SOURCE

/*
Most of the stuff in here is just bootstrapping. Essentially it's just
setting ThreeJS up so that it renders a flat surface upon which to draw 
the shader. The only thing to see here really is the uniforms sent to 
the shader. Apart from that all of the magic happens in the HTML view
under the fragment shader.
*/

let container;
let camera, scene, renderer;
let uniforms;

function init() {
  container = document.getElementById( 'container' );

  camera = new THREE.Camera();
  camera.position.z = 1;

  scene = new THREE.Scene();

  var geometry = new THREE.PlaneBufferGeometry( 2, 2 );

  uniforms = {
    u_time: { type: "f", value: 1.0 },
    u_resolution: { type: "v2", value: new THREE.Vector2() },
    u_mouse: { type: "v2", value: new THREE.Vector2() }
  };

  var material = new THREE.ShaderMaterial( {
    uniforms: uniforms,
    vertexShader: document.getElementById( 'vertexShader' ).textContent,
    fragmentShader: document.getElementById( 'fragmentShader' ).textContent
  } );

  var mesh = new THREE.Mesh( geometry, material );
  scene.add( mesh );

  renderer = new THREE.WebGLRenderer();
  renderer.setPixelRatio( window.devicePixelRatio );

  container.appendChild( renderer.domElement );

  onWindowResize();
  window.addEventListener( 'resize', onWindowResize, false );

  document.onmousemove = function(e){
    uniforms.u_mouse.value.x = e.pageX
    uniforms.u_mouse.value.y = e.pageY
  }
}

function onWindowResize( event ) {
  renderer.setSize( window.innerWidth, window.innerHeight );
  uniforms.u_resolution.value.x = renderer.domElement.width;
  uniforms.u_resolution.value.y = renderer.domElement.height;
}

function animate() {
  requestAnimationFrame( animate );
  render();
}

function render() {
  uniforms.u_time.value += 0.05;
  renderer.render( scene, camera );
}



init();
animate();

<script src="https://cdnjs.cloudflare.com/ajax/libs/three.js/88/three.min.js"></script>
<script id="vertexShader" type="x-shader/x-vertex">
    void main() {
        gl_Position = vec4( position, 1.0 );
    }
</script>
<script id="fragmentShader" type="x-shader/x-fragment">
  
  
    uniform vec2 u_resolution;
    uniform vec2 u_mouse;
    uniform float u_time;
    uniform vec3 u_colours[ 5 ];
  
    const float multiplier = .7;
  
    const float zoomSpeed = 8.;
    const int layers = 6;
  
    const float seed =    86135.7315468;
  
    float random2d(vec2 uv) {
      return fract(
                sin(
                  dot( uv.xy, vec2(12.9898, 78.233) )
                ) * seed);
    }
    mat2 rotate2d(float _angle){
        return mat2(cos(_angle),sin(_angle),
                    -sin(_angle),cos(_angle));
    }

  // Created by inigo quilez - iq/2013
  // License Creative Commons Attribution-NonCommercial-ShareAlike 3.0 Unported License.
  // http://www.iquilezles.org/www/articles/voronoilines/voronoilines.htm

  vec2 random2( vec2 p ) {
      return fract(sin(vec2(dot(p,vec2(127.1,311.7)),dot(p,vec2(269.5,183.3))))*43758.5453);
  }

  vec3 voronoi( in vec2 x, inout vec2 nearest_point, inout vec2 s_nearest_point, inout float s_nearest_distance, inout float nearest_distance) {
      vec2 n = floor(x);
      vec2 f = fract(x);

      // first pass: regular voronoi
      vec2 mg, mr;
      float md = 8.0;
      float smd = 8.0;
      for (int j= -1; j <= 1; j++) {
          for (int i= -1; i <= 1; i++) {
              vec2 g = vec2(float(i),float(j));
              vec2 o = random2( n + g );
              // o = 0.5 + 0.4*sin((u_time / 10.) + 6.2831*o);
              // o *= length(mouse.y) * 2.;

              vec2 r = g + o - f;
              float d = dot(r,r);

              if( d<md ) {
                  smd = md;
                  s_nearest_distance = md;
                  nearest_distance = d;
                  md = d;
                  mr = r;
                  mg = g;
                  nearest_point = r;
              } else if( smd > d ) {
                  s_nearest_distance = d;
                  nearest_distance = d;
                  smd = d;
                  s_nearest_point = r;
              }
          }
      }

