Loading the model

Python

from pathlib import Path
from sys import argv
 
import pinocchio
 
# This path refers to Pinocchio source code but you can define your own directory here.
pinocchio_model_dir = Path(__file__).parent.parent / "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 / "example-robot-data/robots/ur_description/urdf/ur5_robot.urdf"
    if len(argv) < 2
    else argv[1]
)
 
# Load the urdf model
model = pinocchio.buildModelFromUrdf(urdf_filename)
print("model name: " + model.name)
 
# Create data required by the algorithms
data = model.createData()
 
# Sample a random configuration
q = pinocchio.randomConfiguration(model)
print(f"q: {q.T}")
 
# Perform the forward kinematics over the kinematic tree
pinocchio.forwardKinematics(model, data, q)
 
# 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(name, *oMi.translation.T.flat))

C++

#include "pinocchio/parsers/urdf.hpp"
 
#include "pinocchio/algorithm/joint-configuration.hpp"
#include "pinocchio/algorithm/kinematics.hpp"
 
#include <iostream>
 
// PINOCCHIO_MODEL_DIR is defined by the CMake but you can define your own directory here.
#ifndef PINOCCHIO_MODEL_DIR
  #define PINOCCHIO_MODEL_DIR "path_to_the_model_dir"
#endif
 
int main(int argc, char ** argv)
{
  using namespace pinocchio;
 
  // You should change here to set up your own URDF file or just pass it as an argument of this
  // example.
  const std::string urdf_filename =
    (argc <= 1) ? PINOCCHIO_MODEL_DIR
                    + std::string("/example-robot-data/robots/ur_description/urdf/ur5_robot.urdf")
                : argv[1];
 
  // Load the urdf model
  Model model;
  pinocchio::urdf::buildModel(urdf_filename, model);
  std::cout << "model name: " << model.name << std::endl;
 
  // Create data required by the algorithms
  Data data(model);
 
  // Sample a random configuration
  Eigen::VectorXd q = randomConfiguration(model);
  std::cout << "q: " << q.transpose() << std::endl;
 
  // Perform the forward kinematics over the kinematic tree
  forwardKinematics(model, data, q);
 
  // Print out the placement of each joint of the kinematic tree
  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;
}