Consider visibility from camera viewpoint using e.g https://stackoverflow.com/questions/17624021/determine-if-a-mesh-is-visible-on-the-viewport-according-to-current-camera
see
```javascript
document.querySelector("[line]").object3D.children[0].material =
new THREE.LineBasicMaterial( { vertexColors: true, depthTest: false, depthWrite: false, toneMapped: false, transparent: true } )
```
to force a line as overlay, remaining visible over other objects.
From https://github.com/mrdoob/three.js/blob/master/src/helpers/SkeletonHelper.js#L46
e.g HUD pointer or camera
Also useful for #36
Consider visibility from camera viewpoint using e.g https://stackoverflow.com/questions/17624021/determine-if-a-mesh-is-visible-on-the-viewport-according-to-current-camera
see
to force a line as overlay, remaining visible over other objects.
From https://github.com/mrdoob/three.js/blob/master/src/helpers/SkeletonHelper.js#L46