Display a model using GepettoViewer

# NOTE: this example needs gepetto-gui to be installed
# usage: launch gepetto-gui and then run this test
 
import sys
from pathlib import Path
 
import pinocchio as pin
from pinocchio.visualize import GepettoVisualizer
 
# Load the URDF model.
# Conversion with str seems to be necessary when executing this file with ipython
pinocchio_model_dir = Path(__file__).parent.parent / "models"
 
model_path = pinocchio_model_dir / "example-robot-data/robots"
mesh_dir = pinocchio_model_dir
urdf_filename = "talos_reduced.urdf"
urdf_model_path = model_path / "talos_data/robots" / urdf_filename
 
model, collision_model, visual_model = pin.buildModelsFromUrdf(
    urdf_model_path, mesh_dir, pin.JointModelFreeFlyer()
)
viz = GepettoVisualizer(model, collision_model, visual_model)
 
# Initialize the viewer.
try:
    viz.initViewer()
except ImportError as err:
    print(
        "Error while initializing the viewer. "
        "It seems you should install gepetto-viewer"
    )
    print(err)
    sys.exit(0)
 
try:
    viz.loadViewerModel("pinocchio")
except AttributeError as err:
    print(
        "Error while loading the viewer model. "
        "It seems you should start gepetto-viewer"
    )
    print(err)
    sys.exit(0)
 
# Display a robot configuration.
q0 = pin.neutral(model)
viz.display(q0)
 
# Display another robot.
viz2 = GepettoVisualizer(model, collision_model, visual_model)
viz2.initViewer(viz.viewer)
viz2.loadViewerModel(rootNodeName="pinocchio2")
q = q0.copy()
q[1] = 1.0
viz2.display(q)