Extracting Geometry from Digital Models in a Cultural Heritage Digital Library Thomas L. Milbank Perseus Project, Tufts University

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 as immutable objects... »leads to in toto retrieval »impacts library search results

Paradigm: a search for column capitals

Models as texts Digital model of Boston , 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 “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 ”... … include sub-object  instantiations 

 Results of search for “Boston ”... … 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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