From sensor to image: design a readable response

Measurement, interpretation, and display have different owners

1. Sensor / data
2. Interpretation / zone
3. Visual state
4. Render / surface

In a proposed scenario, a zone changes a wall’s color when presence is detected. The sensor does not need to generate a skeleton or identify people. A presence input may be enough. If the picture must follow a hand, the required data and coverage test change.

• Data: name, type, units, origin, and receipt time. Specify whether position uses meters, pixels, or normalized values; a tracking ID does not guarantee persistent identity.
• Interpretation: zone boundaries, filtering, and entry/exit conditions. Distinguish “no person” from “no data.”
• Visual state: idle, invitation, active, exit, and assisted mode. Define priority for multiple people and repeated gestures.
• Output: canvas, resolution, frame rate, physical destination, and owner. A valid input does not confirm the projected picture.

Example interface to agree on between integrators: zone_A.present is Boolean; validity is reported separately; the receiver keeps the last receipt time. An agreed expiration period returns the experience to idle and alerts the operator. Adjust that period in prototyping and rehearsal; it is not a universal constant.

TouchDesigner can represent numbers in CHOP channels. When choosing a tool, confirm the interfaces and licenses needed for the project. Coordinate protocols and cues with show control. Before connecting hardware, simulate entry, presence, exit, stalled data, and recovery. This scope covers noncritical image/audio interaction; do not apply these decisions to machinery or safety systems.