if touching object move to location aframe

I am wondering how it would be possible in aframe if the camera reaches 20 spaces away from the point 0 0 0 to teleport them back to that point. Would something like this be easy to achieve or difficult? How can I achieve this.

Solution

You can get the position of the object using el.object3D.position - that would return x,y,z vector or you can use el.object3D.position.x (or .y / .z for just one axis).

You can also set the position using the same function el.object3D.position.x = 23.12.

As @Piotr Adam Milewski said, you would need to calculate the distance - you could use the following expression distance = sqrt(x^2 + y^2 + z^2) or use the THREE.Vector3.distanceTo() then compare it to some value and set the position accordingly (camera default position is 0, 1.6, 0 and not 0, 0, 0).

A very simple example:

<!DOCTYPE html>
<html lang="en">

<head>
  <script src="https://aframe.io/releases/1.2.0/aframe.min.js"></script>
  <meta charset="UTF-8" />
</head>

<body>
  <script>
    AFRAME.registerComponent('limit-my-distance', {
      init: function() {
        this.zero = new THREE.Vector3(0, 0, 0);
      },
      tick: function() {
        if (this.el.object3D.position.distanceTo(this.zero) > 10) {
          this.el.object3D.position.set(0, 1.6, 0);
        }
        //this.el.object3D.position.x += 0.1;
      }
    });
  </script>
  <a-scene>
    <a-sphere position="0 2 -10"color="red"></a-sphere>
    <a-plane color="green" position="0 0 -5" rotation="-90 0 0" width="20" height="20"></a-plane>
    <a-camera limit-my-distance></a-camera>
    <a-sky color="#fff"></a-sky>
  </a-scene>
</body>

</html>