by the player to whom it is assigned. By restricting“lifting” or “placing” other player’s stone, we can give different roleto each player. In other words, they can only complete the task bycomplementing and helping each other.
The process of collaborative work consists of four steps: discussion,
temporary placement, resolution and settlement. The stones will beplaced one at a time, and these steps are repeated for all stones.
Should, at the stage of resolution, the temporary arrangement be voted
down, they should start over from the discussion. These four steps
reflect the general process of urban planning. As we enhance these steps
to a more detailed, sophisticated scheme, this tool would be upgraded toan urban planning support system.
When all the stones are arranged and the stone garden is completed, theoutput will be exhibited in public and appraised as thus. This isequivalent to the public hearing of a proposal in urban planning. Basedon the results from public evaluation, players can give another try on
the arrangement. This step would equal to the process of feedback inurban planning.
In the following, we will explain the details of our Ryoanji Garden
Planning Tool. We will start off with the process of stone arrangment,
then the methods of exhibition and evaluation, the interface, andconclude with future developments.

4. Process of Arranging the Stones
The process of arranging each stone comprises of the following four
steps:(1) Discussion on preferable location(2) Temporary placement(3) Adoption of resolution(4) Final settlement

Players should follow these steps repeatedly for each stone. In thefollowing, we will explain each process in detail.

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(1) Discussion
Players will first discuss which stone to choose and then its
preferable location. The means of communication throughout this
discussion will be gestures made with their avatars as well as“chatting.” Chat is one of the common methods of communicatingover the Internet. Players “talk” with each other by typing
their words from their console and displaying them on a chatwindow. By manipulating their own avatars, they may also movearound the garden, change their viewpoints and communicate bygesture. Community Place of Sony Co., the browsing tool weadopted in this project, is equipped with a chat window.
(2) Temporary placement
As the talks come to a certain settlement, the players can try
placing the stone temporarily in the garden and see the result.
To avoid futileness, we will restrict the maximal number oftrials possible for each stone. In other words, players can go
through the process of arranging and discussing repeatedly, up
to a certain times. This trial and error would help the player
to develop a common plan with the others.
A stone temporarily arranged would be expressed in different
colour so that it could be distinguished from those that havebeen already fixed (Figures 4, 5).

Figure 4. Arranging the stone in -the8 - main window.

(3)Adoptionofresolution
After placing the
stone
on
a
temporarybasis,
the players should
proceedtotheresolution
anddecide whether the
temporaryplacementisadequate or not.
It would take theform of an open
vote by all theplayers. If theplayer agrees with Figure 5. Communicating in real-time.
thetemporarylocation,he/sheshould click “OK”
buttonand,
ifnot, “NO” button
shown
in
the
window (Figure 6).
The polling score
between pros and
cons
will
be
displayedinasmall sub‑window.
We adopted thisvoting system toavoid an arbitrary
decision made by asingle player. The
default setting requires approval by the majority of theplayers for passing it. If the temporary placement is voted
down, the players should start again.
(4) Final settlement
Once the resolution is passed, the stone is no longer moveable
and will be actually fixed to that location. Players cannot
proceed to the arrangement of the next stone until thissettlement is completed.

-9Figure 6. Communicatingin real-time.

As for the next stone, these four steps have to be followed in the samemanner, starting off with the discussion. After going through thisprocess for all the stones, the garden will be completed and exhibited.
The works will be uploaded on our Web site and will be subject to public
appraisal. In the next section, we will describe the method of
exhibition and evaluation.

5. Exhibiting and Evaluating the WorkAll the works, including those that are still under construction, will
be exhibited on our Web site. Using a VRML browser, visitors can,without actually taking part in the work, browse them over the Internet.
In fact, the visitors can see the work from the corridor as if they arewatching the original Stone Garden of Ryoanji. As they proceed along thecorridor, they will find different works displayed one after another.
As they keep walking down the corridor further on, they would comeacross the exhibition gallery full of completed works. All the results
will be shown with the creator’s name and their comments. Visitors canappreciate the completed stone gardens as if looking at pictures in anart museum.
After looking at the gardens, visitors can reflect their evaluation bycasting their vote for the best. There is no definite standard as to theevaluating process and it is solely dependent on the visitors’ judgment.
This is similar to the fact that there is no standard basis of judgement
in urban planning, and that citizens should rely on their own judgement
when evaluating the plans. The polling scores will be displayed in the
Web site in real‑time. We expect this public ranking will motivate theplayers, help us grasp the trend of evaluation, and increase thevisitors’ interests in participating. In the following, we will introduce
the actual interface.

6. The Interface
The interface of Ryoanji Garden Planning Tool consists of four window‑
typed frames. Their purposes and functions are as follows:(1) Main Window
VRML file is downloaded into this window and displayed as athree‑dimensional space. Players will be represented in theform of avatars and create the stone garden. Visitors, who are
not involved in the work, can also enjoy the same scene fromthe corridor.

