Endless Hallway 403 Forbidden Page

Endless Hallway 403 Forbidden Page developed using CSS, HTML, Three.js and JavaScript. Demo and download avilable.

HTML Snippet

<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 float u_time;
    uniform vec2 u_mouse;
  uniform sampler2D u_plate;
  
    const int octaves = 2;
    const float seed = 43758.5453123;
    const float seed2 = 73156.8473192;
    // Epsilon value
    const float eps = 0.005;
  
    // movement variables
    vec3 movement = vec3(.0);

    // Gloable variables for the raymarching algorithm.
    const int maxIterations = 256;
    const float stepScale = .7;
    const float stopThreshold = 0.001;
  
  const float PI = 3.14159;
  
  
  
  vec3 path(float delta) {
    return vec3(0., 0., -delta*3.);
  }
  
  
  float length2( vec2 p )
  {
    return sqrt( p.x*p.x + p.y*p.y );
  }

  float length6( vec2 p )
  {
    p = p*p*p; p = p*p;
    return pow( p.x + p.y, 1.0/6.0 );
  }

  float length8( vec2 p )
  {
    p = p*p; p = p*p; p = p*p;
    return pow( p.x + p.y, 1.0/8.0 );
  }
  
  // Distance function primitives
  // Reference: http://iquilezles.org/www/articles/distfunctions/distfunctions.htm
  float sdBox( vec3 p, vec3 b )
  {
    vec3 d = abs(p) - b;
    return min(max(d.x,max(d.y,d.z)),0.0) + length(max(d,0.0));
  }
  float udBox( vec3 p, vec3 b )
  {
    return length(max(abs(p)-b,0.0));
  }
  float udRoundBox( vec3 p, vec3 b, float r )
  {
    return length(max(abs(p)-b,0.0))-r;
  }
  float sdSphere( vec3 p, float s )
  {
    return length(p)-s;
  }
  float sdCylinder( vec3 p, vec3 c )
  {
    return length(p.xz-c.xy)-c.z;
  }
  float sdCappedCylinder( vec3 p, vec2 h )
  {
    vec2 d = abs(vec2(length(p.xz),p.y)) - h;
    return min(max(d.x,d.y),0.0) + length(max(d,0.0));
  }
  float sdTorus82( vec3 p, vec2 t )
  {
    vec2 q = vec2(length2(p.xz)-t.x,p.y);
    return length8(q)-t.y;
  }
  float sdPlane( vec3 p)
  {
    return p.y;
  }
  
  // smooth min
  // reference: http://iquilezles.org/www/articles/smin/smin.htm
  float smin(float a, float b, float k) {
      float res = exp(-k*a) + exp(-k*b);
      return -log(res)/k;
  }
  
  vec3 random3( vec3 p ) {
      return fract(sin(vec3(dot(p,vec3(127.1,311.7,319.8)),dot(p,vec3(269.5,183.3, 415.2)),dot(p,vec3(362.9,201.5,134.7))))*43758.5453);
  }
  vec2 random2( vec2 p ) {
      return fract(sin(vec2(dot(p,vec2(127.1,311.7)),dot(p,vec2(269.5,183.3))))*43758.5453);
  }
  
  // The world!
  float world_sdf(in vec3 p) {
    float world = 10.;
    
    vec2 pxy = p.xy;
    float pz = p.z;
    float delta = pz * .3;
    float s = sin(delta);
    float c = cos(delta);
    mat2 rot = mat2(c, -s, s, c);
    
    p.z = mod(p.z, 1.5) - .75;
    p.xy *= rot;
    // p.z = mod(p.z, 2.) - 1.;
    
    float path = path(u_time).z;
    float animation = smoothstep(-2., -1.5, path - pz + p.z); // Adding the p.z here to make the doors appear solid
    
    const float wallWidth = .02;
    const float doorWidth = .23;
    
    world = udBox(p, vec3(5.,10.,wallWidth)); // wall
    world = min(world, udBox(p + vec3(0., .5, 0.), vec3(5., .05, wallWidth + .015))); // baseboard
    // world = min(world, length(max(abs(p.yz)-vec2(.05, wallWidth + .015),0.0)));
    world = max(world, -sdBox(p, vec3(doorWidth,.5,1.))); // doorframe
    world = min(world, p.y + .5); // floor
    // world = min(world, length(p.zy + vec2(.2))-.05);
    
    const float RAD90 = 1.5708;
    const float cospi = cos(PI);
    const float sinpi = sin(PI);
    const float cosrad90 = cos(RAD90);
    const float sinrad90 = sin(RAD90*1.1);
    c = mix(cospi, cosrad90, animation);
    s = mix(sinpi, sinrad90, animation);
    
