robot-wrapper-viewer.py

#
# In this short script, we show how to use RobotWrapper
# integrating different kinds of viewers
#

import pinocchio as pin
from pinocchio.robot_wrapper import RobotWrapper
from pinocchio.visualize import (GepettoVisualizer, MeshcatVisualizer)
from sys import argv
import os
from os.path import dirname, join, abspath

# If you want to visualize the robot in this example,
# you can choose which visualizer to employ
# by specifying an option from the command line:
# GepettoVisualizer: -g
# MeshcatVisualizer: -m
VISUALIZER = None
if len(argv)>1:
    opt = argv[1]
    if opt == '-g':
        VISUALIZER = GepettoVisualizer
    elif opt == '-m':
        VISUALIZER = MeshcatVisualizer
    else:
        raise ValueError("Unrecognized option: " + opt)

# Load the URDF model with RobotWrapper
# Conversion with str seems to be necessary when executing this file with ipython
pinocchio_model_dir = join(dirname(dirname(str(abspath(__file__)))),"models")

model_path = join(pinocchio_model_dir,"example-robot-data/robots")
mesh_dir = pinocchio_model_dir
urdf_filename = "talos_reduced.urdf"
urdf_model_path = join(join(model_path,"talos_data/robots"),urdf_filename)

robot = RobotWrapper.BuildFromURDF(urdf_model_path, mesh_dir, pin.JointModelFreeFlyer())

# alias
model = robot.model
data = robot.data

# do whatever, e.g. compute the center of mass position expressed in the world frame
q0 = robot.q0
com = robot.com(q0)

# This last command is similar to:
com2 = pin.centerOfMass(model,data,q0)

# Show model with a visualizer of your choice
if VISUALIZER:
    robot.setVisualizer(VISUALIZER())
    robot.initViewer()
    robot.loadViewerModel("pinocchio")
    robot.display(q0)