Virtual Heritage System: Modeling, Database & Presentation Yong-Moo Kwon, Ig-Jae Kim, Sang Chul Ahn, Heedong Ko, Hyoung-Gon Kim #39-1 hawalgog-dong Sungbukku, Imaging Media Research Center, Korea Institute of Science & Technology, Seoul 136-791, Korea
[email protected] Abstract. This paper addresses three research issues for virtual heritage system, 3D modeling, 3D media asset database management, and interactive presentation through networks. We first show an overview of our virtual heritage system. Then, our approaches on each research issue are introduced. We develop 3D modeling environment using both of two emerging techniques, i.e., image-based 3D modeling and 3D laser scanning-based 3D modeling techniques. Each technique captures range data of 3D objects using 3D input devices and uses 3D mesh modeling scheme. Our test results from both of these trials are shown. One of the important tasks for virtual heritage system is how to manage the various kinds of cultural heritage assets. For this goal, our approach for an asset management is descibed, which includes the system configuration and asset creation method. Finally, we address how to present virtual heritages. Here, we show two approaches, web-based and virtual reality theater-based system. We also address the networking issues for transcontinental cutural heritage exchange and our future plan for 3D cyber museum through Trans-Eurasia Information Network.
1. Introduction Virtual heritage has become increasingly important in the conservation, preservation, and interpretation of our cultural and natural history. Rapid advances in digital technologies in recent years offer virtual heritage new direction [1]. Especially, new media technologies, from 3D media technology to virtual reality, are very promising ones expected to satisfy heritage representation such as the naturalness, the sensation of depth and realism [2-3]. This paper addresses three research issues of virtual heritage system. Our main concern is how to create, manage and present virtual heritages. For this goal, we first address the 3D modeling techniques and show some illustrative examples. Then, we describe an approach of 3D model DB construction. Finally, we show our two presentation schemes of 3D cultural heritages, i.e., web-based and virtual reality theater-based virtual heritage systems. Section 2 introduces an overview of our virtual heritage system. Section 3 presents 3D modeling techniques and some trials. Section 4 describes the implementation of 3D cultural heritage asset management system. Section 5 shows the presentation schemes of 3D cultural heritages. Section 6 describes our future work plan to develop 3D cyber museum through Trans-Eurasia Information Network 2. Virtual heritage system We design virtual heritage system of which main goal is the service of virtual heritage through network. The system focuses on the following four issues: - Automatic and semi-automatic generation of 3D model - Systematic asset management of 3D models using DBMS - Creation of new 3D contents through authoring - Service of virtual heritage through network
Fig. 1 shows the overview of the designed system. Virtual Heritage Service
3D Modeling
3D Media Asset Management Server
3D Contents Authoring
Fig. 1. Overview of virtual heritage system We also design the augmented reality virtual heritage system which can provide the capabilities of interactive 3D model browsing and augmentation of virtual heritage using text and image for enhancing its historical meanings of heritrage within 3D virtual space. 3. Modeling 3.1 Image based 3D modeling 3.1.1 Off-line approach By using single camera and robot arm, we capture multiview images while controlling the image capture position. Then, the disparity for object is analyzed to extract range information. For the disparity extraction, we develop MR-MBS technique[4] of which main idea is the application of multiresolution technique to MBS. The application of the multiresolution technique to stereo matching diminishes the effect of the boundary overreach in depth map, since the matching through the multiresolution gets the effect as various window sizes. Another important effect of multiresolution technique is that the proposed MR-MBS method gets matching process faster than MBS method. After extracting the disparity map, the object is segmented using the disparity histogram in assumption that the background is far from the object. Fig. 2 shows an example of image-based 3D modeling scheme.
