A-Frame custom component

index.html

<script>
    var direction = 1;
    AFRAME.registerComponent('auto-camera', {
        tick: function () {
          var currentPosition = this.el.object3D.position;
          if (currentPosition.z < -2) {
            direction = 1;
          } else if (currentPosition.z > 0) {
            direction = -1;
          }
          var delta = 0.05;
          
          this.el.setAttribute('position', {
            x: currentPosition.x,
            y: currentPosition.y,
            z: currentPosition.z + delta * direction
          });
        }
    });
</script>

<a-entity position="0 1.6 0" auto-camera>
    <a-camera></a-camera>
</a-entity>