diff --git a/panda/src/egg/eggGroupUniquifier.cxx b/panda/src/egg/eggGroupUniquifier.cxx
index 26fe187f2d..fa84063164 100644
--- a/panda/src/egg/eggGroupUniquifier.cxx
+++ b/panda/src/egg/eggGroupUniquifier.cxx
@@ -29,10 +29,16 @@ TypeHandle EggGroupUniquifier::_type_handle;
 ////////////////////////////////////////////////////////////////////
 //     Function: EggGroupUniquifier::Constructor
 //       Access: Public
-//  Description:
+//  Description: If filter_names is true, then the group names will be
+//               coerced into a fairly safe, standard convention that
+//               uses no characters other than a-z, A-Z, 0-9, and
+//               underscore.  If filter_names is false, the group
+//               names will be left unchanged.
 ////////////////////////////////////////////////////////////////////
 EggGroupUniquifier::
-EggGroupUniquifier() {
+EggGroupUniquifier(bool filter_names)
+  : _filter_names(filter_names)
+{
 }
 
 ////////////////////////////////////////////////////////////////////
@@ -62,6 +68,9 @@ get_category(EggNode *node) {
 string EggGroupUniquifier::
 filter_name(EggNode *node) {
   string name = node->get_name();
+  if (!_filter_names) {
+    return name;
+  }
   nassertr(!name.empty(), string());
 
   string result;
diff --git a/panda/src/egg/eggGroupUniquifier.h b/panda/src/egg/eggGroupUniquifier.h
index ba9f07282f..e3864aa86b 100644
--- a/panda/src/egg/eggGroupUniquifier.h
+++ b/panda/src/egg/eggGroupUniquifier.h
@@ -32,13 +32,16 @@
 ////////////////////////////////////////////////////////////////////
 class EXPCL_PANDAEGG EggGroupUniquifier : public EggNameUniquifier {
 PUBLISHED:
-  EggGroupUniquifier();
+  EggGroupUniquifier(bool filter_names = true);
 
   virtual string get_category(EggNode *node);
   virtual string filter_name(EggNode *node);
   virtual string generate_name(EggNode *node,
                                const string &category, int index);
 
+private:
+  bool _filter_names;
+
 public:
   static TypeHandle get_class_type() {
     return _type_handle;
diff --git a/pandatool/src/xfileegg/xFileToEggConverter.cxx b/pandatool/src/xfileegg/xFileToEggConverter.cxx
index e002f0d968..43fc073441 100644
--- a/pandatool/src/xfileegg/xFileToEggConverter.cxx
+++ b/pandatool/src/xfileegg/xFileToEggConverter.cxx
@@ -141,7 +141,7 @@ convert_file(const Filename &filename) {
 
   if (_make_char) {
     // Now make sure that each joint has a unique name.
-    EggGroupUniquifier uniquifier;
+    EggGroupUniquifier uniquifier(false);
     uniquifier.uniquify(_dart_node);
   }