Fig. 2 image-based 3D modeling (off-line)
3.1.2 On-line approach The Triclops color stereo vision system[5] provides real-time range images using stereo computer vision technology. The system is composed of a calibrated three color camera module connected to a PC with machine vision software. The system is based on MBS technique. Here, we extend the system by using object segmentation scheme. 3.2 Laser scanning based 3D modeling The computer vision researches have long studied the problem of determining the shape of an object from a set of photographs. One of the common forms of active range sensing for 3D modeling is optical triangulation[6]. One example of this technique is well-known laser scanning technique. The fundamental principle is as follows: The laser stripe is casted onto the surface of the object, which is then captured by the conventional CCD camera. Then the range information can be captured by analyzing the captured pattern of the laser stripe. Thus each captured image gives us a range profile and sweeping the light over the surface of the object, we can capture its shape. Here, we apply the laser scanning scheme for 3D modeling of Korea cultural heritage. We use Vivid 700 laser scanner made by Minolta Co. For 3D modeling from point clouds of laser scanning, we use RapidForm[7] that has functions of polygon generation using triangulation, and registration & merge of polygon models. Fig. 3 shows the merge operation of polygon models.
Fig. 3 3D partial model merging process 4. Database One of the important issue of virtual heritage system is how to manage virtual heritage assests. Based on networked storage system, asset management system can be implemented while supporting the various kinds of file formats of virtual heritages. Using eXcelon XML data server[8], we construct a virtual heriatge database system, which can provide the service of 3D models through WWW. The major reason for selecting eXcleon XML data server is the compability of file exchange among heterogeneous systems. We design XML schema for describing various features of heritage as attributes and encapsulting various kinds of 3D file formats within XML file consistently. Fig. 4 shows the configuration of virtual heritage asset management system. The eXcelon data server comprises eXcelon Studio, eXcelon Explorer, eXcelon Manager. As shown in Fig. 5, we first design the schema for 3D models and the corresponding textures using eXcelon Studio. Then, XML file for 3D models are created while inserting the data of 3D models
using eXcelon Explorer. The inserted 3D model data is managed by ObjectStore DB engine that provides the function of insert, delete, and update. By using XQL, we also provide the query of 3D models. SGI OnyxII
HTML
Internet Intenet Explorer
XQL Web Server
eXcelon Data Server (ObjectStore)
XML
Fig. 4 Configuration of XML-based virtual heritage asset management system
xmlstore create
eXcelon Explorer
xml schema create
eXcelon Studio
xml data insert
xml data file created
Fig. 5 Asset creation process
5. Presentation 5.1 Web service of 3D models We develop asp file for servicing 3D models through WWW. We provide the search scheme for 3D models using keyword. Fig. 6 shows a schema of search program. Fig. 7 shows an home page of a heritage service (http://culture.kist.re.kr). As shown in two figures, the search can be performed through technology, category and media type. We also provide 3D model tour scheme based on image-map. Our system provides a scheme for making a schedule of tour course by clicking cultural heritage icon sequentially. When the schedule is finalized, one can see 3D models sequentially as scheduled by clicking tour button. Fig. 8 shows the 3D tour scheme using imagemap of Sorabol that is an old capital of Shilla Kingdom of Korea about 1,300 years ago. search_form.asp technology
search_technology.asp
category
search_category.asp
mediatype
search_mediatype.asp
Media type
wrl_view.asp
video.asp
mov_view.asp
3D VRML
Video
Quick Time VR (Panorama Image)
Fig. 6. media serach scheme
Fig. 7. Media search window (http://culture.kist.re.kr)
Fig. 8 Map-based virtual heritage tour window 5.2 VR theater-based virtual heritage service We implement 3D virtual reality theater for Kyungju World Culture EXPO 2001, in which we present cultural heritage contents that introduce Sorabol city of Shilla kingdom about 1,300 years ago. Our "3D virtual reality theater" is reported at the SGI web site http://www.sgi.com/features/2001/feb/kyongju/. Fig. 9 shows overview of our virtual reality theater.
