RobotWrapper reduceModel -> buildReducedRobot

bindings/python/pinocchio/robot_wrapper.py

@@ -175,18 +175,18 @@ class RobotWrapper(object):
     def framesForwardKinematics(self, q):
         pin.framesForwardKinematics(self.model, self.data, q)
 
-    def reduceModel(self,
-                    list_of_joints_to_lock,
-                    reference_configuration=None):
+    def buildReducedRobot(self,
+                          list_of_joints_to_lock,
+                          reference_configuration=None):
         """
-          Reduced the robot model given a list of joints to lock.
+          Build a reduced robot model given a list of joints to lock.
           Parameters:
           \tlist_of_joints_to_lock: list of joint indexes/names to lock.
           \treference_configuration: reference configuration to compute the
           placement of the lock joints. If not provided, reference_configuration
-        defaults to the robot's neutral configuration.
+          defaults to the robot's neutral configuration.
 
-        NOTE: This operation is not reversible, the original model is lost.
+          Returns: a new robot model.
         """
 
         # if joint to lock is a string, try to find its index
@@ -205,9 +205,9 @@ class RobotWrapper(object):
             list_of_geom_models=[self.visual_model, self.collision_model],
             list_of_joints_to_lock=lockjoints_idx,
             reference_configuration=reference_configuration)
-        self.model, self.visual_model, self.collision_model = model, geom_models[
-            0], geom_models[1]
-        self.rebuildData()
+
+        return RobotWrapper(model=model, visual_model=geom_models[0],
+                            collision_model=geom_models[1])
 
     def getFrameJacobian(self, frame_id, rf_frame=pin.ReferenceFrame.LOCAL):
         """

examples/build-reduced-model.py

@@ -59,16 +59,16 @@ print('joints to lock (only ids):', jointsToLockIDs)
 print('reduced model: dim=' + str(len(model_reduced.joints)))
 print('-' * 30)
 
-# Option 4: Build a RobotWrapper and reduce the model using the wrapper
+# Option 4: Build a reduced model of a robot using RobotWrapper
 # reference_configuration is optional: if not provided, neutral configuration used
 # you can even mix joint names and joint ids
 mixed_jointsToLockIDs = [jointsToLockIDs[0], 'wrist_2_joint', 'wrist_3_joint']
 robot = pin.RobotWrapper.BuildFromURDF(urdf_filename, mesh_dir)
-robot.reduceModel(list_of_joints_to_lock=mixed_jointsToLockIDs,
-                  reference_configuration=initialJointConfig)
+reduced_robot = robot.buildReducedRobot(list_of_joints_to_lock=mixed_jointsToLockIDs,
+                                        reference_configuration=initialJointConfig)
 
 # Check dimensions of the reduced model and joint info
 print('mixed joints to lock (names and ids):', mixed_jointsToLockIDs)
-print('RobotWrapper reduced model: dim=' + str(len(robot.model.joints)))
+print('RobotWrapper reduced model: dim=' + str(len(reduced_robot.model.joints)))
 for jn in robot.model.joints:
     print(jn)