@inproceedings{HerderCohen1997, author = {Herder, Jens and Cohen, Michael}, title = {Enhancing Perspicuity of Objects in Virtual Reality Environments}, series = {Proceedings, Second International Conference on Cognitive Technology}, booktitle = {Proceedings, Second International Conference on Cognitive Technology}, editor = {Gorayska, Barbara and Nehaniv, Chrystopher L. and Marsh, Jonathon P.}, publisher = {IEEE}, address = {Los Alamitos}, isbn = {0-8186-8084-9}, pages = {228 -- 237}, year = {1997}, abstract = {In an information-rich Virtual Reality (VR) environment, the user is immersed in a world containing many objects providing that information. Given the finite computational resources of any computer system, optimization is required to ensure that the most important information is presented to the user as clearly as possible and in a timely fashion. In particular, what is desired are means whereby the perspicuity of an object may be enhanced when appropriate. An object becomes more perspicuous when the information it provides to the user becomes more readily apparent. Additionally, if a particular object provides high-priority information, it would be advantageous to make that object obtrusive as well as highly perspicuous. An object becomes more obtrusive if it draws attention to itself (or equivalently, if it is hard to ignore). This paper describes a technique whereby objects may dynamically adapt their representation in a user's environment according to a dynamic priority evaluation of the information each object provides. The three components of our approach are: - an information manager that evaluates object information priority, - an enhancement manager that tabulates rendering features associated with increasing object perspicuity and obtrusion as a function of priority, and - a resource manager that assigns available object rendering resources according to features indicated by the enhancement manager for the priority set for each object by the information manager. We consider resources like visual space (pixels), sound spatialization channels (mixels), MIDI/audio channels, and processing power, and discuss our approach applied to different applications. Assigned object rendering features are implemented locally at the object level (e.g., object facing the user using the billboard node in VRML 2.0) or globally, using helper applications (e.g., active spotlights, semi-automatic cameras).}, language = {en} } @article{HerderCohen2002, author = {Herder, Jens and Cohen, Michael}, title = {The Helical Keyboard: Perspectives for Spatial Auditory Displays and Visual Music}, series = {Journal of New Music Research}, volume = {31}, journal = {Journal of New Music Research}, number = {3}, pages = {269 -- 281}, year = {2002}, abstract = {Auditory displays with the ability to dynamically spatialize virtual sound sources under real-time conditions enable advanced applications for art and music. A listener can be deeply immersed while interacting and participating in the experience. We review some of those applications while focusing on the Helical Keyboard project and discussing the required technology. Inspired by the cyclical nature of octaves and helical structure of a scale, a model of a piano-style keyboard was prepared, which was then geometrically warped into a helicoidal configuration, one octave/revolution, pitch mapped to height and chroma. It can be driven by MIDI events, real-time or sequenced, which stream is both synthesized and spatialized by a spatial sound display. The sound of the respective notes is spatialized with respect to sinks, avatars of the human user, by default in the tube of the helix. Alternative coloring schemes can be applied, including a color map compatible with chromastereoptic eyewear. The graphical display animates polygons, interpolating between the notes of a chord across the tube of the helix. Recognition of simple chords allows directionalization of all the notes of a major triad from the position of its musical root. The system is designed to allow, for instance, separate audition of harmony and melody, commonly played by the left and right hands, respectively, on a normal keyboard. Perhaps the most exotic feature of the interface is the ability to fork one{\~A}­s presence, replicating subject instead of object by installing multiple sinks at arbitrary places around a virtual scene so that, for example, harmony and melody can be separately spatialized, using two heads to normalize the octave; such a technique effectively doubles the helix from the perspective of a single listener. Rather than a symmetric arrangement of the individual helices, they are perceptually superimposed in-phase, co-extensively, so that corresponding notes in different registers are at the same azimuth.}, language = {en} } @inproceedings{Herder1997, author = {Herder, Jens}, title = {Tools and widgets for spatial sound authoring}, series = {CompuGraphics ' 97, Sixth International Conference on Computational Graphics and Visualization Techniques: Graphics in the Internet Age, Vilamoura, Portugal}, booktitle = {CompuGraphics ' 97, Sixth International Conference on Computational Graphics and Visualization Techniques: Graphics in the Internet Age, Vilamoura, Portugal}, address = {Portugal}, isbn = {972-8342-02-0}, url = {http://nbn-resolving.de/urn:nbn:de:hbz:due62-opus-896}, pages = {87 -- 95}, year = {1997}, abstract = {Broader use of virtual reality environments and sophisticated animations spawn a need for spatial sound. Until now, spatial sound design has been based very much on experience and trial and error. Most effects are hand-crafted, because good design tools for spatial sound do not exist. This paper discusses spatial sound authoring and its applications, including shared virtual reality environments based on VRML. New utilities introduced by this research are an inspector for sound sources, an interactive resource manager, and a visual soundscape manipulator. The tools are part of a sound spatialization framework and allow a designer/author of multimedia content to monitor and debug sound events. Resource constraints like limited sound spatialization channels can also be simulated.}, language = {en} }