How to get the global/world position of a child object?

Question

How do I get the global position of an Object3D inside another Object3D?

setup:

var parent = new THREE.Object3D(); parent.position.set(100, 100, 100);  var child = new THREE.Object3D(); child.position.set(100, 100, 100); parent.add(child);  scene.add(parent); 

notes:

I thought that this would be the way to do it:

console.log(child.localToWorld(parent.position)); 

...but it gives me (100, 100, 100), not (200, 200, 200).

Answer 1

You can extract the world position like so:

var target = new THREE.Vector3(); // create once an reuse it  child.getWorldPosition( target ); 

target will contain the result.

EDIT: updated to three.js r.120

Answer 2

In threejs r89 you can just get the world position by Object3D.getWorldPosition. I don't know when it was added.