Extracting Geometry from Digital Modelsin a Cultural Heritage Digital Library

Thomas L. Milbank

Perseus Project, Tufts Universitytmilbank@perseus.tufts.edu

Introduction

Digital libraries can …» disseminate objects “as is” through cataloged metadata

» disseminate objects customized to the user through automated processes

Models and libraries

The treatment of models asimmutable objects ...

» leads to in toto retrieval

» impacts library search results

Paradigm: a search for column capitals

Models as texts

Digital model of Boston 07.1002, a relief from tomb G 2110 at Giza, ...

rendered in an image

rendered in XML

The Perseus document manager & X3D

X3D encoding of tomb G 2110

The Boston 07.1002 “Transform”

is mapped and indexed as “object”

Index of elements/mappings

The Perseus document manager & X3D

• PDM references the index

• PDM opens the model and reads the sub-object(s)

• PDM processes the X3D fragment and outputs VRML for display in an HTML page

Results of search for “Boston 07.1002” ...

… include sub-object instantiations

Implications for model design

Need for well-defined and well-named geometry» Object-oriented modeling is suitable natively

» Layer-oriented modeling is suitable with forethought

Conclusions

• XML processing techniques …» can be applied to digital models successfully

» facilitate the identification of geometry incorporated into larger constructs

» enable the extraction of sub-object geometry

• The application of XML processing techniques establishes a framework for the integration of models with additional library services

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Thomas L. MilbankPerseus Project, Tufts University

tmilbank@perseus.tufts.edu