An Internal Other

The body as a site of transformation — interrogated through gesture, answered in particles.

An Internal Other is an interactive installation made for Liquid Bodies, a double exhibition at Medicinsk Museion and Politikens Forhal, Copenhagen, exploring stem cells and biotechnology. The work is part of Hope Springs Eternal, an international research and dissemination project anchored in the PREPARE group at the Novo Nordisk Foundation Center for Stem Cell Medicine (reNEW).

Participants stand before a large vertical screen. The system idles in a standby particle state until a body enters the frame, at which point the installation begins. The interaction unfolds across four sequential phases, each presenting a question answered through hand gesture alone.

We built the installation in TouchDesigner. Hand tracking runs via MediaPipe to compute audiences pose that drives intersection tests and phase transitions. Each phase has its own logic for evaluating gesture state against visual targets, including a threshold region that detects when a raised hand crosses a defined boundary, advancing the sequence.

The particle system runs in two parallel variants: one traces the edge-detected body silhouette, the other fills the full body outline. Both are driven by Lucas-Kanade optical flow computed entirely on the GPU, so that movement in the image plane becomes force in the particle field. Parameter states across all four phases are managed using a preset system with named snapshots, tagging, and override modes controlling how transitions behave when live state conflicts with stored values.

Medicinsk Museion / Politikens Forhal, Copenhagen, 2026.