27m x 8m screen
651-seat Cyber Image Hall Keypad User Interaction fragrance
3 D Sound (8 Channel Surround)
Super -high resolution Projectors (6 Channels)
Fig. 9 Virtual reality theater
This virtual reality theater is composed of 6-pipeline ONYX-2 computer, 6 Barco projectors with edge blending system for 3 stereoscopic passive type display channels (total 6 channels), wide screen of 27m x 7 m, 8 channel 3D sound system, keypad based interaction system, fragrance control systems. Fig. 10 shows a rendering of Main Buddha of Sukkulam of Kyungju which is one of Unesco cultural heritages and shown in virtual reality theater.
Fig. 10 Rendering of 3D Main Buddha of Sukkulam 6. Future work plan We aim to establish a networked virtual reality infrastructure and content development for museums and cyber theater for mutual exchange of digital cultural and natural heritage. Asian and European partners are participating for transcontinental shared immersive experience in a global scale using high bandwith Trans Eurasia Information Network. Fig. 11 shows research cooperations with Asian and European partners for 3D cyber museum service.
Fig. 11 Research cooperation with Asian and European partners
Our future work plan includes the followings: ▷ Content development of digital cultural and natural heritage ▷ Establishment of a networked virtual reality infrastructure ▷ Shared virtual reality experiences through TEIN. ▷ Remote guided virtual environment Fig. 12 shows our network coordination plan for 3D cyber museum service. First, KIST located at Seoul is connected to Kyungju Virtual Reality Theater with 155 Mbps ATM through KOREN (Korea Research Network). Then KOREN is connected to TEN-155 (TransEuropean Network) for establishing TEIN.
TEN-155
Seoul
KOREN Daejon
APII(APAN)
Daegu
Kyungju
Kwangju Busan
Fig. 12. Network coordination from Seoul to Kyungju, Asia and Europe Fig. 13 shows the plan of Korea-Europe research network and expected network construction.
Fig. 13. Korea-Europe research network and expecteed construction
We will establish shared network virtual environment between Aisa and Europe through TEIN, especially for 3D cyber museum. We will support three types of 3D cyber museum, i.e, VR theater, CAVE, web-based system. One of our goals is to develop remote guided virtual environment by integrating virtual studio technology and immersive virtual environment technology. As shown in Fig. 14, virtual heritage contents of Korea can be explained for European clients in Europe within an immersive virtual environment using the synthesis of streaming video and virtual heritage while Korean historical expert explains about the contents in Korea, of which MPEG-2 streaming video is transmitted to Europe through TEIN.
* VR Theater * CAVE * Web
* 3D Contents * Real Video with chroma key * 3D Model/Conetnts DB
Fig. 14. Concept of remote gudied virtual heritage system 7. Conclusion In this paper, we address three research issues of virtual heritage system and introduce our virtual heritage system of which main goal is the service of various types of 3D models and contents of cultural and natural heritages. We first present our 3D modeling schemes based on computer vision scheme and laser scanning scheme. Second, we show our approach for the management of cultural heritage assets. Finally, we introduce our web-based 3D model system (http://culture.kist.re.kr) and virtual reality theater for immersive and interactive cultural heritage presentation. We also describe our future work plan to develop 3D cyber museum through Trans-Eurasia Information Network References [1] S. T. Refsland, T. Ojika, A. Addison, R. Stone, “Virtual heritage: breathing new life into our ancient past,” IEEE Multimedia, Vol. 7, No. 2, 2000. [2] Applications of Computer Vision to Computer Graphics, Computer Graphics, vol. 33, no. 4, Nov. 1999. [3] Takeo Kannade, and Peter Tander, "Virtualized Reality: Constructing Virtual Worlds from Real Scenes," IEEE MultiMedia 4, pp. 34-37, 1997. [4] Y.-M. Kwon et al., "Multiresolution approach to depth extraction for arbitrary view synthesis," Proceedings of 3D Image Conference '98, Tokyo, Japan, pp. 135-140, July 1-2, 1998. [5] Users manual and command reference, Triclops stereo vision system. [6] B. Curless, "From Range Scans to 3D Models," Computer Graphics, vol. 33, no. 4, pp. 38-41, Nov., 1999. [7] RapidForm, www.rapidform.com. [8] eXcelon XML Data Server, www.odi.com.
