Laying 3DML Interface Groundwork fora Distributed Digital City Kyoto
Stefan Lisowski* and Kaoru Hiramatsu**
NTT Open Laboratory, 2-4, Hikaridai, Seika-cho, Soraku-gun, Kyoto 619-0237 Japanlisowski@digitalcity.gr.jp, hiramatsu@digitalcity.gr.jp
Introduction
In this paper we’ll present our designs for a 3D interface to online
Digital City Kyoto. Digital City Kyoto is a new approach to creating
an on-line city resource. The key principles guiding the design of thissystem are that it be community based and enable a dynamic, bottomup collection of practical information. Communities that flourish arethose that have multiple uses and can be modified and adapted by residents for diverse purposes not necessarily anticipated by their makers[1]. Participation and visionary ideas from users are essential to thehealth of Digital City Kyoto.
The initial interface to the Digital City Kyoto is a scalable and intuitive
3D interface, which will lay the groundwork for distributed expansion
and easy access to this geographically-bound information. The 3DML
language has been selected for the initial phase to increase community
participation in the development of the project.
In this paper we’ll comment on why 3DML is a good choice for a distributed production model and describe how our prototype works andhow it links to web information. We’ll touch on our plans for distributed construction. We’ll also describe a virtual bus tour feature, andconclude by describing future plans.
3-D Platform Choice
3DML was the chosen as the tool to create the 3D portion of Digital
City Kyoto. The 3DML plug-in provides Doom or Quake-like 3D
motion and interface. This tool was selected for a variety of reasons.
The main goal was to allow many people to work on this city in orderto take advantage of distributed authoring, therefore the authoring
tool needed to be quick to learn and work well with web standards.
Although VRML was designed to fill this niche, there is not widespread use of it. This may be due in part to the fact that a good
VRML site requires skilled 3D modelers and skilled programmers.
3DML allows rapid creation of web based 3D areas by anyone withthe skill to build their own web site. 3DML allows graphics and photos to be mapped onto blocks and rotating planes, creating a geometrically rough city space while VRML allows for geometrically precise figures. Though VRML would be far superior formodeling a car, to represent an entire city 3DML has
sufficient resolution and allows for rapid construction.

A 3DML rendered spot can appear in any web page window, it integrates well with other technologies. For example, we used
Microsoft’s free web Agent with Internet Explorer, as well as
Acuity’s Java based Ichat technology which an individual may makeuse of simultaneous to exploring the 3D environment. 3DML is alsoeasy to parse and manipulate with cgi programs.

Table 1, 3DML VRML Comparison
Recommended
Hard Disk Space
Precise Models
Learning Curve
Development Timefor a Building
Developers
RequiredEasy to manipulate with cgis?
Visual Example

3DML Rover Browser

VRML Cosmo Browser

approx. 1 - 2 mb
noshort14mb
yes
longhours
Someone familiar withbuilding a web sitedays
1 VRML programmer
1 experienced 3D modeler

yesnoBuilding 3D Kyoto
We chose the city of Kyoto for a number of reasons as well. Kyoto is
an interesting city that has a famous heritage and a beautiful landscape.
In addition to historical Kyoto, residents of Japan’s Kansai area frequently visit Kyoto to patronize its businesses. It is a thrilling moderncity as well as an international cultural resource.
Our prototype currently contains two different sites in Kyoto, viewable
on the Web at http://www.digitalcity.gr.jp. The first is Nijo Castle, apiece of historic Kyoto and an attraction to visitors from around theworld. The second site is the Shijo and Kawaramachi-dori area of thecity, where citizens of Kyoto and visitors from the surrounding areas
and beyond come for shopping, to see movies, and to eat.
The Nijo castle, Kawaramachi & Shijo 3D components were built bytaking a digital camera to the sites, and carefully photographing buildings and other features and attractions. Some of these photos were kept
FIGURE A, 3DML Syntax

See Figure A for an example of what makes 3DML sointuitive, and why anyone who can build a regularHTML site should be ready to produce a 3DML “spot.”
The 3DML plug-in is available at no charge fromhttp://www.flatland.com, and works for recent versionsof Internet Explorer and Netscape on the PC. 3DML isa simple to use text-based technology which requires
only a 600k plug-in for interpreting text pages and texture maps in 3D., and runs on any reasonably newPentium. The bandwidth consumed can be low as well,depending on the quality of the texture maps used.

* Stefan Lisowski, Omron Software**Kaoru Hiramatsu, NTT Communication
Science Laboratories

On the right you see the output of the 3DML
plug-in. You can follow it’s features to the middle diagram where a square of letters matches
the courtyard walls and a single letter represents
the corner tower top. Zooming in to one level ofthe 3DML text map, you can follow the letter“T” to the block definition part of the .3DML
file. There you see that it has two different textures associated with a type # (solid) block.