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(2) Selection Window
This window displays a list of stones available. By clicking
its image, players can select which stone to be used next. Onceselected, the stone will appear in the main window.
(3) Action Window
This window is prepared for the players to make various complex
movements including “grabbing,” “releasing,” “lifting up,”“putting down,” “pushing” or “pulling” the stone. By selecting
the type of action from the list, the player can manipulate
her/his own avatar accordingly. Other simpler movements such as
moving to any four directions, looking up and down, or rotating
the body of the avatar are controlled from the console; i.e.
keyboard and mouse.
(4) Chat Window
This window shows the conversation made between the players.
Visitors can also read the lines, but they cannot take part in
the players’ conversation. The visitors can chat with eachother and reflect their opinion to the works by evaluating thecompleted works.

7. Future Developments and Possibilities
As mentioned above, Ryoanji Garden Planning Tool is our first step
towards the development of an urban planning support system. When fully
developed, this tool should acquire the main factors and stages in theactual urban planning process. It will not only assist the actual urban
planning steps, but also contribute to the understanding of the users’
behaviour and mentality within this wired space of computer network.
There are quite a few studies on human behaviour and the psychologicalaspects of the real space, but whether or not these results could beapplied to cyberspace remains an open question. Ryoanji Garden Planning
Tool may help us understand the unique features of the emerging virtualsociety.
Currently, we are thinking of carrying out a comparative study ofesthetic sense towards gardens in Britain and Japan through the garden
planning process. Ever since early times, Japanese tone has valued“Wabi‑Sabi,” the nicety of beauty that exists in simplicity andsubtlety. We find certain similarity in cultural background of Britain
and Japan; in fact, naïve factors such as elegant simplicity, subtlety or
cosiness are highly regarded in British culture. This sensitivity thatthe British and the Japanese share in common may count towards theirinterests in constructing the simple stone garden within the virtual- 11 -

space. Of course, these two cultures differ in many other aspects that
may result in forming different cyber‑cultures. Planning out the virtual
Ryoanji garden may help us measure such cultural similarity anddifference.

8. Conclusion
In this paper, we proposed interactive software for planning a stonegarden site. It was an enhanced VRML multi‑user tool with which
participants in different locations could simultaneously “log in” to thesame virtual space and carry out a collaborative work. The concept ofworking together in a virtual environment may not be new. As yet there
are only few planning tools that does not require any special equipment
and expenses (1), (3); and, in this sense, we believe our system has lived
up to the expectations.
Our aim is to construct a multi‑user interface that support the planners
carry out the urban planning process over the computer network. We
believe that Ryoanji Garden Planning Tool reflects the main scheme ofJapanese urban planning process and, therefore, qualifies as a prototype
model of a full‑featured urban planning support system. Moreover, it
would help us investigate the unique features of virtual society and its
culture. Study of cyberspace culture, particularly in terms of thedifference it holds against that in the real space, is an important
issue that should be investigated thoroughly to which, again, Ryoanji
Garden Planning Tool could make a contribution.

9. References (All Web URLs effective as of 6 January 1998.)(1) Active Worlds: http://www.activeworlds.com/(2) Ames, A. L., Nadeau D. R. and J. L. Moreland (1995) "The VRML
Sourcebook", John
Wiley & Sons, New York.
(3) Blaxxun Interactive: http://www.blaxxun.com(4) Community Place (Sony): http://vs.sony.co.jp/(5) Development Plans in City of Sapporo (in Japanese):
http://www.city.sapporo.jp/CityPlanning/City/DEVELOP/develop.html(6) Platinum WIRL: http://www.vream.com/3dl1.html(7)VirtualKyoto–
Ryoanji
Garden:http://www.planet9.com/earth/kyoto/index.htm
(8)
VRML
1.0
Specification:
http://www.webcity.co.jp/info/andoh/vrml/vrml110.htm(9) VRML 2.0 (VAG): http://vag.vrml.org/(10) VRML 97 Specification: http://www.vrml.org/Specifications/VRML97(11) Yamato City Urban Master Plan:- 12 -

