The OVC-3D is not a single instrument, but rather a system that allows many different instruments to be designed and played. It can accept multiple types of hardware devices as inputs and create an unlimited range of synthesizers that use these inputs in unique ways to generate images. We had observed the efforts of many people to create new types of audio musical instruments and noted how each one was played in a different way. Users would abandon an instrument for a newer toy long before they ever really mastered the art of playing it. Instead, we wanted to emulate the success of keyboard synthesizers: they can create different sounds, but the motor learning from practicing one instrument is largely reusable on the next. Our goal was to develop a general way of playing an instrument that could be applied to many different types of visual synthesizers. Developers can create new and innovative instruments that artists can quickly learn how to play.
Our basic approach uses the two hands in a complementary fashion, in the same way for example that a guitar uses the pick hand to trigger the sonic events and the fret hand to control what happens in response to these triggers. The hand controllers provide precise tracking of hand position in 6 axes (3 position + 3 direction) plus finger controls including sliders and buttons. The strategy is to use the motion and finger controls in consistent ways that can apply to a variety of instruments. The types of functions performed by these controls are different for the left and right hands.
The right hand uses the fingers to trigger events, controlling the amounts of different types of energy injected into the scene. The type of emission varies according to the instrument design, such as an explosive bursts, delicate symmetric streams, or sparkling cloud. The artist can vary the amount of each emission, triggering and blending them into a constantly evolving expression. The position and orientation of the hand are used to control movement. This might set a single position of a free moving dancer or use reflections to form complex patterns so that the artist’s movements define a constantly evolving shape more than a single dancer.
The left hand controls the behavior of the events that are triggered by the right hand. We convert the hand position and orientation into six high-level controls that are implemented in the design of each synthesizer following a universal strategy. A synthesizer may be programmed so that a single control variable affects the parameters of many low level nodes generating the visual output. While this mapping is unique for every synthesizer, the common high-level strategy makes it easy for an artist to learn to play a different synthesizer. The six axes are controlled independently and simultaneously. While a novice might occasionally modify individual controls, a practiced expert continuously adjusts multiple different aspects of the system with complex, multidimensional gestures.
We also use foot pedals to control output levels in a manner similar to the use of volume pedals with audio instruments. When multiple pedals are available, the various synthesizer elements can be divided into groups, each controlled by a different pedal.