title: Meshlab / Meshlabserver - How to detect the normal orientation of loaded .ply?
body: <p>I have many .ply files.</p>
  
  <p>With some reasons, some of their normal orientations are pointing outside of the object(which is what I want) and some of them are pointing inside the object.</p>
  
  <p><a href="https://i.stack.imgur.com/cIqwo.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/cIqwo.png" alt="enter image description here"></a></p>
  
  <p>Does Meshlabserver has a function that can detect the normal orientation of a .ply file, and another function that can unify all the normal to a specific orientation?</p>
  
  <p>By the way, since I am new to 3D ojects, I would like to know what factor determines the normal orientation? Hope someone willing to answer my question.</p>
  
  <p>Thanks.</p>