title: How to add lines to 3D?
body: <p><a href="https://i.stack.imgur.com/NH1sB.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/NH1sB.png" alt="3D_Image"></a></p>
  
  <p>I rendered a 3D human model using three.js and I was wondering how to add angle lines like the one I painted on the 3D image in red colored line.</p>