HALQA: the collective as interface

The halqa: an interface before computing

In Moroccan public squares, a circle forms around the storyteller: the halqa. That circle is not a backdrop. It is a system of collective sensing — density, orientation, silence, group movement — that captures and responds to an entire crowd. An interaction protocol that has worked for centuries, without a single line of code.

This intuition is the starting point of HALQA, a workshop for designing and prototyping immersive experiences in which collective movement becomes the control.

From body-as-interface to group-as-interface

Most digital art and interaction design training teaches that the body becomes an interface: a gesture, a hand, a silhouette. HALQA shifts the focus: here we work with the group as interface. Not a sum of individuals sensed separately, but a collective dynamic — a flow, a synchrony, a negotiation.

Three regimes of collective interaction

1. Aggregate — the group is sensed as a mass: density, flow, heat. No one is identified, everyone acts. Technically: blob tracking, optical flow, density maps.

2. Coordination — the system rewards synchrony: the image only opens if several bodies move together. Technically: multi-subject pose estimation, phase analysis.

3. Negotiation — participants hold asymmetric roles and must talk to each other to progress. This is where the piece stops being a tech demo and becomes an artwork. Technically: zones, thresholds, shared states.

The tools: from computer vision to sound

The chain runs from sensor to meaning: computer vision and motion tracking (MediaPipe, OpenCV), real-time shaping (TouchDesigner, p5.js / Processing), and routing to image and sound through OSC (Ableton, Max). The core pitfall is not the technique — it is latency and the dead zone where the audience doesn't realize it is acting. The rule: make the interaction legible in under three seconds. A webcam-only path is always available — no one leaves without a working prototype.

The takeaway: the spec sheet beats the code

By the end of the workshop, each participant leaves with two things: a working prototype (running on their own machine, a simple webcam is enough) and a one-page interaction protocol sheet — the chosen regime, thresholds, feedback, and the graceful-degradation mode if tracking fails. The sheet is worth more than the code: it is what makes an idea reproducible and transmissible.

Who it's for, and in what formats

HALQA is designed for art schools, cultural centres, festivals and labs. Non-coders (scenography, dance, performance) are welcome: they take the designer's role, and the prototypes are better for it. Formats: 3 days (21h), 5 days, or a 3-hour masterclass. In French, English or Arabic.

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