threejs v87: traverse meshes and map function

traverseMeshes.js

import _ from 'lodash';

function exec(obj, cb) {
  switch (obj.type) {
    case 'Mesh':
    case 'SkinnedMesh':
    case 'LineSegments':
      cb(obj);
      break;
    default:
      break;
  }
}

export default function traverseMeshes(object, callback) {
  // doesn't has children
  if (!object.children || object.children.length < 1) {
    exec(object, callback);
    return;
  }

  _.forEach(object.children, (obj) => {
    exec(obj, callback);
    if (obj.children.length > 0) {
      traverseMeshes(obj, callback);
    }
  });
}