Processing frame blending code for light painting

//Really simple blending of webcam frames for light painting/POV leds etc.
//For processing 3.0 +, may require edits for older versions.
//Should show 'trails' from light sources for several frames
//And pictures from light painting gear or POV leds
//By devicer.net
//do whatever you like with this code, it's only a basic start :)

import processing.video.*;

Capture video;
int fadeValue = 5; //lower = longer tail, 0 to disable...

void setup() {
  size(640, 480);
  // Uses the default video input, see the reference if this causes an error
  video = new Capture(this, width, height);
  video.start();
  noStroke();
  smooth();
  blendMode(LIGHTEST);
  background(0);
}

void draw() {
  if (video.available()) {
    video.read();
      blendMode(LIGHTEST);//can also use ADD for additive and possibly SCREEN too, see blendMode() reference.
    image(video, 0, 0, width, height); // Draw webcam frame (with lightest blending)
    blendMode(BLEND);  //crude but it works...!
    fill(0,fadeValue);
    rect(0, 0, width, height);
  }
}