Selectable component

Usage:

<a-scene>
  <a-entity selectable>
    <a-cube position="-2 0 0"></a-cube>
    <a-cube position="2 0 0"></a-cube>
  </a-entity>

  <a-camera position="0 1.8 5">
    <a-entity
      cursor="maxDistance: 30; timeout: 500"
      position="0 0 -5"
      geometry="primitive: ring; radiusInner: 0.1; radiusOuter: 0.15; segmentsTheta: 32"
      material="color: #ff7700; shader: flat">
    </a-entity>
  </a-camera>
<a-scene>

Now everything inside the first entity will be selectable. Focus the ring on it, and click, to put a bounding box around the selected entity. Fires a selected event on the element with the selectable attribute.

document.querySelector('a-entity[selectable]').addEventListener('selected', (e) => {
  console.log(e.selected);
});

Only one thing at a time can be selected, but I'm open to pull requests to allow multi-selection.

Click an element again to toggle selection.

Click anywhere else in the scene to remove the selection.