http://www.city.yamato.kanagawa.jp/TOSI/TMP/e/index.html- 13 -

Appendix A – Pictures of Ryoanji Garden- 14 -

Appendix B – VRML Source Code Sample#VRML V2.0 utf8
PROTO Sony̲WorldInfo [field
MFString archive[]
field
SFInt32 armLength‑1
field
SFBoolavatarRoom
FALSE
field
SFInt32 backgroundImageType0
field
SFString cpBureau""
field
SFString cpBureauWLS""
field
SFBoolcollisionSound
TRUE
field
SFBoolcollisionDisplay
TRUE
exposedField SFBool
turnButtonAvailable
TRUE
exposedField SFBool
floatButtonAvailable TRUE
exposedField SFBool
homeButtonAvailable
TRUE
field
SFInt32 soundDeviceRate
22050
field
SFInt32 soundDeviceBits
8
exposedField SFBool
textureMagFilter
TRUE
exposedField SFBool
textureMinFilter
FALSE
exposedField SFBool
textureBlending
FALSE
exposedField SFFloat stereoViewRefDistance 2
exposedField SFFloat stereoViewEyeDistance 0.075
field
SFBoolcpb20MaterialColor
FALSE
]{}
PROTO Sony̲BindSharedNode [field SFNodetransformNode NULL
field SFNodescriptNode
NULL
field
MFString
actionHello,sonybrowser:Hello,,,;Smile,sonybrowser:Smile,,,;Wao!,sonybrowser:Wao,,Wao,;
Umm...,sonybrowser:Umm,,Umm,;
Wooo!!,sonybrowser:Wooo,,Wooo,;
Bye,sonybrowser:Bye,,,;"] {}Sony̲WorldInfo {cpBureau "127.0.0.1:5126"
avatarRoom TRUE
armLength 25
soundDeviceRate 22050- 15 -"SonyActionPanel:soundDeviceBits 8}
WorldInfo {title "ryoanji"}
NavigationInfo {type "WALK"
headlight FALSE}
Background {skyColor 0.1 0.1 0.7}
Viewpoint {position 0 4.1 10}
PointLight {location 0 10 ‑10}
PointLight {location 0 10 10}
DEF YUKA Transform {children [Shape {
geometry Box {size 50 0.1 50}
appearance Appearance {texture ImageTexture {url "../paper01.gif"}
textureTransform TextureTransform {scale 1.0 1.0}}}]- 16 -

}
DEF TATEMONO Transform {translation 0 1 0
children [DEF TS TouchSensor {}Shape {
geometry Cylinder {}appearance Appearance {material Material {diffuseColor 0.5 0.5 0
}
}
}
]
}
DEF ROCK Transform {children [Transform {translation 0 0.125 ‑2children [DEF Rock1 Shape {geometry Sphere { radius 0.25 }appearance Appearance {texture ImageTexture {url "../stone.gif"
}
}
}
]
}
]
}
Transform {translation 2 0.5 3
children [DEF Rock2 Shape {appearance Appearance {texture ImageTexture {url "../stone.gif"}}- 17 -

geometry Cone {height 1
bottomRadius 0.5}}]}
Transform {translation ‑2 0.5 ‑2children [USE Rock2]}
Transform {translation ‑10 0.125 ‑10children [USE Rock1]}

DEF PSENSOR ProximitySensor {size 100 100 100}
DEF RockScript Script {directOutput TRUE
url "scripts/RockScript.class"
eventIn
SFVec3f avatar̲position
field
SFNoderockNode USE ROCK
eventOut SFVec3f rock̲position̲out
eventIn
SFString rock̲position̲in
eventIn
SFRotation avatar̲orientation
eventIn
SFString rock̲orientation̲in
eventOut SFRotation rock̲orientation̲out}Sony̲BindSharedNode {scriptNode
USE RockScripttransformNode
USE ROCK- 18 -

action"SonyActionPanel:
Smile,sonybrowser:Smile,,,;Umm...,sonybrowser:Umm,,Umm,;
Bye,sonybrowser:Bye,,,;"}

Hello,sonybrowser:Hello,,,;Wao!,sonybrowser:Wao,,Wao,;
Wooo!!,sonybrowser:Wooo,,Wooo,;

ROUTE PSENSOR.position̲changed TO RockScript.avatar̲position
ROUTE RockScript.rock̲position̲out TO ROCK.translation
ROUTE PSENSOR.orientation̲changed TO RockScript.avatar̲orientation
ROUTE RockScript.rock̲orientation̲out TO ROCK.rotation

Notes
(1)
The
node
named
Sony̲WorldInfo,Sony̲BindSharedNodewasindividually developed by Sony Co. for its multi‑user VRML browser,
Community Place. Users will gain access to the server machine byspecifying the name of the server in the cpBureau field of theSony̲WorldInfo node.
(2)
The garden scene is set up by various fields including Background,
PointLight and Viewpoint; these fields are used for determining thebackground colour, location of the light source, and viewpoints of theavatars, respectively. Textures are mapped onto the floors and stones
to make the scene realistic.

(3)
The ProximitySensor gives the degree of nearness towards theavatar. As the user manipulates the avatar, this field would generate
its new coordinates (position̲changed event out) and its neworientation (orientation̲changed event out). And, whenever the avatar
moves a stone, the following Route command lines refer to this value
and give it to the script lines that the calculates the newcoordinates of the stone.
ROUTE PSENSOR.position̲changed TO RockScript.avatar̲position
ROUTE PSENSOR.orientation̲changed TO RockScript.avatar̲orientation(4)
In the Script nodes, position of the script is specified in the
URL field, the variable to be given in the eventIn field, and thevariable to be fed back in the eventOut field, respectively. (The word
script refers to an external Java programme source). The scripts would
feed back the coordinates and the orientation of the stone. These- 19 -

values are passed onto the following Route command lines whereupon thestone is redrawn in the scene:
ROUTE RockScript.rock̲position̲out TO ROCK.translation
ROUTE RockScript.rock̲orientation̲out TO ROCK.rotation- 20 -