    // Door
    vec3 doorP = p;
    doorP.xz *= mat2(c, -s, s, c);
    doorP.x += mix(0.001, doorWidth - .005, animation);
    doorP.z += mix(0., doorWidth - .005, animation);
    world = min(world, sdBox(doorP, vec3(doorWidth -.005,.5-.005,wallWidth)));
    
    // Plate
    vec3 plateoffset = vec3(0., -.2, 0.);
    vec2 plateUV = doorP.xy * vec2(-3., 3.) + .5 + plateoffset.xy * 3.;
    float t = 1. - texture2D(u_plate, plateUV).x;
    world = min(world, sdBox(doorP + plateoffset, vec3(doorWidth*.8,.1,wallWidth+.01 * t + .005)));
    
    // Door handle
    doorP.x += .12;
    doorP.z -= .05;
    doorP.y += .05;
    world = min(world, sdSphere(doorP, .03));
    
    
    return world;
  }
  
  // Fuck yeah, normals!
  vec3 calculate_normal(in vec3 p)
  {
    const vec3 small_step = vec3(0.0001, 0.0, 0.0);
    
    float gradient_x = world_sdf(vec3(p.x + eps, p.y, p.z)) - world_sdf(vec3(p.x - eps, p.y, p.z));
    float gradient_y = world_sdf(vec3(p.x, p.y + eps, p.z)) - world_sdf(vec3(p.x, p.y - eps, p.z));
    float gradient_z = world_sdf(vec3(p.x, p.y, p.z  + eps)) - world_sdf(vec3(p.x, p.y, p.z - eps));
    
    vec3 normal = vec3(gradient_x, gradient_y, gradient_z);

    return normalize(normal);
  }

  // Raymarching.
  float rayMarching( vec3 origin, vec3 dir, float start, float end, inout float field ) {
    
    float sceneDist = 1e4;
    float rayDepth = start;
    for ( int i = 0; i < maxIterations; i++ ) {
      sceneDist = world_sdf( origin + dir * rayDepth ); // Distance from the point along the ray to the nearest surface point in the scene.

      if (( sceneDist < stopThreshold ) || (rayDepth >= end)) {        
        break;
      }
      // We haven't hit anything, so increase the depth by a scaled factor of the minimum scene distance.
      rayDepth += sceneDist * stepScale;
    }
  
    if ( sceneDist >= stopThreshold ) rayDepth = end;
    else rayDepth += sceneDist;
      
    // We've used up our maximum iterations. Return the maximum distance.
    return rayDepth;
  }

  // Based on original by IQ - optimized to remove a divide
  float calculateAO(vec3 p, vec3 n)
  {
     const float AO_SAMPLES = 5.0;
     float r = 0.0;
     float w = 1.0;
     for (float i=1.0; i<=AO_SAMPLES; i++)
     {
        float d0 = i * 0.15; // 1.0/AO_SAMPLES
        r += w * (d0 - world_sdf(p + n * d0));
        w *= 0.5;
     }
     return 1.0-clamp(r,0.0,1.0);
  }
  
  

var container = void 0;
var camera = void 0,scene = void 0,renderer = void 0;
var uniforms = void 0;

var loader = new THREE.TextureLoader();
var texture = void 0,plate = void 0;
loader.setCrossOrigin("anonymous");
loader.load(
'https://s3-us-west-2.amazonaws.com/s.cdpn.io/982762/noise.png',
function (tex) {
  texture = tex;
  texture.wrapS = THREE.RepeatWrapping;
  texture.wrapT = THREE.RepeatWrapping;
  texture.minFilter = THREE.LinearFilter;
  loader.load('https://s3-us-west-2.amazonaws.com/s.cdpn.io/982762/403-2.png', function (tex) {
    plate = tex;
    init();
    animate();
  });
});


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_noise: { type: "t", value: texture },
    u_plate: { type: "t", value: plate },
    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 });

  material.extensions.derivatives = true;

  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.addEventListener('pointermove', function (e) {
    var ratio = window.innerHeight / window.innerWidth;
    uniforms.u_mouse.value.x = (e.pageX - window.innerWidth / 2) / window.innerWidth / ratio;
    uniforms.u_mouse.value.y = (e.pageY - window.innerHeight / 2) / window.innerHeight * -1;

    e.preventDefault();
  });
}

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 += 0.01;
  renderer.render(scene, camera);
}

Preview

https://codepen.io/shubniggurath/pen/RYEQqp