Technology used to realise construction 3

Several technologies have been incorporated and developed as part of the RIMM project..

Sensors
Using wireless, wearable technology, a set of sensors have been developed to allow the performer to control sound generation, audio mixing and spatialisation, real-time signal processing and graphics. These sensors include actuators controlled by toe pressure, accelerometers, infra-red video tracking and a digital compass. This system was designed to capture performance gestures without interfering with the performers technique and posture following a video analysis of the performers movements. These sensors were interfaced via a PIC microcontroller to a customised radio transmission system to provide wireless RS-232 communication with the main computer systems.

A Real-Time Graphics Engine
Written using the OpenGL Application Programming Interface, this engine runs on a Silicon Graphics O2 workstation and communicates with the rest of the system via UDP network sockets.

A Multiprocessor Configuration of jMax for Real-Time Multiple Media Content Generation using Surround Sound
A series of intercommunicating jMax patches have been developed to perform in real-time on a Silicon Graphics Origin 2000 computer. These patches include 9 Spat.~room simulators working together to localise multipe sound matierials. The intensive computation of real-time room simulation required the use of multiple R10000 processors. Multiple 8 channel audio streams and control information is communicated between the instances of jMax using UNIX shared memory devices and UDP sockets to take advantage of the high inter-processor bandwidth of the Origin 2000. The final soundfield is decoded using an 8 channel cubic decoder (customised by IRCAM for the RIMM project) and reproduced over an 8 speaker ambisonic array.

construction 3 system overview