loopFunction.js

function loopFunction() {
  var distance = Math.round(camera.position.x / sectionWidth)
  if (distance !== this.loopSectionPosition) {
    loopSectionPosition = distance
    setInstancedMeshPositions(mesh, loopSectionPosition)
  }
}

function render() {
  // move the camera
  camera.position.x += 5.
  loopFunction()
  renderer.render( scene, camera )
}