Television Static

noahbuddy

While trying to build a completely different effect, I noticed a few blips on the screen that looked like an old TV. Thought I would share. Click to "change channels"

Edit: Thanks Quark. I flipped the comparison at the top of the for-loop. HTML and greater than/less than symbols do not always get along.

PVector v;
PVector p;
PVector rx;
PVector rz;

int C = 64;
int LIM = C - 1;
int posrange = 64;
int subrange = 32;

float angx = 0; // degrees
float angz = 0; // degrees

int BUNCHATIMES = 16000; //how much static

void setup() {
  size(512,512,P3D);
  
  angx = 321;
  angz = 280;
  v = new PVector(-17, -19, 26);
  
  //Using vectors of unit length will let us rotate without changing speed
  rz = new PVector(cos(angx*PI/180), sin(angx*PI/180), 0);
  rx = new PVector(0, sin(angz*PI/180), cos(angz*PI/180));
  p = new PVector(0, 0, 0);
  
  frameRate(30);
}

void mouseClicked() {
  v.set(random(posrange)-subrange, random(posrange)-subrange, random(posrange)-subrange);
  p.set(0, 0, 0); //start point could be random too
  
  if (random(1) > 0.5) { //not necessary but seems to change the behavior
    v.normalize();
  }
  
  angx = random(360); // degrees
  angz = random(360); // degrees
  
  rz.set(cos(angx*PI/180), sin(angx*PI/180), 0);
  rx.set(0, sin(angz*PI/180), cos(angz*PI/180));
  
  //if you want to save a pattern for later
  println("V: " + v);
  println("angx: " + angx);
  println("angz: " + angz);
}

void rotz(PVector vec, PVector ro) {
  float x = vec.x*ro.x - vec.y*ro.y;
  float y = vec.x*ro.y + vec.y*ro.x;
  vec.x = x;
  vec.y = y;
}

void rotx(PVector vec, PVector ro) {
  float z = vec.z*ro.z - vec.y*ro.y;
  float y = vec.z*ro.y + vec.y*ro.z;
  vec.z = z;
  vec.y = y;
}

void draw() {
  background(20);
  loadPixels();
  
  for (int i=0; BUNCHATIMES>i; i++) {

    rotz(v, rz);
    rotx(v, rx);
    
    p.add(v);
    
    if (p.x > LIM) p.x = p.x - LIM+1;
    if (p.y > LIM) p.y = p.y - LIM+1;
    if (p.z > LIM) p.z = p.z - LIM+1;
    
    if (p.x < 0) p.x = p.x + LIM;
    if (p.y < 0) p.y = p.y + LIM;
    if (p.z < 0) p.z = p.z + LIM;
    
    translate(width/2, height/2);
    
    //map x,y,z to somewhere in x,y only
    int counter = (int(p.z) << 12) | (int(p.y) << 6) | int(p.x);
    if ( (counter < pixels.length) && (counter >= 0)) {
      pixels[counter] = color(255);
    }
  }
  
  updatePixels();

}

I've found a few interesting patterns, replace lines in setup():

angx = 0; angz = 1; v = new PVector(-0.6633987, 0.6191721, -0.4201525);

angx = 14; angz = 4; v = new PVector(-31, 7, -3);

v = new PVector( -31.0, 11.0, 10.0 ); angx = 310.0; angz = 60.0;

v = new PVector( -17.0, -19.0, 26.0 ); angx = 321.0; angz = 280.0;

v = new PVector( 19.0, -28.0, -19.0 ); angx = 0.0; angz = 299.0;

v = new PVector( 26.0, 18.0, 29.0 ); angx = 194.0; angz = 257.0;

v = new PVector( -15.703075, 0.044879913, -27.758442 ); angx = 10.141991; angz = 292.61026;

quark

There are errors on line 69