code: function ( deformers, geometryMap, materialMap ) {
  
  			sceneGraph = new THREE.Group();
  
  			var modelMap = this.parseModels( deformers.skeletons, geometryMap, materialMap );
  
  			var modelNodes = fbxTree.Objects.Model;
  
  			var self = this;
  			modelMap.forEach( function ( model ) {
  
  				var modelNode = modelNodes[ model.ID ];
  				self.setLookAtProperties( model, modelNode );
  
  				var parentConnections = connections.get( model.ID ).parents;
  
  				parentConnections.forEach( function ( connection ) {
  
  					var parent = modelMap.get( connection.ID );
  					if ( parent !== undefined ) parent.add( model );
  
  				} );
  
  				if ( model.parent === null ) {
  
  					sceneGraph.add( model );
  
  				}
  
  
  			} );
  
  			this.bindSkeleton( deformers.skeletons, geometryMap, modelMap );
  
  			this.createAmbientLight();
  
  			this.setupMorphMaterials();
  
  			var animations = new AnimationParser().parse();
  
  			// if all the models where already combined in a single group, just return that
  			if ( sceneGraph.children.length === 1 && sceneGraph.children[ 0 ].isGroup ) {
  
  				sceneGraph.children[ 0 ].animations = animations;
  				sceneGraph = sceneGraph.children[ 0 ];
  
  			}
  
  			sceneGraph.animations = animations;
  
  		}
docs: create the main THREE.Group() to be returned by the loader