code: function processScene(scene) {
        if (!outputJSON.scenes) {
          outputJSON.scenes = [];
          outputJSON.scene = 0;
        }
  
        var gltfScene = {
          nodes: []
        };
  
        if (scene.name !== '') {
          gltfScene.name = scene.name;
        }
  
        outputJSON.scenes.push(gltfScene);
  
        var nodes = [];
  
        for (var i = 0, l = scene.children.length; i < l; i++) {
          var child = scene.children[i];
  
          if (child.visible || options.onlyVisible === false) {
            var node = processNode(child);
  
            if (node !== null) {
              nodes.push(node);
            }
          }
        }
  
        if (nodes.length > 0) {
          gltfScene.nodes = nodes;
        }
      }
docs: Process Scene
  @param  {THREE.Scene} node Scene to process