docs: function buildNodeHierachy( nodeId, parentObject, allNodes ) {
  
  			var _node = allNodes[ nodeId ];
  			parentObject.add( _node );
  
  			var node = json.nodes[ nodeId ];
  
  			if ( node.children ) {
  
  				var children = node.children;
  
  				for ( var i = 0, l = children.length; i < l; i ++ ) {
  
  					var child = children[ i ];
  					buildNodeHierachy( child, _node, allNodes );
  
  				}
  
  			}
  
  		}