      // second pass: distance to borders
      md = 8.0;
      for (int j= -2; j <= 2; j++) {
          for (int i= -2; i <= 2; i++) {
              vec2 g = mg + vec2(float(i),float(j));
              vec2 o = random2( n + g );
              // o = 0.5 + 0.4*sin((u_time / 10.) + 6.2831*o);
              // o *= length(mouse.y) * 2.;

              vec2 r = g + o - f;

              if ( dot(mr-r,mr-r)>0.00001 ) {
                  md = min(md, dot( 0.5*(mr+r), normalize(r-mr) ));
              }
          }
      }
      return vec3(md, mr);
  }
  
  vec3 getColour(vec2 nearest_point, vec2 s_nearest_point, float modMultiplier) {
    
    return vec3(0.);
  }
  
  vec3 render(vec2 uv) {
    vec3 colour = vec3(0.5);
    // Voronoi
    vec2 nearest_point = vec2(0., 0.);
    vec2 s_nearest_point = vec2(0., 0.);
    float s_nearest_distance = 0.;
    float nearest_distance = 0.;
    vec3 c = voronoi(uv, nearest_point, s_nearest_point, s_nearest_distance, nearest_distance);

    // colour
    colour = getColour(nearest_point, s_nearest_point, 10.);
    
    // colour.r = length(fract(length(dot(nearest_point, s_nearest_point) * 5.)));
    // colour = vec3(0.5);
    colour.r = abs(1.-length(nearest_point));
    // colour.g = colour.r / 4.;
    // colour.b = colour.r / 3.;
    // vec3 linecolour = vec3(colour.r, 1. * colour.r, colour.r);
    // colour = mix(colour, linecolour, smoothstep(.60, .70, fract(length(nearest_point) * 5.)) * smoothstep(1., .85, fract(length(nearest_point) * 5.)));

    // borders
    vec3 border = vec3(-4.);
    colour = mix( border, colour, smoothstep( -.1, 0.03, c.x ) );
    // colour += mix( vec3(0.07), vec3(0.), smoothstep( 0.12, 0.11, c.x - 0.08 ) );
    
    return colour;
  }
  
  vec3 renderLayer(int layer, int layers, vec2 uv, inout float opacity) {
    // Scale
    // Generating a scale value between zero and 1 based on a mod of u_time
    // A frequency of 10 dixided by the layer index (10 / layers * layer)
    float scale = mod((u_time + zoomSpeed / float(layers) * float(layer)) / zoomSpeed, -1.);
    uv *= 15.; // The initial scale. Increasing this makes the cells smaller and the "speed" apepar faster
    uv *= scale; // then modifying the overall scale by the generated amount
    uv = rotate2d(u_time / 10.) * uv; // rotarting
    uv += vec2(1000.) * float(layer); // ofsetting the UV by an arbitrary amount to make the layer appear different

    // render
    vec3 pass = render(uv * multiplier); // render the pass
    
     // this is the opacity of the layer fading in from the "bottom"
    opacity = 1. + scale;
    float _opacity = opacity;
    
    // This is the opacity of the layer fading out at the top (we want this minimal, hence the smoothstep)
    float endOpacity = smoothstep(0., 0.2, scale * -1.);
    opacity += endOpacity;
    
    return pass * _opacity * endOpacity;
  }

  void main() {
      vec2 uv = (gl_FragCoord.xy - 0.5 * u_resolution.xy);
      
      if(u_resolution.y < u_resolution.x) {
        uv /= u_resolution.y;
      } else {
        uv /= u_resolution.x;
      }
    
      uv.x += sin(u_time / 10.) * .5;
    
      vec3 colour = vec3(0.);
        
      float opacity = 1.;
      float opacity_sum = 1.;
    
      for(int i = 1; i <= layers; i++) {
        colour += renderLayer(i, layers, uv, opacity);
        opacity_sum += opacity;
      }
    
      colour /= opacity_sum;
    
      gl_FragColor = vec4(colour * 5.,1.0);
  }
</script>


<div id="container"></div>

body {
  margin: 0;
  padding: 0;
}

#container {
  position: fixed;
}