GuruBlog

For this animation I used an image sequence to switch between a transparent and an opaque material in cycles.

To generate the image texture I wrote a processing sketch that animates black stripes growing from bottom to top at various speeds. (see below for the sourcecode of the processing sketch)

you can download the blend file here

this is the processing sketch I used to generated the image sequence for the animated texture

float[] speed = new float[20];
float[] h = new float[20];
float w;
float f;
void setup() {
  size(600,300);
  fill(0);
  for ( int i=0; i<speed.length; i++) {
    speed[i]= random( 0.5, 1);
    h[i]=0;
  }
  w = width/speed.length;
  f = float(height)/250.0/0.5;
}



void draw() {
  background(255);
  fill(0);
  for ( int i=0; i<speed.length; i++) {
    if (h[i] < height) h[i]+= speed[i]*f;
    rect( i*w, height-h[i], w, h[i] );
  }
  if ( frameCount <= 250 ) {
    saveFrame( "grow-####.png");
  }
}

and here is an example what the generated texture looks like