script to return or restore rotation of multiple selected objects

function unrotate(item) {
    var grp = false, trs = false;
    var accumRotation = undefined,
        rotationTag;

    if (item.hasOwnProperty('tags')) {
      if (item.typename == "GroupItem" || item.typename == "CompoundPathItem") {
        if (item.typename == "CompoundPathItem") {
          rotationTag = getThing(item.pathItems[0].tags, 'name', 'BBAccumRotation');
          trs = true;
        }
          else {
           rotationTag = getThing(item.pageItems[0].tags, 'name', 'BBAccumRotation');
          grp = true;
          }
      }
      else rotationTag = getThing(item.tags, 'name', 'BBAccumRotation');

    if (rotationTag)
      accumRotation = rotationTag.value * 180 / Math.PI;
    }

    if (
        undefined == accumRotation
        && item.hasOwnProperty('matrix')
    )
        // derive rotation from the matrix
        accumRotation = getRotationFromMatrix(item.matrix);

    if (undefined == accumRotation)
        return;

    // rotate the item
    item.rotate(- accumRotation);

    if (rotationTag)
        // update tag
          var pi;
          if (grp)
            for (var i = 0; i < item.pageItems.length; i++ ){
              pi = item.pageItems[i];
              rotationTag = getThing(pi.tags, 'name', 'BBAccumRotation');
              if (rotationTag != undefined) {rotationTag.value = 0;}
              }
            }
         if (trs) {
            pi = item.pathItems[0];
              rotationTag = getThing(pi.tags, 'name', 'BBAccumRotation');
              if (rotationTag != undefined) {rotationTag.value = 0;}
                rotationTag = getThing(item.tags, 'name', 'BBAccumRotation');
                if (rotationTag != undefined) {rotationTag.value = 0;}
         }
        if (!trs && !grp) rotationTag.value = 0;
};

Okay @vectora98504848 here is the script again, now with René's improved function. Let us know how it goes!

- Mark

/**
 * @file Unrotate Selected Items 2.js
 *
 * Makes an attempt to remove any recorded rotation
 * that can be derived from the selected items.
 * Finds rotation either in the item's BBAccumRotation
 * tag or the item's matrix.
 *
 * @author m1b
 * @version 2025-02-17
 * @discussion https://community.adobe.com/t5/illustrator-discussions/script-to-return-or-restore-rotation-of-multiple-selected-objects/m-p/15146692
 */
(function () {

    var doc = app.activeDocument;

    var items = getItems({
        from: doc.selection,
        getPageItems: true,
        getGroupItems: true,
    });

    if (0 === items.length)
        return alert('Please select some items to rotate and try again.');

    for (var i = 0; i < items.length; i++)
        unrotate2(items[i]);

})();

/**
 * Attempt to return a page item to unrotated state.
 * Modified by renél80416020 to apply rotation
 * to group items and compound path items correctly.
 * Important: will only work if the item has a valid
 * BBAccumRotation tag or a matrix that is ammenable
 * to derivation of the rotation.
 * @author m1b and renél80416020
 * @version 2025-02-14
 * @param {PageItem} item - the item to unrotate.
 * @return {Number} - the amount of rotation, in degrees.
 */
function unrotate2(item) {

    var grp = false, trs = false;

    var accumRotation = undefined,
        rotationTag;

    if (item.hasOwnProperty('tags')) {

        if (item.typename == "GroupItem" || item.typename == "CompoundPathItem") {
            if (item.typename == "CompoundPathItem") {
                rotationTag = getThing(item.pathItems[0].tags, 'name', 'BBAccumRotation');
                trs = true;
            }

            else {
                rotationTag = getThing(item.pageItems[0].tags, 'name', 'BBAccumRotation');
                grp = true;
            }
        }
        else rotationTag = getThing(item.tags, 'name', 'BBAccumRotation');

        if (rotationTag)
            accumRotation = rotationTag.value * 180 / Math.PI;
    }

    if (
        undefined == accumRotation
        && item.hasOwnProperty('matrix')
    )
        // derive rotation from the matrix
        accumRotation = getRotationFromMatrix(item.matrix);

    if (undefined == accumRotation)
        return;

    // rotate the item
    item.rotate(- accumRotation);

    if (rotationTag) {
        // update tag
        var pi;

        if (grp)
            for (var i = 0; i < item.pageItems.length; i++) {
                pi = item.pageItems[i];
                rotationTag = getThing(pi.tags, 'name', 'BBAccumRotation');
                if (rotationTag != undefined) { rotationTag.value = 0; }
            }

        if (trs) {
            pi = item.pathItems[0];
            rotationTag = getThing(pi.tags, 'name', 'BBAccumRotation');
            if (rotationTag != undefined) { rotationTag.value = 0; }
            rotationTag = getThing(item.tags, 'name', 'BBAccumRotation');
            if (rotationTag != undefined) { rotationTag.value = 0; }
        }

        if (!trs && !grp)
            rotationTag.value = 0;

