diff --git a/robosuite/models/base.py b/robosuite/models/base.py
index 52e6f98d47..ae23f33b00 100644
--- a/robosuite/models/base.py
+++ b/robosuite/models/base.py
@@ -205,6 +205,26 @@ def get_element_names(self, root, element_type):
             names += self.get_element_names(child, element_type)
         return names
 
+    # @staticmethod
+    # def _get_default_classes(default):
+    #     """
+    #     Utility method to convert all default tags into a nested dictionary of values -- this will be used to replace
+    #     all elements' class tags inline with the appropriate defaults if not specified.
+
+    #     Args:
+    #         default (ET.Element): Nested default tag XML root.
+
+    #     Returns:
+    #         dict: Nested dictionary, where each default class name is mapped to its own dict mapping element tag names
+    #             (e.g.: geom, site, etc.) to the set of default attributes for that tag type
+    #     """
+    #     # Create nested dict to return
+    #     default_dic = {}
+    #     # Parse the default tag accordingly
+    #     for cls in default:
+    #         default_dic[cls.get("class")] = {child.tag: child for child in cls}
+    #     return default_dic
+
     @staticmethod
     def _get_default_classes(default):
         """
@@ -218,13 +238,50 @@ def _get_default_classes(default):
             dict: Nested dictionary, where each default class name is mapped to its own dict mapping element tag names
                 (e.g.: geom, site, etc.) to the set of default attributes for that tag type
         """
-        # Create nested dict to return
-        default_dic = {}
-        # Parse the default tag accordingly
+        def _parse(cur_element, record, parent_name=None):
+            cur_record = {'parent': parent_name, 'data': {}}
+            record[cur_element.get('class')] = cur_record
+            for child_element in cur_element:
+                if child_element.tag == 'default':
+                    # cur_record['parent'] = cur_element.get('class')
+                    _parse(child_element,
+                            record,
+                            parent_name=[cur_element.get('class')] if parent_name
+                            is None else parent_name + [cur_element.get('class')])
+                else:
+                    cur_record['data'][child_element.tag] = child_element
+           
+        record = {}
         for cls in default:
-            default_dic[cls.get("class")] = {child.tag: child for child in cls}
+            _parse(cls, record)
+        # Update
+        for cls_name, cls_record in record.items():
+            if cls_record['parent'] is None:
+                continue
+            for parent_cls_name in cls_record['parent']:
+                for element_name, element in cls_record['data'].items():
+                    for p_element_name, p_element in record[parent_cls_name][
+                            'data'].items():
+                        if element.tag == p_element.tag:
+                            for attr_name, attr_value in p_element.items():
+                                if attr_name not in element.attrib:
+                                    element.set(attr_name, attr_value)
+                # Update child element
+                for p_element_name, p_element in record[parent_cls_name]['data'].items():
+                    if p_element.tag not in record[cls_name]['data']:
+                        record[cls_name]['data'][p_element.tag] = p_element
+        print(f"record: {record}")
+        # Build default_dic
+        default_dic = {}
+        for cls_name, cls_record in record.items():
+            default_dic[cls_name] = {
+                element.tag: element
+                for element in cls_record['data'].values()
+            }
+        print(f"default_dic: {default_dic}")
         return default_dic
 
+
     def _replace_defaults_inline(self, default_dic, root=None):
         """
         Utility method to replace all default class attributes recursively in the XML tree starting from @root