VPT's Video Trigger detects motion in camera zones by background subtraction to fire events

VPT ships with a companion Video Trigger app (based on Zach Poff’s patch) that uses background detection to sense motion in up to 6 drawn zones and send triggers to VPT over OSC on port 6666. Setup: point a camera at the empty space and memorise the background, then select a zone and drag out a rectangle over the video feed, toggling zones on/off. Its lower section is a router almost identical to VPT’s, but controller numbers here are the zone numbers (1–6) and a per-row mode sets how a trigger is read: the default toggle sends 1 on entry and 0 on exit, while ‘in’ fires only on entry — which avoids a double-trigger for one-shot actions like ‘play a random clip’. One camera cannot serve both the Video Trigger and VPT at once.

Examples

Zone 1 covers a doorway; set it to ‘in’ mode and map it to /sources/1video/random so walking through plays a random clip once, without a second trigger on exit.

Assessment

Explain the difference between ‘toggle’ and ‘in’ trigger modes in the Video Trigger, and give a case where ‘in’ is required. On what port does it talk to VPT?