3DML Interface

External Internet Web Sites

MS Agent

Back End
Database Server
PostgreSQL
Title,X,Y,URL,Key
word

Local Photos and Web
Based Information

Chat
FIGURE B, Digital City Bus Tourat high resolution to provide a detail view. The remaining photographs
were processed, cropped and compressed to allow them to be mapped
onto 3D blocks. A map of each area was used to create the 3DML layered letter-block maps, and keep them accurately relating to physicalreality. 3D cubes, blocks, ramps and 2D planes were all used as a skeleton to lay the textures on.
During this initial prototyping phase we have been streamlining thebuilding process and writing documentation for user construction within Digital City Kyoto. Citizens will be able to build community by constructing pieces of the city themselves. The model here is not unlike themodel that brought success to the web with HTML, and the model used
for individuals in Digital Amsterdam [2], MUDs, MOOs and MUCKs(for more MUD information see Mud.Com [3]). Essential in laying thegroundwork for a large and thriving digital city, we intend to avoid topheavy construction, and count on many different people to help us keep
the city sustainable and current. High school students, college students,and residents of the area can provide a huge amount of development
and creative energy to this city. We plan to enable communication
through various channels, such as newsgroups, chat and email.
WWW Information Access
There already are many web sites in existence pertaining to one part orother of the city of Kyoto. By sending a web crawling robot searchingfor appropriate sites, and by making personal connections with individuals, we’ve collected a set of information that represents Kyoto on
the web.
We are now building a database that allows access to this information.
The 3D component (and other interfaces, such as a 2D java map underdevelopment) will rely on this back-end database built in the object/
relational system of PostgreSQL. The database will contain X Y information and URL information for both maps to tie into. With either map
representation, users will click URLs associated with a the specificarea of Kyoto they’re examining. People can link to train schedules,
business schedules, catalogs, historical information, maps, and the vastarray of other resources available on the web.
Links to high resolution graphic details and pre-programmed Microsoft
agent commentary are currently available throughout the 3D site. We
also have a link to a live video camera in the Shijo Kawaramachi areathat provides a real time window into Kyoto.
Digital Bus TourWe are constructing an agent-guided group chat tour of Digital City
Kyoto. A Microsoft Agent guide bird gives tours through the 3D representation of Nijo castle, and along the active streets of Shijo andKawaramachi. Participants in the tours can talk with one another about

their experience in a I-chat window. The agent uses web push technology to move the entire tour from one spot in the tour to another. Once
moved to a spot, participants can walk around by themselves in the 3D
world, talk among themselves, and listen to the guide bird give historical information, trivia and practical information. Clicking on somefeatures displays high resolution photographs with Agent commentaryand text information. External web sites giving further details can belaunched in another browser window as well. We hope this tour willencourage communication among visitors and encourage further use of
the digital city’s resources. See Figure B.
Conclusion
The Open Laboratory Digital City project is a three year venture toattempt to construct a next generation digital city. The first version ofDigital City Kyoto will be completed by the end of the project’s firstyear, September 1999.
Digital City Kyoto contains a new vision of building a digital city on
the net. Digital City Kyoto is a place to collect and share information,a place to build community, and a place where information can bebrowsed from many interfaces: a 2D map, a 3D interface, and/ or listened to from a personable digital agent. DCK is designed to resist
stagnation; citizens of the city will be encouraged to continually add
new information. We envision a growing and changing place, which
serves residents in the actual city as well as real or digital visitors tothe city.
In the future, our hope is to add more live sensor data from the city ofKyoto. For example the City of Kyoto tracks by computer the locationsof all of the busses on the streets there. Also for the future, we plan on
integrating continued web crawls will weed out old internet URLs andadd new ones. Finally, this must be a friendly place for communication
among city residents and visitors.
Acknowledgements
Thanks to Katherine Isbister of NTT, Toru Ishida of Kyoto University
for extensive assistance on this paper. Thanks to Jun-ichi Akahani ofNTT for making the Open Lab a reality. Thanks to Omron Software for
their support.
References
1. Jane Jacobs, The Death and Life of Great American Cities
2. Digital Amsterdam http://www.dds.nl/kaart/
3. Mud.com http://www.mud.com/astromud/members/info/faq.html
4. Eric Raymond, The Cathedral and the Bazaar
http://www.tuxedo.org/~esr/writings/cathedral-bazaar/.
5. Toru Ishida, Communtity Computing