    }

};

/**
 * Returns a thing with matching property.
 * If `key` is undefined, evaluate the object itself.
 * @author m1b
 * @version 2024-04-21
 * @param {Array|Collection} things - the things to look through.
 * @param {String} [key] - the property name (default: undefined).
 * @param {*} value - the value to match.
 */
function getThing(things, key, value) {

    for (var i = 0, obj; i < things.length; i++)
        if ((undefined == key ? things[i] : things[i][key]) == value)
            return things[i];

};

/**
 * Returns the rotation amount, in degrees,
 * of the given (not skewed) matrix.
 * @author m1b
 * @version 2023-10-20
 * @param {Matrix} matrix - an Illustrator Matrix.
 * @returns {Number}
 */
function getRotationFromMatrix(matrix) {

    if (!matrix.hasOwnProperty('mValueA'))
        throw new Error('getRotationFromMatrix: bad `matrix` supplied.');

    // scaling factors
    var scaleX = Math.sqrt(matrix.mValueA * matrix.mValueA + matrix.mValueC * matrix.mValueC);
    // scaleY = Math.sqrt(matrix.mValueB * matrix.mValueB + matrix.mValueD * matrix.mValueD);

    // rotation angle
    var radians = Math.acos(matrix.mValueA / scaleX),
        degrees = radians * (180 / Math.PI);

    return Math.round(degrees * 1000) / 1000;

};

/** ------------------------------------------------------------------- *
 *  GET ITEMS                                                           *
 * -------------------------------------------------------------------- *
 * @author m1b                                                          *
 * @version 2024-03-01                                                  *
 * -------------------------------------------------------------------- *
 * Collects page items from a `from` source, eg. a Document, Layer,     *
 * GroupItem, or Array. Will look inside group items up to `maxDepth`.  *
 * Search can be filtered using `filter` function. Note that the        *
 * filter function is evaluated last in the filtering process.          *
 * -------------------------------------------------------------------- *
 * Example 1. Get all items in document:                                *
 *                                                                      *
 *    var myItems = getItems({ from: app.activeDocument });             *
 *                                                                      *
 * -------------------------------------------------------------------- *
 * Example 2. Get all selected items except groups:                     *
 *                                                                      *
 *    var myItems = getItems({                                          *
 *      from: app.activeDocument.selection,                             *
 *      getGroupItems: false,                                           *
 *    });                                                               *
 *                                                                      *
 * -------------------------------------------------------------------- *
 * Example 3. Using `filter` function to choose item type:              *
 *                                                                      *
 *    var myItems = getItems({                                          *
 *      from: app.activeDocument,                                       *
 *      filter: function (item) {                                       *
 *        return (                                                      *
 *          'PathItem' === item.typename                                *
 *          || 'CompoundPathItem' === item.typename                     *
 *        );                                                            *
 *      }                                                               *
 *    });                                                               *
 *                                                                      *
 * -------------------------------------------------------------------- *
 * Example 4. Using `filter` function:                                  *
 *                                                                      *
 *    var myItems = getItems({                                          *
 *      from: app.activeDocument,                                       *
 *      filter: onlyPngLinks                                            *
 *    });                                                               *
 *                                                                      *
 *    function onlyPngLinks(item, depth) {                              *
 *       return (                                                       *
 *           'PlacedItem' === item.typename                             *
 *           && '.png' === item.file.name.slice(-4).toLowerCase()       *
 *       );                                                             *
 *    };                                                                *
 *                                                                      *
 * -------------------------------------------------------------------- *
 * Example 4. Using the `filter` function for custom collecting:        *
 *                                                                      *
 * This example bypasses the normal returned array and instead          *
 * captures items in an "external" array `itemsByDepth`.                *
 *                                                                      *
 *    var itemsByDepth = [];                                            *
 *                                                                      *
 *    function getItemsByDepth(item, depth) {                           *
 *      if (undefined == itemsByDepth[depth])                           *
 *        itemsByDepth[depth] = [];                                     *
 *      itemsByDepth[depth].push(item);                                 *
 *    };                                                                *
 *                                                                      *
 *    getItems({                                                        *
 *      from: app.activeDocument,                                       *
 *      filter: getItemsByDepth                                         *
 *    });                                                               *
 *                                                                      *
 * -------------------------------------------------------------------- *
 * @param {Object} options - parameters
 * @param {PageItem|Array<PageItem>|Document|Layer} options.from - the thing(s) to look in, eg. a selection.
 * @param {Function} [options.filter] - function that, given a found item, must return true (default: no filtering).
 * @param {Boolean} [options.getPageItems] - whether to include page items in returned items (default: true).
 * @param {Boolean} [options.getGroupItems] - whether to include GroupItems in returned items (default: true).
 * @param {Boolean} [options.getLayers] - whether to include Layers in returned items (default: false).
 * @param {Boolean} [options.getHiddenItems] - whether to include hidden items in returned items (default: true).
 * @param {Boolean} [options.getLockedItems] - whether to include locked items in returned items (default: true).
 * @param {Boolean} [options.getGuideItems] - whether to include guide items in returned items (default: false).
 * @param {Number} [options.maxDepth] - deepest folder level (recursion depth limit) (default: 99).
 * @param {Boolean} [options.returnFirstMatch] - whether to return only the first found item (default: false).
 * @param {Number} [depth] - the current depth (private).
 * @returns {Array|PageItem} - all the found items in a flat array, or the first found item if `returnFirstMatch`.
 */
function getItems(options, depth) {

