It happens on a project I'm working on, not sure still why. I guess this approach is safer.

Base code by now...

Misteriously when using the latest version of the lib on the project I'm working on I'm getting this error:
> Uncaught TypeError: Object [object Object] has no method 'set'
This is caused when THREE.UniformsLib.common.diffuse initialises a THREE.Color (THREE.Color.set() seems to be undefined then).
For some reason this only happens when I load Box2D before three.js. If I load it after is all good. But this fixes the problem too.
/ping @bhouston

Renamed ShaderLib's 'normal2' shader to 'normalmap' as suggested in 4276c9f5.

ShaderUtils relied on ShaderChunks so this created troubles when trying to use three-canvas and three-extras. Besides, better to keep a single library of shaders.

Added support for object groups in the SceneLoader. "groups" is a new property in the SceneLoader result object.

Ex:
input {
  //...
  "objects" : {
    "Object.1" : {
      "groups"    : [ "Group.A" ],
      //...
    },
    "Object.2" : {
      "groups"    : [ "Group.A", "Group.B" ],
      //...
    },
    "Object.3" : {
      "groups"    : [ "Group.B" ],
      //...
    }
  }
}

result {
  //...
  groups: {
    'Group.A': [ 'Object.1', 'Object.2' ],
    'Group.B': [ 'Object.2', 'Object.3' ]
  },
  //...
}

It seems the mystery that was puzzling us for years were quaternion indices (Blender's wxyz vs ours xyzw which wasn't noticeable when using numerical indices).

Local rotations now already ok, still need to deal with global scene rotation.

See #2803

We now have also AddOperation, which was just ignored.

Using classic "loader.load( url, callback )" API instead in OBJLoader, STLLoader, VTKLoader.

OBJMTLLoader is still having just the incorrect EventDispatcher API, but there the situation is more complicated.

SceneLoader: setting visibility of implicitly created children to explicitly specified visibility in JSON.

This is for toggling visibility in hierarchy models loaded from OBJ, UTF8, etc. where in JSON there is just a root node.

Also hierarchy roots now get proper names (instead of those erroneous empties).

Also while doing this I managed to catch another bug (in OrthographicCamera), short variable names are indeed dangerous.

See #2700

See #2700