Volume 23 (2004), number 1 pp. 25–41 COMPUTER GRAPHICS forum Cultural Heritage Preservation Using Constructive Shape Modeling C. Vilbrandt 1 , G. Pasko 2 , A. Pasko 3,2 , P.-A. Fayolle 1 , T. Vilbrandt 6 , J. R. Goodwin 4 , J. M. Goodwin 5 and T. L. Kunii 2 1 University of Aizu, Department of Computer Software, Aizu-Wakamatsu, Japan 2 IT Institute of Kanazawa Institute of Technology, Tokyo, Japan 3 Hosei University, Department of Digital Media, Tokyo, Japan 4 Director of the Aizu History Project, Los Angeles (CA), USA 5 University of California Los Angeles, Department of Computer Science, Los Angeles (CA), USA 6 myth-works.com, Japan and USA Abstract Issues of digital preservation of shapes and internal structures of historical cultural objects are discussed. An overview of existing approaches to digital preservation related to shape modeling is presented and corresponding problems are considered. We propose a new digital preservation paradigm based on both constructive modeling reflecting the logical structure of the objects and open standards and procedures. Constructive Solid Geometry (CSG) and Function Representation (FRep) are examined and practically applied as mathematical representations producing compressed yet precise data structures, thus providing inter-operability between current and future computer platforms crucial to archiving. Examples of CSG reconstruction of historical temples and FRep modeling of traditional lacquer ware are given. We examine the application of fitting of a parameterized FRep model to a cloud of data points as a step towards automation of the modeling process. Virtual venues for public access to cultural heritage objects including real time interactive simulation of cultural heritage sites over the Web are discussed and illustrated. Keywords: cultural heritage, digital preservation, shape modeling, constructive solid geometry, function represen- tation, implicit surfaces, fitting, virtual environments. ACM CSS: I.3.5 [Computer Graphics]: Computational Geometry and Object Modeling, Boundary representations, Constructive solid geometry (CSG) ∗∗ , Curve, surface, solid, and object representations, Function representation, Modeling packages; I.3.6 [Computer Graphics]: Methodology and Techniques, Graphics data structures and data types, Languages, Standards; I.3.8 [Computer Graphics]: Applications – simulation, digital preservation of cultural heritage 1. Introduction The preservation of cultural heritage objects through the use of computer modeling techniques has attracted considerable attention in computer graphics, geometric modeling, and virtual reality communities [3]. This is a particularly im- portant issue in the realm of cultural heritage, since objects may be easily demolished, as the recent destruction of the Buddha images in Afghanistan has powerfully demonstrated. The archiving of digital data or digital models is possible, in part, because digital models can be digitally reproduced any number of times without degradation at very little cost. This allows for any number of exact digital duplicates of digitally modeled objects to be stored in various locations, thus providing both public access and security; such is not possible with physical objects. We review the application of computer technology and its advantages for cultural heritage preservation. c  The Eurographics Association and Blackwell Publishing Ltd 2004. Published by Blackwell Publishing, 9600 Garsington Road, Oxford OX4 2DQ, UK and 350 Main Street, Malden, MA 02148, USA. 25 Submitted November 2002 Revised April 2003 Accepted December 2003