title: how to get an objects position in another object's coordinate system THREE.js
body: <p>I have created a THREE.Scene, and within the scene there is an THREE.Object3D() that is a new 'coordinate system'. 
  Inside this object there is a particle with a certain position.
  I understand that getting a this particle's position from the object's 'coordinate System' into the Scene's 'coordinate systems' requires the following</p>
  
  <pre><code>//Gives particle position in scene coordinates
  particle.position.applyMatrix4(Object.matrixWorld) 
  </code></pre>
  
  <p>What would be the inverse transformation though?</p>
  
  <p>(aka, the particle is in the Scene's 'coordinate system' and I want to find its position in the objects 'coordinate system')</p>