pinocchio库使用教程(三)

几何模型

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"
 
model_path = Path(
    (pinocchio_model_dir / "example-robot-data/robots") if len(argv) < 2 else argv[1]
)
mesh_dir = pinocchio_model_dir
urdf_model_path = model_path / "ur_description/urdf/ur5_robot.urdf"
 
# Load the urdf model
model, collision_model, visual_model = pinocchio.buildModelsFromUrdf(
    urdf_model_path, mesh_dir
)
print("model name: " + model.name)
 
# Create data required by the algorithms
data, collision_data, visual_data = pinocchio.createDatas(
    model, collision_model, visual_model
)
 
# 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)
 
# Update Geometry models
pinocchio.updateGeometryPlacements(model, data, collision_model, collision_data)
pinocchio.updateGeometryPlacements(model, data, visual_model, visual_data)
 
# Print out the placement of each joint of the kinematic tree
print("\nJoint placements:")
for name, oMi in zip(model.names, data.oMi):
    print("{:<24} : {: .2f} {: .2f} {: .2f}".format(name, *oMi.translation.T.flat))
 
# Print out the placement of each collision geometry object
print("\nCollision object placements:")
for k, oMg in enumerate(collision_data.oMg):
    print("{:d} : {: .2f} {: .2f} {: .2f}".format(k, *oMg.translation.T.flat))
 
# Print out the placement of each visual geometry object
print("\nVisual object placements:")
for k, oMg in enumerate(visual_data.oMg):
    print("{:d} : {: .2f} {: .2f} {: .2f}".format(k, *oMg.translation.T.flat))