Virtual violin in the digital domain : physical modeling and model-based sound synthesis of violin and its interactive application in virtual environment

Viulun mallintaminen on tunnustettu maailmanlaajuisesti erittäin haasteelliseksi ongelmaksi. Väitöskirjan syntymistä ja tutkimuksessa esitettyjen uusien tekniikoiden kehittämistä ovatkin ohjanneet pitkälle käytännön syyt. On ollut tarve pyrkiä luomaan aiempaa luotettavampia ja todenmukaisempia fysikaalisia malleja, mm. äänisynteesiä varten syntetisaattoreihin ja esimerkiksi mobiililaitteisiin, Jan-Markus Holm kertoo viulun fysikaalista mallintamista käsittelevän väitöstyönsä taustoista.This thesis discusses techniques for physical modeling and model-based sound synthesis of violin, and human-computer interaction in virtual domain. The violin model is considered by means of controlling a virtual violin.The work can be divided into three parts corresponding to 1) computational analysis and synthesis of audio and music, 2) physical modelling and model-based synthesis of musical instruments, especially bowed strings, and 3) virtual techniques of representing, expressing, and controlling of violin. The emphasis of the work is on physical and physics-based modeling, musical signal analysis and synthesis, and expressiveness and virtual reality techniquesin controlling a virtual violin.The first part of the thesis mainly concentrates on computational audio and music analysis as well as synthesis. It also presents general methods of analysis of harmonic signals using different techniques. The second part of the thesis considers linear and particularly nonlinear discrete-time modeling of bowed string instruments, especially the violin. The finite width bowing that is present in every excitation phenomenon of a real string has been integrated into the model. Its simulation has been developed into a computationally feasible structure and it has been demonstrated that the models produce desired effects on the synthetic tones in a desired manner. The controllability over the model is considered, and some general outlines on expressiveness of a violin model are carried out. The third part of the thesis discusses virtual reality techniques inapplication to human-computer interaction of musical instrument models. An overview on the virtual musical instruments and their control is given, after which the focus is placed on gestural and haptic control of violins. Interaction with the violin model in application to a virtual environment is also discussed