Interactive Generator of Virtual Baroque Dances for Interactive Theatres Maria A. Alberti, Maresa Bertolo, Daniele Marini, Emanuele Genuizzi, Paola Trapani° Dipartimento Scienze Informazione Università degli Studi di Milano Via Comelico 39 20135 Milano, Italy ph. +39 (0) 2 55006 307 [alberti | marini]@dsi.unimi.it, maresa@iol.it, genuizzi@lascala.milano.it ° DiTEC, Politecnico di Milano Piazza Leonardo da Vinci 32 20133 Milano, Italy trapani@giotto.usr.dsi.unimi.it 1. The Interactive Theatre Project The Interactive Theatre is a communication project, experiencing web technologies and virtual reality, to introduce the Teatro alla Scala in Milano to the net audience. Internet launches the challenge of an open theatre, distributed over the territory and the entire social body. This is particularly relevant for a classical theatre, traditionally conceived as a closed space, both physically and socially. The Interactive Theatre encompasses three applications: the web site of the theatre, LaScalaWeb; the 3D reconstruction and the Baroque Dance Project. The project aims at improving the quality of engagement in users, promoting an active behaviour and triggering involvement. To achieve this goal, we integrated many technologies: besides text, images, video, audio and voice, we adopted motion capture, QuickTimeVR, VRML 2.0, JavaScript and CGI [1], [2]. LaScalaWeb [3] provides a multimedia presentation of the theatre and the season, access to the theatre database with data since 1951, news from the press office, biographies of artists, mailboxes, ticket office information, news about audits and a virtual shop. A section is devoted to the virtual visit; it is based on several integrated media: text, audio, still images, voice, providing clues on the QTVR nodes, and VRML modules. Only a light version of the complete VRML application is available through the web site. The 3D reconstruction of Teatro alla Scala shows the building outside and inside, the stage and the backstage which can be explored by users, providing an original view of the theatre machina, and it is augmented by simulation: the sounds of instruments being tuned, the dimming of the lights, the curtains being raised give the emotion of the onset of the performance; moreover the movements of the scenes are reconstructed and can be explored providing an experience different from the actual one. The opera Armide by C.W. Gluck (1714-1787) is our case study. The history of the theatre is documented by the original drawings of the architect G. Piermarini (1731-1808) which have also been used as textures in the 3D model in VRML to return a suggestion of the old theatre. QTVR is well suited to give a synthetic view of a complex environment. Being based on image rendering, this technique conveys a realistic impression of the environment but also limits the perception of the structural complexity of the real space. On the other hand VRML, even in the case when photos are mapped on the surfaces, returns a somewhat artificial effect. The VRML models, on the other hand, can be more interactive than QTVR and in particular animation can be programmed. The Interactive Theatre also stages performances by virtual dancers. A dummy on a stage, located in an ideal theatre, performs baroque choreographs, that can be interactively defined in an editor and executed [4]. The dummy’s movements, modelled with motion capture technique, are synchronised on the music score in MIDI format. In our research, after the first, and most obvious, approach of naturalistic mimicry in simulation we are now looking at more abstract ways of providing information. We believe that users’ engagement is not only function of the similarity to reality (iconicity) but that it also depends on users' typology and on the right mixture of meaningful focused elements and the shadowed ones. In particular we note that users' consensus and emotional adhesion often follows the iconicity degree in low-level competence or occasional users. 2. The Baroque Dance Project The Baroque Dance Project, part of the Interactive Theatre, is a web based interactive tool to define and explore baroque choreographies which can be used for education or for a creative approach to the dance. The project was developed in many phases. At first the Baroque Dance language has been analised and a formal description has been provided, in order to describe well formed sequences of legal dance steps. Subsequently a library of elementary dance steps has been implemented. To this aim we have captured the motion of a professional dancer