[examples] Improve and test overview-urdf.py

examples/CMakeLists.txt

@@ -40,7 +40,7 @@ IF(BUILD_PYTHON_INTERFACE)
   SET(${PROJECT_NAME}_PYTHON_EXAMPLES
     i-inverse-kinematics
     overview-simple
-    #overview-urdf
+    overview-urdf
     )
 
   FOREACH(EXAMPLE ${${PROJECT_NAME}_PYTHON_EXAMPLES})

examples/overview-urdf.cpp

@@ -33,8 +33,10 @@ int main(int argc, char ** argv)
   forwardKinematics(model,data,q);
 
   // Print out the placement of each joint of the kinematic tree
-  for(JointIndex joint_id = 1; joint_id < (JointIndex)model.njoints; ++joint_id)
-    std::cout << model.names[joint_id] << "\t\t: "
+  for(JointIndex joint_id = 0; joint_id < (JointIndex)model.njoints; ++joint_id)
+    std::cout << std::setw(24) << std::left
+              << model.names[joint_id] << ": "
+              << std::fixed << std::setprecision(2)
               << data.oMi[joint_id].translation().transpose()
               << std::endl;
 }

examples/overview-urdf.py

 import pinocchio
 from sys import argv
+from os.path import dirname, join, abspath
 
-filename = "ur5.urdf" if len(argv)<2 else argv[1]
-model    = pinocchio.buildModelFromUrdf(filename)
+# This path refers to Pinocchio source code but you can define your own directory here.
+pinocchio_model_dir = join(dirname(dirname(abspath(__file__))), 'models')
+
+# You should change here to set up your own URDF file or just pass it as an argument of this example.
+urdf_filename = pinocchio_model_dir + '/others/robots/ur_description/urdf/ur5_robot.urdf' if len(argv)<2 else argv[1]
+
+# Load the urdf model
+model    = pinocchio.buildModelFromUrdf(urdf_filename)
+
+# Create data required by the algorithms
 data     = model.createData()
+
+# Sample a random configuration
 q        = pinocchio.randomConfiguration(model)
-print('q = ', q.T)
+print('q: %s' % q.T)
 
+# Perform the forward kinematics over the kinematic tree
 pinocchio.forwardKinematics(model,data,q)
 
-for k in range(model.njoints):
+# Print out the placement of each joint of the kinematic tree
+for name, oMi in zip(model.names, data.oMi):
     print(("{:<24} : {: .2f} {: .2f} {: .2f}"
-          .format( model.names[k], *data.oMi[k].translation.T.flat )))
+          .format( name, *oMi.translation.T.flat )))