Metadata Enhanced 3D Content Search for Real- Time Visualization of 3D Digital Assets Alexia Kolosova STARC Department The Cyprus Institute Nicosia, Cyprus a.kolosova@cyi.ac.cy Sorin Hermon STARC Department The Cyprus Institute Nicosia, Cyprus s.hermon@cyi.ac.cy Abstract— This paper presents a virtual 3D repository that incorporates user activity to its content selection procedures, in order to deliver personalized results on a real-time basis. This is achieved by embedding a metadata-based search engine to the repository interface in order to facilitate object discovery. This search mechanism takes advantage of the rich metadata describing the 3D content stored in our repository. Several algorithms are used to extract information from the metadata files in order to provide the search options, as well as the information resulting from the user selections. The main challenges we have to address concern the algorithmic efficiency, as well as the relevance of results related to user requirements. Keywords— virtual m useum; 3 D r epository; m etadata; c ontent search Introduction During t he l ast de cade, m useums a nd i nstitutions f rom a ll over t he w orld ha ve de veloped t he ne ed for a s trong o nline presence t hat woul d pr ovide no n-physical access t o cu ltural heritage content – i.e. the creation of a virtual museum[1]. This newfound approach derived from the fact that several museums lack ex hibition s pace, w hile t here i s al so t he n eed t o en sure proper preservation of archaeological artifacts. Along with the use of c ost-effective te chnological t ools a nd methods t hat are widely a ccessible nowa days, t he di stribution a nd demonstration of di gital cultural he ritage c ontent w as facilitated acr oss t he Web. H owever, several l imitations s till exist that hold t hese a pplications ba ck from t heir great potential. A main problem is that many of these applications are not user-oriented, m eaning t hat they do not i ncorporate a ny us er functionality or interface mechanisms to help users select what content t hey w ant t o s ee. Thus, t he u sers interact m ore passively by s imply na vigating i nto t he vi rtual s paces, sometimes f orcing t hemselves t o read information about objects that are not so appealing to them. Furthermore, as time goes by cultural heritage gets destroyed, so the need for proper preservation of t he cu ltural h eritage o bjects i ncreases. Researchers, ar chaeologists o r ed ucators m ay f ace t he n eed t o study 3D content virtually in the future, so they should have the opportunity t o do s o. F rom this pe rspective, a us er-oriented search interface would be of great importance to this category of users, as they would have the control over what they choose to study and also select it by their terms of search, e.g. based on a specific chronology. This information is already provided in the rich descriptive metadata f iles t hat ar e s tored i n o ur database. M etadata nowadays are considered to be one of the most powerful ways of gathering and distributing self-describing information about digital c ontent [ 2]. T hus, i t is im portant to t ake a dvantage of them i n o rder t o f acilitate object d iscovery. A lso, m etadata schemas are continuously altered in order to correspond to the increasing needs of the context area that they are applied to. A dynamic metadata-based search would profit from this, as any alterations woul d p ossibly mean f urther e xtension a nd optimization of the search mechanisms. In t his pa per we a im t o s how t hat t he i ntegration o f a metadata-based search engine to the interface o f a 3D repository could help users obtain meaningful results according to their interests, thus saving time and effort in searching. We study t he ef ficiency an d ef fectiveness of t he a lgorithms b eing used. A dynamic real-time search mechanism can tolerate little to m inimum delay, s o t he a lgorithms applied should be efficient. Finally, we ove rview t he r esults obt ained i n s everal different search cases in order to study the degree of correlation with their corresponding optimal result sets. The r emainder of t his paper i s s tructured a s follows. In Section 1 we give an overview of the work previously done in this field. A brief description of the interface layout is given in Section 2. I n S ection 3 we give a d escription o f t he process followed by t he u sers when t hey i nteract with t he i nterface. More technical details that concern the system architecture are presented i n S ection 4. Later, i n S ection 5 w e describe t he algorithms used for the data retrieval and their limitations. An overview of the results obtained by several sample search cases is p resented i n S ection 6 . Finally, in S ection 7 we p resent t he conclusions, limitations and future work. I. PREVIOUS WORK Several a pplications ha ve be en pr oposed i n or der t o pr omote the i dea o f a v irtual museum. T hese v ary b etween s imple interfaces that exhibit 2D [3, 4] and 3D [5] content, and more complex ones that incorporate virtual [6] and augmented reality environments [ 7] with na vigation possibilities. Other p rojects exist that provide search mechanisms on t heir interfaces [8] in order to retrieve metadata for content demonstration purposes. Some of t hem us e metadata not onl y t o de scribe, but a lso t o browse through the digital collections [9]. These studies mainly refer to 2D content. 978-1-4799-3169-9/13/$31.00 ©2013 IEEE 173