Front Distance — tdlidar_frontdist

Wave your hand toward the front of the phone to ride a fader — the contactless air-fader for live control.

Category: Camera & Vision · Tier: Free · Needs: front TrueDepth (Face ID iPhone)

What it does

Uses the front TrueDepth camera to measure how close the nearest thing is to the screen and gives you one clean number from 0 to 1. Move your hand (or yourself) toward the phone and the value rises; pull away and it falls. The near/far range is adjustable in the app, so you can tune how big a gesture spans the full 0–1 sweep. This is the headline “air-fader”: one hand, no touch, one continuous control.

OSC in

| address | type | range | rate | |—|—|—|—| | /tdlidar/frontdist/norm | float | 0–1 normalized nearest distance (front TrueDepth) | depth rate |

Outputs

out1 (CHOP) — one channel: tdlidar/frontdist/norm (0–1). The node tile previews out1.

Parameters

| par | default | what it does | |—|—|—| | OSC Port | 9000 | UDP port to listen on (match the app) |

Quick start (beginner)

  1. In the app, enable Front Distance and set the near/far range to a comfortable arm’s reach.
  2. Drop the Front Distance op — out1 sits somewhere in 0–1.
  3. Move your hand toward and away from the phone’s screen; the value sweeps.
  4. Wire out1 straight into any 0–1 parameter — a crossfader, opacity, a Blur amount — and you’ve got a hands-free fader.

Advanced patterns

  • Map with Range CHOP: the channel is already 0–1 but rarely fills the whole range cleanly; a Range CHOP (set From Range to the min/max you actually reach, To Range 0–1) gives you full-throw control and lets you invert (1→0) so “closer = less”.
  • Smooth the hand-shake: a Lag CHOP (0.05–0.15) or Filter CHOP removes the micro-jitter of a hovering hand without adding noticeable latency to a deliberate move.
  • Zones instead of a fader: Logic CHOP thresholds carve the sweep into bands (far / mid / near) to switch scenes by hand height, like a stepped selector.
  • Two-handed feel: combine with tdlidar_pinch or a Touch op so distance sets coarse value and a pinch confirms/latches it.

Gotchas

  • This is normalized 0–1, not metres — if you need real distance use the rear Back Distance op instead.
  • The full 0–1 sweep depends on the range set in the app; if the value barely moves, widen (or narrow) that range, or remap with a Range CHOP.
  • TrueDepth has a limited near/far working distance — too close or too far reads as a clamped 0 or 1. Keep gestures inside arm’s reach.
  • It reports the nearest surface, so anything closer than your hand (a sleeve, the desk edge) hijacks the value. Keep the front field clear.