title: three js recalculate vector 3 to child object
body: <p>I have <code>Vector3</code> in position.</p>
  
  <p>I have <code>scene</code> childs:</p>
  
  <pre><code>planet = new THREE.Object3D();
  city= new THREE.Object3D();
  street= new THREE.Object3D();
  
  scene.add(planet);
  planet.add(city);
  city.add(street);
  </code></pre>
  
  <p>how can i get correct world position of vector in each object(<code>planet</code>,<code>city</code> and <code>street</code> <strong>individually</strong>), with respect to <strong>position,scale and rotation</strong> of each object..</p>
  
  <p>i try  <code>planet.worldToLocal(new THREE.Vector3( vector.x,vector.y,vector.z )</code> but it seem to work only from global to child object, not for recalculating from <code>planet</code> to <code>city</code>.</p>
  
  <p>example:</p>
  
  <pre><code>planet.position.set(10,0,0);
  city.position.set(10,0,0);
  street.position.set(10,0,0);
  </code></pre>
  
  <p>if <code>myVector</code> is new <code>THREE.Vector3(0,10,0)</code>, i need to get the same position in street object, that should be <code>(30,10,0)</code> how to get it by THREE functions??</p>