Plotting

Plotting

The whole plotting is made through the plot method of the chain object.

You can call it with no argument : it will plot your chain in a matplotlib figure.

The plot method can handle more advanced features, such as plotting a target or plotting multiple chain in the same figure.

Plotting multiple targets on the same figure

Say you have two chains left_arm and right_arm, each one representing an arm of an humanoid, and you want to display them on the same figure.

You only have to pass the same matplotlib axes object, say ax, to the plot method.

# Use the same axes object on your plot method
left_arm.plot(joints, ax)
right_arm.plot(joints, ax)

# Display you axes object
matplotlib.pyplot.show()

For example :

Creating an axes object

To create an axes object, you can use this snippet :

# Import the 3D packages of matplotlib
import matplotlib.pyplot
from mpl_toolkits.mplot3d import Axes3D

# Create your axes object
ax = matplotlib.pyplot.figure().add_subplot(111, projection='3d')

Plotting a target with your chain

For inverse kinematics, it can be useful to display the target of your chain along of your chain. To achieve this, just pass a 3D vector to the target parameter of the plot method.