Fix axis reset of unmapped bones on retargeting

editor/import/3d/post_import_plugin_skeleton_rest_fixer.cpp

@@ -472,13 +472,20 @@ void PostImportPluginSkeletonRestFixer::internal_process(InternalImportCategory
 					int prof_idx = profile->find_bone(src_bone_name);
 					if (prof_idx >= 0) {
 						tgt_rot = src_pg.inverse() * prof_skeleton->get_bone_global_rest(prof_idx).basis; // Mapped bone uses reference pose.
-					}
-					/*
-					// If there is rest-relative animation, this logic may be work fine, but currently not so...
 					} else {
-						// tgt_rot = src_pg.inverse() * old_skeleton_global_rest[src_idx].basis; // Non-Mapped bone keeps global rest.
+						bool has_mapped_child = false;
+						for (int i = 0; i < src_children.size(); i++) {
+							StringName child_bone_name = is_renamed ? StringName(src_skeleton->get_bone_name(src_children[i])) : bone_map->find_profile_bone_name(src_skeleton->get_bone_name(src_children[i]));
+							if (profile->has_bone(child_bone_name)) {
+								has_mapped_child = true;
+								break;
+							}
+						}
+
+						if (!has_mapped_child) {
+							tgt_rot = src_pg.inverse() * old_skeleton_global_rest[src_idx].basis; // Non-Mapped bone without mapped children keeps global rest.
+						}
 					}
-					*/
 				}
 
 				if (src_skeleton->get_bone_parent(src_idx) >= 0) {