Stylesheet Transformations for Interactive Visualization: Towards a Web3D Chemistry Curricula Nicholas F. Polys Department of Computer Science Virginia Polytechnic Institute and State University (Virginia Tech) US 540.961.2951 npolys@vt.edu ABSTRACT Recent Standards specifications offer important but underemployed techniques to maximize access-to and distribution-of information for real-time 3D visualization over the web. This paper describes and evaluates such techniques to transform structured data such as Chemical Markup Language (CML) to different forms and contexts for Web3D delivery using Extensible Stylesheet Transformations (XSLT), Extensible 3D (X3D), and VRML97. Standards design approaches offer a number of advantages: data durability, data interoperability, and an ecology of tools to be deployed for production and delivery. As we demonstrate, these techniques allow developers to port data between multiple representations and formats, to leverage the separation of the presentation (reference) from the content (referent), and the ability to define ‘high-level’ markup tags for application-specific needs. By defining a set of XSL Transformations, we are able to generate multiple views and interaction schemes with the same data set; each one ‘personalized’ for different applications and different levels of expertise. Categories and Subject Descriptors D.3.3 [Programming Languages]: X3D, VRML, XML, XSLT, DOM, CML, Java General Terms Standardization, Languages, Design, Keywords Information Visualization, Interactive 3D Graphics, Molecular Chemistry, Education 1. INTRODUCTION International standards organizations serve the computing community by developing and specifying open platforms for digital data exchange- they provide the evolving nexus for Integration and Interoperability. By building to industry standards, organizations can lower their costs for software and data integration, maximize their data re-use and all the while guarantee author reliability and user access beyond market and political vagaries. Such internationally recognized standards are manifested as widely deployed web technologies such as HTML, SGML, and the XML family produced by the World Wide Web Consortium (W3C) [18] and Virtual Reality Modeling Language (VRML) and Extensible 3D (X3D) produced by the Web3D Consortium (Web3DC) [14]. This paper examines important but underemployed techniques for 3 or 4-dimensional visualization of XML data with X3D and VRML. Through diligent and cooperative work, the X3D Task Group and the W3C have converged on an XML encoding for interactive 3D scenegraphs – X3D. X3D is a componentized and improved successor to VRML97 for describing and programming Web3D virtual environments. By using the XML encoding of X3D, developers can leverage the entire XML family of technologies and get a suite of tools for data portability as XML is founded on the distinction between content and presentation [7, 9, 15]. We believe that the full impact of the convergence between Web3D and XML is not yet fully understood, and intend this project to show the power of open standards and technologies. In this project, multiple visualizations of the same data are be achieved through Extensible Stylesheet Transformations (XSLT) technologies [18]. Using a structured data representation from the Chemical Engineering community, Chemical Markup Language (CML) [3], we will demonstrate a set of web-ready methodologies for processing, publication and display that can be applied to any XML dialect or structured data source. 1.1 Extensible Markup Language (XML) The World Wide Web Consortium’s (W3C) metalanguage codification of XML has opened new and powerful opportunities for information visualization as a host of structured data can now be transformed and/or repurposed for multiple presentation formats and interaction venues. XML is a textual format for the interchange of structured data between applications [18, 7, 15]. The great advantage of XML is that it provides a structured data representation built for the purpose of separating content from presentation. This allows the advantage of manipulating and transforming content independently of its display. It also dramatically reduces development and maintenance costs by allowing easy integration of legacy data to a single data representation which can be presented in multiple contexts or forms depending on the needs of the viewer (a.k.a. the client). Data thus becomes ‘portable’ and different formats may be delivered and presented (styled) according to the application’s needs. Another important aspect of XML is the tools that it provides: the DTD and Schema. The Document Type Definitions (DTD) defines ‘valid’ or ‘legal’ document structure according to the syntax and hierarchy of its elements. The Schema specifies data types and allowable expressions for element’s content and . Copyright © 2003 by the Association for Computing Machinery, Inc. 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