A Collaborative Sound Installation Using Projected Geometry and Spatial Interaction

Hani Alshamrani; Sam Ferguson; Andrew Johnston

A Collaborative Sound Installation Using Projected Geometry and Spatial Interaction
Image credit: Hani Alshamrani; Sam Ferguson; Andrew Johnston

Abstract:

We present a collaborative audio visual installation where up to four performers create music by using portable handheld projection systems called BeamPods to project shapes onto a projection surface. A ceiling-mounted camera tracks the projections and extracts shape identity and geometric cues, including position, scale, and distortion, to drive real-time sound synthesis. The projected shape acts as a visible, portable musical voice, allowing performers to see their own contribution and coordinate with others in a shared visual field. The installation is structured around five Spatial Interaction Points (SIPs), discrete floor positions, that define discrete interaction states, while continuous geometric features support expressive control. When performers converge in the same region, the shared pitch mapping makes their contributions converge musically, supporting coordination through spatial negotiation. Designed for walk-up participation in public or workshop settings, the system supports collaborative music-making without prior musical training. This paper reports the design rationale, interaction model, and implementation of this system.