(refer to Kostas Terzidis's Algorithms for Visual Design, pp.139)

A small tweak of the background alpha value can make the previous frame fading away ...

haven't figured out how to make this effect in 3D scene ... advices are appreciated!

1. import processing.opengl.*;
   //import peasy.*;
   //PeasyCam cam;
   
   PGraphicsOpenGL pg; // define a PGraphics type of buffer object
   int dim =500;
   
   void setup(){
     size(dim, dim, OPENGL);
     background(100);
   //  cam = new PeasyCam(this,600);
     pg = (PGraphicsOpenGL)createGraphics(dim,dim,P3D); // create a buffer object
   }
   
   void draw(){
     image(pg, 0, 0); // draw the buffer
   }
   
   int x1,y1,x2,y2;
   
   void mouseClicked(){
     pg.beginDraw(); // start writing to the buffer
     pg.background(0,10); // previous frame will fade out, the smaller the alpha, the slower the fading
   
     for (int i=0; i<100; i++){
       x1 = int(random(dim)); y1 = int(random(dim));
       x2 = int(random(dim)); y2 = int(random(dim));
       pg.stroke(255);
       pg.strokeWeight(1);
       pg.line(x1,y1,x2,y2);
       pg.stroke(random(255),random(255),random(255));
       pg.strokeWeight(random(1,10));
       pg.point(x1,y1);
       pg.strokeWeight(random(10,20));
       pg.point(x2,y2);
     }
    
     pg.endDraw(); // end writing to the buffer
   }