NeXTSTEP Graphical Interface to Control Spatialization Systems


Session Title:

  • Interactive and Intermedia Software System Design

Presentation Title:

  • NeXTSTEP Graphical Interface to Control Spatialization Systems



  • We present here the last developments concerning the graphical user interfaces we are designing to control sound instruments in the new FTS Client/Server architecture or through MIDI. In particular, MoveInSpace, the movement generator interface for sound spatialization significantly improved since our last publications (JIM96 and ICMC96 proceedings).
    This interface is developed under object-oriented and real time concepts. It constitutes a graphical tool to define tridimensional trajectories, independently of the spatialization system. The composer can choose predefined trajectories or define new 3D trajectories with the mouse or with a data glove. From one particular trajectory, several other trajectories forming a class can be derived thanks to different transformation methods: translation, scaling, speed modification, moving, adding or removing points.These trajectories are saved by pressing the record button and are played back by pressing the forward or backward play buttons. During the saving process, an icon representing the trajectory is created. A set of classical command buttons—Stop, Play, Pause, Return To Zero, Loop — is also available. It is moreover possible to correlate the spatial movement with parameters of the sound (e.g.:frequency, amplitude, filter parameter,… ). Actually, the user can define other functions, in the way he defines the altitude curve.The composer can explore the resources of spatiomorphological transformations, correlating sound spatialization to other sound processing, like pitch shifting, dynamic filtering,… As a matter of fact, MovelnSpace becomes a general multi-controller. It allows to simultaneously control the dynamic evolution of a large set of parameters and can be useful to pilot sound processing programs that require the definition of many parameters. Different parameters concerning size and shape of the room where the sound is spatialized are easily specified and visually controlled by the user, such as the real and the virtual dimensions of the room, the number, the position and the size of the loudspeakers. We also introduced the interpolation concepts in this inter face.The user will be able to place and size interpolation spheres in space. Each sphere represents a set of parameters and a resulting set will be calculated by interpolation, depending on the position of a point moving in this space. We are testing this tool on different spatialization system : on an acousmonium controlled by VCA, on a quadraphonic spatialization system and on the Ircam “Spatialisateur.”This interface constitutes an efficient graphical tool to easily control spatialization instruments or, in general, any sound processing programs that require the simultaneous definition of many parameters.