NIME 2025 gRAinyCloud

Collaborative co-located Mixed Reality musical instruments com-
bine some of the expressive opportunities of 3D interaction and
communication and cooperation of physical multi-user instru-
ments. However in existing instruments, the fixed coupling be-
tween the virtual and physical environments constrains the af-
fordances brought by Mixed Reality, such as per-musician free
navigation in or multi-scale control of virtual structures.
We designed gRAinyCloud, as a way to reintegrate these lost
affordances to a co-located instrument. It allows for the expressive
exploration of a set of sounds represented by a virtual structure
of shapes placed in the physical space and shared between musi-
cians. Above all, gRAinyCloud enables each musician to freely
manipulate their own viewpoint, changing its scale, position and
rotation, effectively decoupling the physical and virtual spaces,
and to switch between self, other’s and absolute viewpoint while
playing. We describe the implementation of this decoupling of
spaces and analyse its uses and implications for collective musical
expression, by relying on a first-person approach