    // defaults
    options = options || {};

    var found = [],
        depth = depth || 0,
        items = options.from;

    if (!options.initialized)
        // once-off initialization
        if (!initialize())
            return [];

    itemsLoop:
    for (var i = 0, item, len = items.length; i < len; i++) {

        item = items[i];

        if (
            false === excludeFilter(item)
            && true === includeFilter(item)
        ) {
            // item found!
            found.push(item);

            if (options.returnFirstMatch)
                break itemsLoop;
        }

        if (
            'GroupItem' !== item.constructor.name
            && 'Layer' !== item.typename
        )
            // only items with children from here
            continue itemsLoop;

        if (
            excludeHidden(item)
            || excludeLocked(item)
        )
            // don't look into excluded containers
            continue itemsLoop;

        if (depth >= options.maxDepth)
            // don't go deeper
            continue itemsLoop;

        // set up for the next depth
        options.from = item.pageItems;

        // look inside
        found = found.concat(getItems(options, depth + 1));

    }

    // this level done
    if (true == options.returnFirstMatch)
        return found[0];
    else
        return found;

    /**
     * Returns true when the item should be not be found.
     * @param {PageItem|Layer} item
     * @returns {Boolean}
     */
    function excludeFilter(item) {

        return (

            isAlreadyFound(item)

            // is hidden
            || excludeHidden(item)

            // is locked
            || excludeLocked(item)

            // is guide
            || (
                false === options.getGuideItems
                && true === item.guides
            )

            // is layer
            || (
                false === options.getLayers
                && 'Layer' === item.typename
            )

            // is group item
            || (
                false === options.getGroupItems
                && 'GroupItem' === item.typename
            )

            // is page item
            || (
                false === options.getPageItems
                && 'GroupItem' !== item.typename
                && undefined != item.uuid
            )

        );

    };

    /**
     * Returns true when the item should be included.
     * @param {PageItem|Layer} item
     * @returns {Boolean}
     */
    function includeFilter(item) {

        return (
            undefined == options.filter
            || options.filter(item, depth)
        );

    };

    /**
     * Returns true when the item should
     * be excluded because it is hidden.
     * @param {PageItem|Layer} item
     * @returns {Boolean}
     */
    function excludeHidden(item) {

        return (
            false === options.getHiddenItems
            && (
                true === item.hidden
                || false === item.visible
            )
        );

    };

    /**
     * Returns true when the item should
     * be excluded because it is locked.
     * @param {PageItem|Layer} item
     * @returns {Boolean}
     */
    function excludeLocked(item) {

        return (
            false === options.getLockedItems
            && true === item.locked
        );

    };

    /**
     * Returns true if item was already
     * found, and marks item as found,
     * to avoid finding same item twice.
     * @param {PageItem|Layer} item
     * @returns {Boolean}
     */
    function isAlreadyFound(item) {

        var uuid = item.hasOwnProperty('uuid')
            ? item.uuid
            : item.typename + item.zOrderPosition,

            isFound = !!options.isFound[uuid];

        options.isFound[uuid] = true;

        return isFound;

    }

    /**
     * Returns the initialised `options` object.
     * @returns {Object}
     */
    function initialize() {

        // make a new object, so we don't pollute the original
        options = {
            initialized: true,
            depth: 0,
            isFound: {},
            filter: options.filter,
            getPageItems: false !== options.getPageItems,
            getGroupItems: false !== options.getGroupItems,
            getLayers: true === options.getLayers,
            getHiddenItems: false !== options.getHiddenItems,
            getLockedItems: false !== options.getLockedItems,
            getGuideItems: true === options.getGuideItems,
            maxDepth: options.maxDepth,
            returnFirstMatch: options.returnFirstMatch,
        };

        if (
            undefined == options.maxDepth
            || !options.maxDepth instanceof Number
        )
            options.maxDepth = 99;

        // items is a single layer
        if ('Layer' === items.typename)
            items = [items];

        // items is a document
        else if ('Document' === items.constructor.name) {

            var layers = items.layers;
            items = [];

            for (var i = 0; i < layers.length; i++)
                items.push(layers[i]);

        }

        else if ('Array' !== items.constructor.name)
            items = [items];

        return items.length > 0;

    };

};