.wall{
    background: url(https://s3-us-west-2.amazonaws.com/s.cdpn.io/18515/PIA09959-1280x800_copy.jpg);
    background-size: cover;
  }
  
  html, body{
    height: 100%;
    width: 100%;
    overflow: hidden;
  }
  
  body{
    background: #000;
    text-align: center;
  }
  
  body:before{
    content: '';
    display: inline-block;
    height: 100%;
    vertical-align: middle;
  }
  
  .scene{
    display: inline-block;
    vertical-align: middle;
    perspective: 5px;
    perspective-origin: 50% 50%;
    position: relative;
  }
  
  .wrap{
    position: absolute;
    width: 1000px;
    height: 1000px;
    left: -500px;
    top: -500px;
    transform-style: preserve-3d;
    animation: move 12s infinite linear;
    animation-fill-mode: forwards;
  }
  
  .wrap:nth-child(2){
    animation: move 12s infinite linear;
    animation-delay: 6s;
  }
  
  .wall {
    width: 100%;
    height: 100%;
    position: absolute;
    opacity: 0;
    animation: fade 12s infinite linear;
    animation-delay: 0;
  }
  
  .wrap:nth-child(2) .wall {
    animation-delay: 6s;
  }
  
  .wall-right {
    transform: rotateY(90deg) translateZ(500px);
  }
  
  .wall-left {
    transform: rotateY(-90deg) translateZ(500px);
  }
  
  .wall-top {
    transform: rotateX(90deg) translateZ(500px);
  }
  
  .wall-bottom {
    transform: rotateX(-90deg) translateZ(500px);
  }
  
  .wall-back {
    transform: rotateX(180deg) translateZ(500px);
  }
  
  @keyframes move {
    0%{
      transform: translateZ(-500px) rotate(0deg);
    }
    100%{
      transform: translateZ(500px) rotate(0deg);
    }
  }
  
  @keyframes fade {
    0%{
      opacity: 0;
    }
    25% {
      opacity: 1;
    }
    75% {
      opacity: 1;
    }
    100%{
      opacity: 0;
    }
  }